FR3021050A1 - PROCESS FOR PREPARING BORINIC ACID - Google Patents

Abstract

The present invention relates to a process for the preparation of boric acids.

Description

The present invention relates to a process for the preparation of borinic acids. Boric acids are important intermediates in the synthesis of compounds of interest, especially in the agrochemical or pharmaceutical industry, and are also of great economic interest for their use in various fields, for example as antibiotics, antiviral compounds, antiparasitic compounds, or enzyme stabilizers. Borinic acids are compounds generally obtained by the addition of strong organometallic on a trialkoxyborane. Such syntheses are for example described in application WO 03/059916 and by Liting Niu et al. (Adv Synth Synth 2013, 355, 3625). This type of synthesis has many problems, particularly related to the competitive formation of many by-products, including triorganoboranes and tetraorganoborates. These by-products can not be easily avoided, or at the expense of conversion of the starting materials. Indeed, the fact of placing for example at -60 ° C during the addition limits the formation of by-products, but does not allow an acceptable conversion, while being below 0 ° C allows a better conversion, while promoting the appearance of by-products.

The addition of said organometallic at a temperature of -60 ° C to 0 ° C is also not satisfactory, because it allows neither a good conversion, nor the limitation of the appearance of by-products. In addition, these syntheses require perfect control of the stoichiometry, always in order to avoid the formation of triorganoboranes and tetraorganoborates.

Thus, one of the objectives of the present invention is to prepare boric acids without formation of by-products, including triorganoboranes and tetraorganoborates. Another object of the invention is to prepare boric acids with good yields, in particular greater than 50%, 60%, 70% or 80%.

Another object of the invention is to prepare borinic acids by a simple and rapid process. Another object of the invention is to prepare borinic acids by a process that does not require strict control of the stoichiometry of the reagents.

Another object of the invention is to prepare boric acids by a process whose key step is likely to be carried out at a temperature greater than or equal to room temperature. The invention therefore relates to the use of a dialkylaminoborane and at least one organometallic compound for carrying out a process for the preparation of a borinic acid, without formation of triorganoborane or tetraorganoborate. Surprisingly, the inventors have demonstrated that the use of a dialkylaminoborane makes it possible to obtain a borinic acid without formation of triorganoborane or tetraorganoborate, with good yields, and this, without it being necessary to control perfectly the stoichiometry of the reaction. Indeed, the inventors were surprised to find that said dialkylaminoborane is reactive at low temperature, and that the intermediate formed is stable at 0 ° C., at room temperature and up to 60 ° C., preventing the formation of sub-bases. reaction products. By "dialkylaminoborane" is meant a compound comprising a boron atom substituted with a dialkylamine. By "triorganoborane" is meant a compound comprising a boron atom bonded to three groups, said three groups comprising at least one carbon atom bonded to at least one hydrogen atom. By "tetraorganoborate" is meant an anion comprising a boron atom bonded to four groups, said four groups comprising at least one carbon atom bonded to at least one hydrogen atom. By "no formation of triorganoborane or tetraorganoborate" is meant that less than 5 mol%, in particular less than 4%, 3%, 2% or 1%, of said trialkoborane is formed relative to said dialkylaminoborane. of tetraorganoborate. According to an advantageous embodiment, the present invention relates to a use as described above, wherein said dialkylaminoborane has the following formula (II): ## STR2 ## in which R and R 'are identical or different groups chosen from: - alkyl groups containing from 1 to 18 carbon atoms, linear, branched or cyclic, - the arylalkyl groups, the groups R and R 'possibly possibly forming together an alkylene group comprising from 1 to 18 carbon atoms, linear , or branched. By "arylalkyl group" is meant an alkyl group substituted with aryl, said alkyl group having from 1 to 18 carbon atoms and being linear, branched or cyclic. In what follows, in particular with respect to aryls, heteroaryls, alkenyls, alkynyls, alkyls, cycloalkyls, cycloalkenyls, aromatic or nonaromatic heterocyclics, the term "substituent" means substituted with halogens, in particular fluorine, chlorine, bromine or iodine, hydroxy, amino or thio groups optionally protected by "ad hoc" protecting groups, the -ORa, -NHRa, -NRaRb, -SRa groups , -000Ra, -000NHRa, -000NRaRb, -CHO, -CORa, -COOH, -CN, -COORa, -CONHRa, -CONRaRb, -CF3, -NO2, in which Ra and Rb, which are identical or different, represent alkyl groups, aromatic or non-aromatic alkenyls, alkynyls, cycloalkyls, cycloalkenyls, aromatic or heterocyclic alcohols having from 1 to 18 carbon atoms, optionally bearing at least one substituent, the aldehyde groups protected in the form of acetal or thioacetal, the cetyl groups; protected ones in the form of ketal or thioketal, trialkylsilyl groups, alkyl groups having from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, alkenyl groups having from 2 to 18 carbon atoms linear or branched, optionally bearing at least one substituent, alkynyl groups having from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, at least one substituent, heteroaryls having from 2 to 12 carbon atoms, optionally bearing at least one substituent.

According to an advantageous embodiment, the present invention relates to a use as described above, of a dialkylaminoborane, an organometallic compound of formula Ri-M (Ma) and an organometallic compound of formula R2-M (Tub) in which: M represents Li, Cu, MgX 'or ZnX', where X 'is a halogen selected in particular from Cl, Br and I, X is O, S or C, R1 and R2 are the same or different groups selected from alkenyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, alkynyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, aryl groups; comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, heteroaryl groups having from 2 to 12 carbon atoms, optionally bearing at least one substituent, for carrying out re a process for preparing a borinic acid, without formation of triorganoborane or tetraorganoborate.

The term "ad hoc protecting group of a hydroxy group" represents a group intended to protect an alcohol against undesirable reactions during the synthesis steps. The protective groups of the commonly used alcohols are described in Greene, "Protective Groups In Organic Synthesis" (John Wiley & Sons, New York, 1981. Examples of such groups are acetyl, benzoyl, pivaloyl benzyl, trityl, methoxytrityl, dimethoxytrityl, tetrahydropyranyl, and ethers such as methyl, benzyl, allyl, ethoxyethyl, p-methoxyethoxymethyl, methoxymethyl, p-methoxybenzyl, methylthiomethyl, and silyl. The term "ad hoc protecting group of a thio group" represents a group intended to to protect a thiol against undesirable reactions during the synthesis steps The protective groups of commonly used thiols are described in Greene, "Protective Groups In Organic Synthesis" (John Wiley & Sons, New York, 1981) Examples of such groups are benzoyl groups and ethers such as methyl, ethoxyethyl, benzyl, thoxybenzylique and silyl. The term "ad hoc protecting group of an amino group" represents a group intended to protect an amine against undesirable reactions during synthetic steps. The protective groups of commonly used amines are described in Greene (ibid.). Examples of such groups are carbamate, amide and N-alkyl, acetal, N-benzyl, imine, enamine and N-heteroatom derivatives. In particular, the amine protecting groups include formyl, acetyl, benzoyl, pivaloyl, phenysulfonyl, p-toluenesulfonyl (tosyl), benzyl, t-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz) and fluorenylmethyloxycarbonyl (Fmoc). According to an advantageous embodiment, the present invention relates to a use as described above, wherein said organometallic is of formula (IV) below: M-R2-X-R1-M (IV) in which: M represents Li, Cu , MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I, X represents 0, S or C, R1 and R2 are identical or different groups chosen from: - alkenyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - linear or branched alkynyl groups containing 2 to 18 carbon atoms, optionally bearing at least one substituent, - aryl groups containing from 6 to 18 atoms of carbon, optionally bearing at least one substituent, - heteroaryl groups having from 2 to 12 carbon atoms, optionally bearing at least one substituent. According to an advantageous embodiment, the present invention relates to a use as described above, wherein said borinic acid has the following formula (I): ## STR2 ## in which: n is equal to 0 or 1, - X represents 0, S or C, - represents a single bond when n is 1, and represents no bond when n is 0, - R1 and R2 are the same or different groups selected from: alkenyl groups comprising from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, linear or branched alkynyl groups comprising 2 to 18 carbon atoms, optionally bearing at least one substituent, aryl groups having 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryl groups having from 2 to 12 carbon atoms, optionally bearing at least one substituent. The invention also relates to a process for preparing a (dialkyamino) (diorgano) borane, a borinic acid or a borinic ester comprising: - a step of contacting a dialkyaminoborane and at least one organometallic compound in a solvent for obtaining said (dialkyamino) (diorgano) borane, without formation of triorganoborane or tetraorganoborate, - optionally, a step of hydrolysis of said (dialkyamino) (diorgano) borane to obtain said borinic acid, and - optionally a step of contacting said boric acid with a compound comprising a hydroxyl group to obtain said borinic ester. The invention also relates to a process for the preparation of a borinic acid or a borinic ester, comprising: a step of contacting a dialkyaminoborane and at least one organometallic compound in a solvent to obtain said dialkyamino; (diorgano) borane, without formation of triorganoborane or tetraorganoborate, - a step of hydrolyzing said (dialkyamino) (diorgano) borane to obtain said borinic acid, and - optionally a step of bringing said boric acid into contact with a compound comprising a hydroxyl group to obtain said boric ester. The invention also relates to a process for preparing a borinic acid comprising: - a step of contacting a dialkyaminoborane and at least one organometallic compound in a solvent to obtain said (dialkyamino) (diorgano) borane, without formation of triorganoborane or tetraorganoborate, and - a step of hydrolyzing said (dialkyamino) (diorgano) borane to obtain said borinic acid.

According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of the following formula (I): embedded image in which: is 0 or 1, - X represents 0, S or C, - represents a single bond when n is 1, and represents no bond when n is 0, - R1 and R2 are the same or different groups chosen from: - alkenyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, heteroaryl groups containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, said process comprising: a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II) below: H2B-NRR '(II) in which R and R' are identical or different groups chosen from: - the alkyl groups comprising from 1 to 18 carbon atoms, linear, branched or cyclic, the arylalkyl groups, the groups R and R 'possibly possibly forming together an alkylene group comprising 1 to 18 carbon atoms, linear or branched, and - when n is equal to 0: o an organometallic compound of formula (Ma) below: Ri-M (Ma) in which R1 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a chosen halogen in particular from Cl, Br and I, and o an organometallic compound of formula (Tub) R2-M (Tub) in which R2 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X representing a halogen selected in particular from Cl, Br and I, said contacting with the compounds of formula (Ma) and (Tub) being simultaneous or sequential, OR - when n is 1, an organometallic compound of formula (IV) below: M-R2-X-R1-M (IV) in which R2 , R1 and M are as defined above, and wherein X represents 0, S or C, to obtain said (dialkyamino) (diorgano) borane of the following formula (V): 1 R [X B-NRR '% R2 ( V) - a step of hydrolyzing said (dialkyamino) (diorgano) borane of formula (V) to obtain said borinic acid of formula (I) below: [) (1 / \ B-OH% R2 (I) in which R1 , R2, X and n are as defined above. According to an advantageous embodiment, the present invention relates to a method as described above, wherein said contacting is between: said dialkyaminoborane of formula H 2B-NRR '(II), and - when n is equal to 0 said organometallic compound of formula R1-M (Ma) at a concentration of from 1.0 to 5.0 equivalents relative to said dialkylaminoborane, in particular from 1.0 to 2.5 equivalents, more particularly from 1.0 to 1.6 equivalents, and o said organometallic compound of formula R2-M (Tub), at a concentration of 1.0 to 5.0 equivalents relative to said dialkylaminoborane, in particular from 1.0 to 2.5 equivalents, more particularly from 1.0 to 1.6 equivalents, OR - when n is equal to 1, said organometallic compound of formula M-R2-X-R1-M (IV), at a concentration of from 0.95 to 5, 0 equivalents with respect to said dialkylaminoborane, in particular from 0.95 to 2.5 equivalents, more particularly From 0.95 to 1.6 equivalents, when n is 0, and R2 is the same as R1, said dialkylaminoborane of the formula H2B-NRR '(II) is contacted with said organometallic compound of formula R1-M (Ma), at a concentration of from 2.0 to 10.0 equivalents relative to said dialkylaminoborane, in particular from 2.0 to 5.0 equivalents, more preferably from 2.0 to 3.2 equivalents. According to an advantageous embodiment, the present invention relates to a process as described above, in which the groups R 1 and R 2 are identical or different groups chosen from: aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryl groups having from 2 to 12 carbon atoms, optionally bearing at least one substituent, R1 and R2, which may be identical or different, in particular representing an aryl comprising from 6 to 18 carbon atoms, optionally bearing at least one at least one substituent, more particularly a phenyl optionally bearing at least one substituent. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of formula (I) in which R2 is identical to R1. According to an advantageous embodiment, the present invention relates to a process, as described above, for preparing a borinic acid of formula (I) in which: R 1 represents an aryl comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent, - R2 is identical to R1. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of the following formula (I): ## STR1 ## wherein R 1 and R 2 are as defined above, said process comprising: - a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II) below: H2B-NRR '(II) in which R and R' are as defined previously, - an organometallic compound of formula (Ma) below: R 1 -M (Ma) in which R 1 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen chosen in particular from Cl, Br and I, and an organometallic compound of the following formula (Tub): R2-M (Tub) in which R2 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen chosen in particular from Cl, Br and I, said contacting with the compounds of formula (Ma ) and (Tub) being simultaneous or sequential, to obtain said (dialkyamino) (diorgano) borane of formula (V) below: R 1 B-NRR 'R 7 (y) - a step of hydrolysis of said (dialkyamino) (diorgano) borane of formula (V) to obtain said borinic acid of formula (I) below: wherein R 1, R 2, X and n are as previously defined.

According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of formula (I), wherein said step of contacting is a step of bringing into simultaneous contact, in a solvent, between said dialkyaminoborane of formula H2B-NRR '(II), said organometallic compound of formula R1-M (Ma) and said organometallic compound of formula R2-M (Mb).

According to an advantageous embodiment, the present invention relates to a method, as described above, wherein said step of bringing into simultaneous contact comprises an initial simultaneous contact followed by a prolonged contact.

The initial contacting is carried out, for example, by introducing, dropwise, said dialkyaminoborane of formula H2B-NRR '(II) in a mixture comprising said organometallic compound of formula R1-M (Ma) and said organometallic compound of formula R2- M (Tub), to obtain an initial reaction mixture. The initial contacting can also be carried out by introducing dropwise said organometallic compound of formula R1-M (Ma) and said organometallic compound of formula R2-M (Tub) into a mixture comprising said dialkyaminoborane of formula NRR '(II), to obtain an initial reaction mixture. The prolonged contact is for example carried out by stirring the initial reaction mixture. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of formula (I), in which said contacting step is sequential and consists of: a first step contacting, in a solvent, between said dialkylaminoborane of formula H 2B -NRR '(II) and said organometallic compound of formula R 1 -M (Ma), to obtain a reaction medium, and - a second contacting step between said reaction medium and said organometallic compound of formula R2-M (Tub). According to an advantageous embodiment, the present invention relates to a method, as described above, wherein said first and second contacting steps each comprise initial simultaneous contact followed by prolonged contact. In the case of the first contacting step, the initial contacting is carried out, for example, by introducing, dropwise, said dialkyaminoborane of formula H2B-NRR '(II) in a medium comprising said organometallic compound of formula Ri -M (Ma), to obtain an initial reaction mixture.

In the case of the first contacting step, the initial contacting can also be carried out by introducing dropwise said organometallic compound of formula R1-M (Ma) in a medium comprising said dialkyaminoborane of formula H2B-NRR (II), to obtain an initial reaction mixture. In the case of the second contacting step, the initial contacting is carried out for example by introducing dropwise said organometallic compound of formula R2-M (Tub) into the reaction mixture obtained at the end of the reaction. first step of contacting.

In the case of the first and second contacting steps, the prolonged contacting is for example carried out by stirring the initial reaction mixture or the reaction mixture obtained at the end of the second initial contacting, respectively. According to an advantageous embodiment, the initial contacting as defined above is carried out at a temperature of from -100 ° C to 30 ° C, in particular at about -78 ° C or at about 20 ° C. Surprisingly, the inventors have demonstrated that the use of a dialkylaminoborane makes it possible to carry out initial contact at ambient temperature, without formation of triorganoborane or tetraorganoborate, with good yields. According to an advantageous embodiment, the prolonged contacting as defined above is carried out at a temperature of from 0 ° C. to 90 ° C., in particular from 15 ° C. to 75 ° C., more particularly about 20 ° C. or about 70 ° C. Surprisingly, the inventors have demonstrated that the use of a dialkylaminoborane makes it possible to carry out prolonged contact at room temperature, or even at about 60 ° C. or about 70 ° C., without formation of triorganoborane or tetraorganoborate. , with good returns. According to an advantageous embodiment, the prolonged contacting as defined above lasts from 1 hour to 48 hours, in particular from 3 hours to 24 hours. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of formula (I), in which R1 and R2, which may be identical or different, represent an aryl having from 6 to 18 carbon atoms, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of formula (I) in which R2 is identical to R1. According to an advantageous embodiment, the present invention relates to a process, as described above, for preparing a borinic acid of formula (I) in which: R 1 represents an aryl comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent, - R2 is identical to R1. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of the following formula (I): ## STR1 ## in which R 1 , R2 and X are as defined above, said process comprising: - a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II): H2B-NRR '(II) wherein R and R are as defined above, and - an organometallic compound of formula (IV) below: M-R2-X-R1-M (IV) in which R2, R1 and M are as defined above, and in which X represents 0 , S or C, to obtain said (dialkyamino) (diorgano) borane of the following formula (V): ## STR1 ## a step of hydrolysis of said (dialkyamino) (diorgano) borane of formula (V) to obtain said borinic acid of formula (I) below: wherein R 1, R 2 and X are as defined above.

According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of formula (I) in which R1 and R2, which may be identical or different, represent an aryl comprising from 6 to 18 atoms. carbon, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent.

According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic acid of formula (Ic) below: (Ic) in which X is as defined previously, R3, R4, R5 Wherein R6, R7, R8, R9 and R10 are selected from: - halogens, especially fluorine, chlorine, bromine or iodine, - hydroxy, amino or thio groups optionally protected by "ad hoc" protecting groups The groups -ORa, -NHRa, -NRaRb, -SRa, -000Ra, -000NHRa, -000NRaRb, -CHO, -CORa, -COOH, -CN, -COORa, -CONHRa, -CONRaRb, -CF3, -NO2, in which Ra and Rb, which are identical or different, represent aromatic or nonaromatic linear or branched alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aromatic or heterocyclic groups containing from 1 to 18 carbon atoms, optionally bearing at least one substituent, protected aldehyde groups in the form of acetal or thioa ketones, protected ketone groups in the form of ketal or thioketal, trialkylsilyl groups, alkyl groups containing from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, alkenyl groups having 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups having 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - aryl groups containing at least one substituent, 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryls containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, said process comprising: a step of contacting, in a solvent, between a dialkyaminoborane of formula (II-1) below: H2B-NRR '(II-1) in which R and R' are as defined above, and an organomethyl compound étalique of formula (IV-1) following: (IV-1) wherein X, R3, R4, R5, R6, R7, R8, R9, R10 and M are as defined above, to obtain said (dialkyamino) (diorgano) borane of the following formula (Vc): (Vc), - :. a step of hydrolyzing said (dialkyamino) (diorgano) borane of formula (V) to obtain said borinic acid of formula (I) below: (I) wherein X, R3, R4, R6, R6, R7, R8, R9 and R10 are as previously defined.

Said hydrolysis step may be carried out according to techniques well known to those skilled in the art. For example, the hydrolysis step can be carried out by addition of methanol and then an aqueous solution of hydrochloric acid, in particular at about -78 ° C.

According to an advantageous embodiment, the present invention relates to a process, as described above, in which M represents Li. The organolithium compounds (Ri-Li or R2-Li) may in certain cases be commercially available. These can also be formed beforehand, or formed in situ, according to a procedure well known to those skilled in the art. The organolithium may in particular be formed by metal / halogen exchange, in particular by the action of sec-BuLi on a halide, for example an aryl halide. According to an advantageous embodiment, the present invention relates to a method, as described above, in which M represents MgX ', X' representing a halogen selected in particular from Cl, Br and I.

Organomagnesium compounds (Ri-MgX 'or R2-MgX') may in some cases be commercially available. These can also be formed beforehand, or formed in situ, according to a procedure well known to those skilled in the art. In particular, organomagnesium compounds may be formed by the action of magnesium on a halide, for example an aryl halide.

In particular, the organomagnesium compounds can be formed under Barbier conditions: there is then brought into contact with said dialkylaminoborane with elements allowing the in situ formation of said organomagnesium, for example bringing said dialkylaminoborane into contact with a medium comprising magnesium and a halide aryl. The invention also relates to a process for preparing a (dialkyamino) (diorgano) borane comprising a step of contacting a dialkyaminoborane and at least one organometallic compound in a solvent to obtain said (dialkyamino) (diorgano) borane, without formation of triorganoborane or tetraorganoborate. According to an advantageous embodiment, the present invention relates to a process, as described above, for preparing a (dialkyamino) (diorgano) borane of formula (V) below: [X B-NRR '% R2 (y) wherein: - n is 0 or 1, - X is 0, S or C, - represents a single bond when n is 1, and represents no bond when n is 0, - R1 and R2 are identical or different groups chosen from: - alkenyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups comprising from 2 to 18 carbon atoms, linear or branched, bearing optionally at least one substituent, aryl groups having from 6 to 18 carbon atoms, optionally bearing at least one substituent, heteroaryl groups containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, said process omprenant: a step of bringing into contact, in a solvent, between: a dialkyaminoborane of formula (II) below: H2B-NRR '(II) in which R and R' are identical or different groups chosen from: alkyl groups having from 1 to 18 carbon atoms, linear, branched or cyclic, the arylalkyl groups, the groups R and R 'optionally being able to form together an alkylene group comprising from 1 to 18 carbon atoms, linear or branched, and when n is 0: an organometallic compound of formula (Ma) below: R 1 -M (Ma) in which R 1 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I, and o an organometallic compound of formula (Tub) R2-M (Tub) in which R2 is as defined above, and M represents Li, Cu, MgX 'or ZnX ', X' representing a halogen selected in particular from Cl, Br and I, said setting contact with the compounds of formula (Ma) and (Tub) being simultaneous or sequential, OR - when n is equal to 1, an organometallic compound of formula (IV) below: M-R2-X-R1-M (IV) in which R2, R1 and M are as defined above, and wherein X represents 0, S or C, to obtain said (dialkyamino) (diorgano) borane of the following formula (V): [R, 1 XB NRR 'rn) \ R2 (V) wherein R1, R2, X and n are as previously defined.

According to an advantageous embodiment, the present invention relates to a method as described above, wherein said contacting is between: said dialkyaminoborane of formula H2B-NRR '(II), and - when n is equal to 0: said organometallic compound of formula R1-M (Ma), at a concentration of from 1.0 to 5.0 equivalents relative to said dialkylaminoborane, and o said organometallic compound of formula R2-M (Tub), at a concentration of from 1.0 to 5.0 equivalents relative to said dialkylaminoborane, OR - when n is 1, said organometallic compound of formula M-R2-X-R1-M (IV) at a concentration of 1.0 to 5 0 equivalents to said dialkylaminoborane. According to an advantageous embodiment, the present invention relates to a process as described above, in which the groups R 1 and R 2 are identical or different groups chosen from: aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryl groups having from 2 to 12 carbon atoms, optionally bearing at least one substituent, R1 and R2, which may be identical or different, in particular representing an aryl comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent. According to an advantageous embodiment, the present invention relates to a method, as described above, of preparing a (dialkyamino) (diorgano) borane of formula (V) in which R2 is identical to R1.

According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of formula (V) in which: R 1 represents an aryl comprising from 6 to 18 atoms of carbon, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent, - R2 is identical to R1. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of the following formula (V): ## STR2 ## in which R1 and R2 are as defined above, said process comprising: - a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II): H2B-NRR '(II) in which R and R' are as defined previously, - an organometallic compound of formula (Ma) below: R1-M (Ma) in which R1 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen chosen in particular from Cl, Br and I, and - an organometallic compound of formula (Tub) R2-M (Tub) in which R2 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'represents a halogen selected in particular from Cl, Br and I, said contacting with the compounds of formula (Ma) and (Tub) being simultaneous or sequential, to obtain said (dialkyamino) (diorgano) borane of formula (V) below: R 1, B-NRR 'R 7 (V) in which R 1, R 2, X and n are as defined above. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of formula (V), in which said step of bringing into contact is a step of placing in simultaneous contact, in a solvent, between said dialkyaminoborane of formula H2B-NRR '(II), said organometallic compound of formula R1-M (Ma) and said organometallic compound of formula R2-M (Tub).

According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of formula (V), in which said step of bringing into contact consists of: first step of contacting, in a solvent, between said dialkyaminoborane of formula H2B-NRR '(II) and said organometallic compound of formula R1-M (Ma), to obtain a reaction medium, and - a contacting step between said reaction medium and said organometallic compound of formula R2-M (Tub).

According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of formula (V), in which R1 and R2, identical or different, represent an aryl comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of formula (V) in which R2 is identical to R1. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of formula (V) in which: R 1 represents an aryl comprising from 6 to 18 atoms of carbon, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent, - R2 is identical to R1. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of the following formula (V): ## STR2 ## ) wherein R1, R2 and X are as defined above, said process comprising: - a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II): H2B-NRR '(II) in which R and R 'are as defined above, and - an organometallic compound of formula (IV) below: M-R2-X-R1-M (IV) in which R2, R1 and M are as defined above, and in wherein X is O, S or C, to give said (dialkyamino) (diorgano) borane of the following formula (V): wherein R1, R2 and X are such than previously defined. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a (dialkyamino) (diorgano) borane of formula (V) in which R1 and R2, identical or different, represent an aryl comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent. According to an advantageous embodiment, the present invention relates to a method, as described above, for the preparation of a (dialkyamino) (diorgano) borane of the following formula (Vc): (Vc), in which X is as defined previously, R3, R4, R5, R6, R7, R8, R9 and R10 being selected from: - halogens, in particular fluorine, chlorine, bromine or iodine, optionally protected hydroxy, amino or thio groups by "ad hoc" protecting groups, the groups -ORa, -NHRa, -NRaRb, -SRa, -000Ra, -000NHRa, -000NRaRb, -CHO, -CORa, -COOH, -CN, -COORa, -CONHRa, -CONRaRb, -CF3, -NO2, in which Ra and Rb, which may be identical or different, represent aromatic or non-aromatic linear or branched alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aromatic or heterocyclic groups containing from 1 to 18 carbon atoms, bearing optionally at least one substituent, the protected aldehyde groups in the form of a keto groups in the form of ketal or thioketal, trialkylsilyl groups, alkyl groups having from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, alkenyl groups comprising 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, alkynyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, aryl groups containing from 6 to 18 atoms of carbon, optionally bearing at least one substituent, heteroaryls having from 2 to 12 carbon atoms, optionally bearing at least one substituent, said process comprising: - a step of contacting, in a solvent, between: - a dialkyaminoborane of following formula (II-1): H2B-NRR '(II-1) in which R and R' are as defined above, and - an organometallic compound of formula (IV-1) below: (IV-1) wherein X and M are as defined above, to obtain said (dialkyamino) (diorgano) borane of formula (Vc): (Vc), wherein X, R3, R4, R5, R6, R7, R8, R9 and R10 are as defined above. According to an advantageous embodiment, the present invention relates to a method, as described above, in which M represents Li. According to an advantageous embodiment, the present invention relates to a method, as described above, in which M represents MgX. X is a halogen selected in particular from Cl, Br and I. The invention also relates to a process for preparing a borinic ester comprising: a step of contacting a dialkyaminoborane and at least one organometallic compound in a solvent for obtaining said (dialkyamino) (diorgano) borane, without formation of triorganoborane or tetraorganoborate, - a step of hydrolyzing said (dialkyamino) (diorgano) borane to obtain said borinic acid, and - a step of contacting said boric acid with a compound comprising a hydroxyl group to obtain said boric ester.

Said contacting and hydrolysis steps correspond to those mentioned above relative to the preparation of borinic acids. According to an advantageous embodiment, the present invention relates to a process, as described above, wherein said compound comprising a hydroxyl group has the following formula (VI): embedded image in which R "is a chosen group among: alkyl groups containing from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, alkenyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, alkynyl groups having from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, heteroaryls having from 2 to 12 atoms of carbon, optionally bearing at least one substituent. According to an advantageous embodiment, R "is chosen from: alkyl groups comprising from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, said substituent being the group -NH 2, the alkenyl groups comprising from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, said substituent being the group -NH 2, alkynyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, said substituent being the group -NH2, aryl groups having from 6 to 18 carbon atoms, optionally bearing at least one substituent, said substituent being the group -NH2, heteroaryls having from 2 to 12 carbon atoms, optionally bearing at least one a substituent, said heteroaryl comprising a nitrogen atom.

In this embodiment, the nitrogen of the -NH 2 or heteroaryl group is capable of forming with the boron a covalent coordination bond. According to an advantageous embodiment, the present invention relates to a process, as described above, wherein said compound comprising a hydroxyl group is ethanolamine or 8-hydroxyquinoline. According to an advantageous embodiment, the present invention relates to a process, as described above, for the preparation of a borinic ester of formula (VII) below: ## STR1 ## in which where: n is 0 or 1, X is 0, S or C, - represents a single bond when n is 1, and represents no bond when n is 0, - R1 and R2 are identical or different groups chosen from: - alkenyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - aryl groups having from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryl groups containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, - R "is a group chosen from: - alkyl groups containing from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, - alkenyl groups comprising from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one a substituent, - alkynyl groups comprising from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryls having 2 to 12 carbon atoms, optionally bearing at least one substituent, R "being in particular chosen from: - alkyl groups containing from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, said substituent being the group -NH2, - alkenyl groups having from 2 to 18 carbon atoms, linear or branched, bearing optional at least one substituent, said substituent being the group -NH 2, - alkynyl groups having 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, said substituent being the group -NH 2, - aryl groups comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, said substituent being the -NH 2 group, - heteroaryls containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, said heteroaryl comprising an atom of nitrogen, said process comprising: - :. a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II) below: H2B-NRR '(II) in which R and R' are identical or different groups chosen from: - the alkyl groups comprising from 1 to 18 carbon atoms, linear, branched or cyclic, the arylalkyl groups, the groups R and R 'possibly possibly forming together an alkylene group comprising 1 to 18 carbon atoms, linear or branched, and - when n is equal to 0: o an organometallic compound of formula (Ma) below: R1-M (Ma) in which R1 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a chosen halogen in particular from Cl, Br and I, and o an organometallic compound of formula (Tub) R2-M (Tub) in which R2 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X representing a halogen selected in particular from Cl, Br and I, said contacting with the compounds of formula (Ma) and (Tub) being simultaneous or sequential, OR - when n is 1, an organometallic compound of formula (IV) below: M-R2-X-R1-M (IV) in which R2 , R1 and M are as defined above, and wherein X represents 0, S or C, to obtain said (dialkyamino) (diorgano) borane of the following formula (V): 1 R [% R X B-NRR ' (y) - a step of hydrolysis of said (dialkyamino) (diorgano) borane of formula (V) to obtain said borinic acid of formula (I) below: R, 1 [X \ .ri / B-0 Hr% R2 (I) wherein R1, R2, X and n are as defined above, and - a step of contacting said borinic acid of formula (I) with a compound comprising a hydroxyl group, of formula (VI) below: HO -R "(VI) wherein R" is as defined above, HO-R "particularly representing ethanolamine or 8-hydroxyquinoline, to obtain said borinic ester of formula (VII): R1 [X. Wherein R 1, R 2, R ", X and n are as previously defined. When the group R "is alkyl, alkenyl, alkynyl or aryl, substituted with -NH2, or when R" is a heteroaryl comprising a nitrogen atom, the nitrogen of said -NH2 group or said heteroaryl is capable of forming with boron a covalent coordination bond. In all the foregoing, said step of contacting the borinic acid of formula (I) with the compound of formula (VI) may for example be carried out by stirring said boric acid and said compound of formula (VI) in ethyl ether at room temperature. In particular, the corresponding borinic ester precipitates and can be isolated by filtration without further purification. EXAMPLES Example 1 Synthesis of Diphenylborinic Acid from Phenyl Lithium and Diisopropylaminoborane To a solution of diisopropylaminoborane (2 mmol, 0.3 ml) in 4 ml of anhydrous THF at 0 ° C., 3.9 ml of a solution of phenyl lithium in dibutyl ether (1.6M, 6.2 mmol) is added dropwise. The reaction medium is stirred at room temperature for 5 hours. The reaction medium is cooled to -78 ° C. and 4 ml of MeOH is added dropwise while maintaining the temperature at -78 ° C. The reaction medium is then stirred at room temperature. The reaction medium is concentrated under vacuum and 10 ml of THF and 15 ml of a 3M aqueous hydrochloric acid solution are added. The reaction medium is allowed to stir at room temperature for 12 hours. The mixture is then extracted with 5 times 15 ml of dichloromethane. The combined organic phases are dried over Na 2 SO 4, filtered and concentrated in vacuo to give a white solid of crude diphenylborinic acid. The crude product is purified by column chromatography on silica (petroleum ether / diethyl ether 90/10) to give pure diphenyl borinic acid (250 mg, 69%). Example 2 Synthesis of Diphenyl Borinic Acid from Aryl Bromide and Diisopropylaminoborane by Metal / Halogen Exchange To a solution of 4-bromoanisole (1.04 ml, 8.3 mmol) in 25 ml of anhydrous THF at -78 ° C., 6.4 ml of sec-BuLi (1.3M, 8.3 mmol) is added dropwise. The reaction medium is stirred at -78 ° C. for 2 h and then 0.53 ml of diisopropylaminoborane (3.3 mmol) are added and the reaction mixture is stirred at room temperature for 3 h 30 min. After cooling to -78 ° C., 6 ml of MeOH are added and the reaction mixture is left to stir at room temperature. After cooling to -78 ° C., 15 ml of a 3M aqueous hydrochloric acid solution are added and the reaction mixture is then stirred for 15 minutes at room temperature. The mixture is then extracted with 5 times 15 ml of dichloromethane. The combined organic phases are dried over Na 2 SO 4, filtered and concentrated in vacuo to give a white solid of crude diphenylborinic acid. The crude product is dissolved in 30 ml of a 10% by weight aqueous NaOH solution and then extracted with 5 times 15 ml of dichloromethane. The aqueous phase is acidified to pH 1 by the addition of a 3M aqueous hydrochloric acid solution until precipitation of borinic acid. The solid is recovered by filtration, drained and dried under vacuum to give 430 mg of bis (methoxyphenyl) borinic acid (53%). Example 3: Synthesis of diphenylborinic acid from Grignard reagent and diisopropylaminoborane. To a suspension of 547 mg of magnesium (22.5 mmol) in 5 ml of anhydrous THF is added dropwise a solution of 4-bromotoluene (2.57 g, 15 mmol) in 10 ml of anhydrous THF and the reaction medium is heated to 70.degree. ° C for 1h30. After cooling to room temperature, the Grignard reagent is added dropwise to a solution of diisopropylaminoborane (0.8 ml, 5 mmol) in 25 ml of anhydrous THF at -78 ° C. The mixture is then stirred for 12 hours at room temperature and then 3M aqueous hydrochloric acid solution is slowly added at -78 ° C. After stirring for 45 minutes at room temperature, the reaction medium is extracted with 5 times 15 ml of dichloromethane. The combined organic phases are dried over Na 2 SO 4, filtered and concentrated in vacuo to give a white solid of crude diphenylborinic acid. The crude product is purified by silica column chromatography (80/20 petroleum ether / dichloromethane) to give the pure bis (tolyl) borinic acid (866 mg, 82%). Example 4 Synthesis of Diphenyl Borinic Acid from Grignard Reagent and Diisopropylaminoborane in Barbier Condition

To a suspension of 547 mg of magnesium (22.5 mmol) and diisopropylaminoborane (0.8 ml, 5 mmol) in 30 ml of anhydrous THF is added dropwise a solution of 4-bromotoluene (2.57 g, 15 mmol) in 10 ml of Anhydrous THF and the reaction medium is heated at 70 ° C. for 5 hours. After cooling to room temperature, 3M aqueous hydrochloric acid solution is slowly added at -78 ° C. After stirring for 45 minutes at room temperature, the reaction medium is extracted with 5 times 15 ml of dichloromethane. The combined organic phases are dried over Na 2 SO 4, filtered and concentrated in vacuo to give a white solid of crude diphenylborinic acid. The crude product is purified by silica column chromatography (70/30 petroleum ether / dichloromethane) to give pure bis (tolyl) borinic acid (805 mg, 77%). Example 5 Synthesis of dibenzoxaborininols from diaryl ethers In a 250 ml two-neck flask equipped with a thermometer and under argon, THF (25 ml), TMEDA (2, 1 eq., 21 mmol, 3.13 mL) and s-BuLi (2.1 eq, 21 mmol). After 5 minutes, the diphenyl ether is added dropwise (1 eq, 10 mmol, 1.59 mL) and the reaction mixture thus obtained is stirred for 1 hour at room temperature. Diisopropylaminoborane (1.05 eq, 10.5 mmol, 1.66 mL) is then added dropwise at -78 ° C, and the reaction medium is stirred for 12 hours at room temperature. The reaction medium is cooled to -78 ° C. and methanol and then a solution of 3M hydrochloric acid are slowly added, the temperature being maintained at -78 ° C. After stirring for 30 minutes at room temperature, the reaction medium is extracted with diethyl ether. The organic phase is extracted with 10% sodium hydroxide solution. The aqueous phase is then slowly acidified with 1M HCl solution until the appearance of a white solid which is filtered to recover the desired product.

General Procedure A: Synthesis of borinic acid (brominated liquid derivative) OH Mg (3.3 eq) iPr2NBH2 (leq),. 1 IR THF, 70 ° C -7 ', ..... 7 ........ 7 RA a suspension of magnesium (16.5 mmol, 401 mg) in a mixture of anhydrous THF (40 mL) and diisopropylaminoborane (5 mmol, 0.8 mL) at room temperature is added the aryl bromide (11 mmol). The reaction mixture was then heated at 70 ° C for 20 h with stirring, then cooled to -78 ° C and quenched with 3M aqueous hydrochloric acid (25 mL). The resulting mixture is stirred at room temperature for 45 minutes. To this solution is added water and diethyl ether (25 ml) and the organic phase is decanted. The aqueous phase is extracted with 6 × 30 ml of dichloromethane. The organic phases are combined, dried over Na2SO4 and Br concentrated in vacuo. The crude borinic acid obtained is then treated according to the general procedures C or D. General procedure B: synthesis of borinic acid (solid brominated derivative) Br Mg (3.3 eq) OH iPr2NBH2 (leq) ... / .... .-1 ......'... / .. `........, .. '1. THF, 70 ° CA a suspension of magnesium (16.5 mmol, 401 ° C). mg) in a mixture of anhydrous THF (30 mL) and diisopropylaminoborane (5 mmol, 0.8 mL), at room temperature is added the aryl bromide (11 mmol) in solution of anhydrous THF (10 mL). The reaction mixture is then heated at 70 ° C for 20 h with stirring. After cooling to room temperature, the mixture is cooled to -78 ° C and quenched with a 3M aqueous hydrochloric acid solution (25 mL). The resulting mixture is allowed to stir at room temperature for 45 minutes. To this solution is added water (25 mL) and diethyl ether (25 mL) and the organic phase is decanted. The aqueous phase is extracted with 6 × 30 ml of dichloromethane. The organic phases are combined, dried over Na 2 SO 4 and concentrated in vacuo. The crude borinic acid obtained is then treated according to the general procedures C or D. General procedure C: ethanolamine treatment / - O, NH 2 B "... 1 + R / 1 RRA an acid suspension Crude borin (5 mmol) in diethyl ether (20 mL) is added ethanolamine (0.36 mL, 6 mmol). A precipitate forms quickly and if necessary, diethyl ether is added to ensure a constant mixture. After 15 h at room temperature, the reaction medium is filtered, the solid is washed with a minimum of diethyl ether and dried under vacuum to give the corresponding borinate.

General procedure D: treatment with 8-hydroxyquinoline OH, yi Et20, TA HONH 2 OH Et 2 O, TA 38 To a suspension of crude borinic acid (5 mmol) in diethyl ether (20 mL) is added 8- hydroxyquinoline (726 mg, 5 mmol). A precipitate forms quickly and if necessary, diethyl ether is added to ensure a constant mixture. After 15 h at room temperature, the reaction medium is filtered, the solid is washed with a minimum of diethyl ether and dried under vacuum to give the corresponding borinate. General Procedure F: Synthesis of Dissymmetric Boric Acid (Liquid Bromine) R 2 Br Mg (1.5 eq) iPr 2 NRBH 2 (1.5 eq) BHNiPr 2 Mg (2.25 eq) R 2 ArBr (1.5 eq) Y.% R THF, 70 ° C R THF, 70 ° C. To a suspension of magnesium (18.7 mmol, 455 mg) in a mixture of anhydrous THF (30 ml) and diisopropylaminoborane (7.5 mmol, 1.2 ml), at room temperature, is added the first aryl bromide (5 mmol). The reaction mixture is then heated at 70 ° C for 20 h with stirring. After returning to room temperature, the THF and excess diisopropylaminoborane under the vacuum of a paddle pump. Anhydrous THF (40 mL) and the second aryl bromide (7.5 mmol) are added at room temperature. The reaction medium is then heated at 70 ° C. for 20 hours. The mixture was cooled to -78 ° C and quenched with 3M aqueous hydrochloric acid solution (25 mL). The resulting mixture is allowed to stir at room temperature for 45 minutes. To this solution is added water (25 mL) and diethyl ether (25 mL) and the organic phase is removed. The aqueous phase is extracted with dichloromethane (6 × 30 ml). The organic phases are combined, dried over Na 2 SO 4 and concentrated in vacuo. The crude borinic acid obtained is then treated according to the general procedures C or D. Example 6: Synthesis of 2 - ((di-m-tolylboryl) oxy) ethanamine O 'N H 2 O 1.046 g of a white solid are obtained from from 11 mmol of 3-bromotoluene using procedure A followed by procedure C. Yield: 82% 1H NMR (300 MHz, DMSO) δ (ppm) 7.26 - 7.10 (m, 4H), 7.01 (t, J = 7.4 Hz, 2H), 6.84 (d, J = 7.4 Hz, 2H), 6.00 (bt, 2H), 3.74 (t, J = 6.4 Hz, 2H), 2.80 (p, J = 6.4 Hz, 2H), 2.22 (s, 6H). 11B NMR (96 MHz, DMSO) δ 4.81 (s). 13C NMR (75 MHz, DMSO) δ 135.2, 132.7, 129.1, 126.9, 125.9, 62.80, 4.79, 21.9. Example 7 Synthesis of 2 - ((di-p-tolylboryl) oxy) ethanamine / - NH 2 B 1.038 g of a white solid are obtained from 11 mmol of 4-bromotoluene using the procedure B followed C. Yield: 69% 1H NMR (300 MHz, DMSO) δ (ppm) 7.25 (d, J = 7.7 Hz, 4H), 6.94 (d, J = 7.7 Hz, 4H), 5.92 (bt, 2H) ), 3.73 (t, J = 6.4 Hz, 2H), 2.80 (t, J = 6.4 Hz, 1H), 2.20 (s, 6H). 11B NMR (96 MHz, DMSO) δ 5.66 (s). EXAMPLE 8 Synthesis of 2 - ((bis (3-methoxyphenyl) boryl) oxy) ethanamine ## STR13 ## 1,180 g of a white solid are obtained from 11 mmol of 3 -bromoanisole using Procedure A followed by Procedure C. Yield: 83% 1H NMR (300 MHz, DMSO) δ (ppm) 7.06 (t, J = 7.8 Hz, 2H), 6.96 (m, 4H), 6.60 ( dd, J = 7.8, 1.7 Hz, 2H), 6.05 (bt, 2H), 3.76 (t, J = 6.4 Hz, 2H), 3.68 (s, 6H), 2.81 (p, J = 6.2 Hz, 2H). 11B NMR (96 MHz, DMSO) δ 5.25 (s). 13C NMR (75 MHz, DMSO) δ 158.2, 127.6, 123.94, 116.9, 110.1, 62.4, 54.50, 41.3. Example 9 Synthesis of 2 - ((bis (4-methoxyphenyl) boryl) oxy) ethanamine MeO OMe 1.205 g of a white solid are obtained from 11 mmol of 4-bromoanisole using procedure A followed by procedure C Yield: 84% 1H NMR (300 MHz, CDCl 3) δ (ppm) 7.26 (d, J = 8.5 Hz, 4H), 6.72 (d, J = 8.5 Hz, 4H), 5.88 (bt, 2H), 3.74 ( t, J = 6.35 Hz, 2H), 3.67 (s, 6H), 2.80 (t, J = 6.35 Hz, 2H). 11B NMR (96 MHz, DMSO) δ 10.33 (s). 13C NMR (101 MHz, DMSO) δ 148.2, 133.3, 131.6, 127.3, 62.4, 41.3, 20.9. Example 10: Synthesis of 2 - ((di (naphthalen-2-yl) boryl) oxy) ethanamine / - 1B, #NH 2 H NMR (300 MHz, DMSO) δ (ppm) 7.95 (s, 2H) , 7.76 (d, J = 7.7 Hz, 4H), 7.73 - 7.61 (m, 4H), 7.44 - 7.30 (m, 4H), 6.34 (bt, 2H), 3.88 (t, J = 6.3 Hz, 2H), 3.02 - 2.88 (p, J = 6.3 Hz, 2H). 11B NMR (96 MHz, DMSO) δ 5.98 (s) 13C NMR (75 MHz, DMSO) δ 132.9, 131.9, 130.8, 129.7, 127.4, 127.21, 125.4, 124.9, 124.3, 64.9, 62.6, 41.6, 15.2. Example 11: Synthesis of (((diphenylboryl) oxy) ethanamine / NH 2 Er 1.024 g of a white solid are obtained from 11 mmol of bromobenzene using Procedure A followed by Procedure C. Yield: 91% 1H NMR (300 MHz, DMSO) δ (ppm) 7.40 (d, J = 6.7 Hz, 4H), 7.13 (t, J = 7.2 Hz, 4H), 7.03 (t, J = 7.2 Hz, 2H), 6.07 (bt, 2H), 3.77 (t, J = 6.35 Hz, 2H), 2.90 - 2.75 (p, J = 6.35 Hz, 2H). 11B NMR (96 MHz, DMSO) δ 4.06 (s). 13C NMR (75 MHz, DMSO) δ 131.5, 126.6, 124.9, 62.4, 41.3.

Example 12: Synthesis of 2 - ((bis (3,4-dimethylphenyl) boryl) oxy) ethanamine O, # 1 \ 1H2 1.106 g of a white solid are obtained from 11 mmol of 4-bromo-o- xylene using procedure A followed by procedure C. Yield: 77% 1H NMR (300 MHz, DMSO) δ (ppm) 7.12 (s, 2H), 7.06 (d, J = 7.4 Hz, 2H), 6.87 (d, J = 7.4 Hz, 2H), 5.87 (bt, 2H), 3.71 (t, J = 6.3 Hz, 2H), 2.78 (p, J = 6.3 Hz, 2H), 2.13 (s, 6H), 2.12 (s, 6H). 11B NMR (96 MHz, DMSO) 5.86 13C NMR (101 MHz, DMSO) 133.4, 133.1, 131.9, 129.2, 127.8, 62.3, 41.3, 19.7, 19.2. 1.235 g of a white solid are obtained from 11 mmol of 4-tert-butyl bromobenzene using procedure A followed by procedure C. Yield: 73% 1H NMR (300 MHz, DMSO) δ (ppm) 7.32 (d , J = 8.2 Hz, 4H), 7.15 (d, J = 8.2 Hz, 4H), 5.98 (bt, 2H), 3.75 (t, J = 6.25 Hz, 2H), 2.80 (p, J = 6.25 Hz, 2H). ), 1.23 (s, 18H). 11B NMR (96 MHz, DMSO) 6.11 (s). 13C NMR (101 MHz, DMSO) 146.7, 131.2, 123.3, 62.4, 41.4, 33.9, 31.4. Example 14: Synthesis of 2- (bis (4- (tert-butyl) phenyl) boryl) oxy) ethanamine HO, N1 2 1.477 g of a white solid are obtained from 11 mmol of 4-n-butyl -bromobenzene using Procedure A followed by Procedure C. Yield: 88% 1H NMR (400 MHz, DMSO) δ (ppm) 7.29 (d, J = 7.7 Hz, 4H), 6.95 (d, J = 7.7 Hz, 4H) ), 5.96 (bt, 2H), 3.75 (t, J = 6.4 Hz, 2H), 2.88-2.77 (p, J = 6.4 Hz, 2H), 2.58-2.42 (m, Example 13: Synthesis of 2- ((bis (4- (tert-butyl) phenyl) boryl) oxy) ethanamine O ,, H2 4H), 1.51 (dt, J = 14.9, 7.4 Hz, 4H), 1.30 (dq, J = 14.9, 7.4 Hz, 4H), 0.89 (t, J = 7.4 Hz, 6H). 11B NMR (128 MHz, DMSO) δ 5.81 (s). 13C NMR (101 MHz, DMSO) δ 148.6, 138.4, 131.5, 126.6, 62.4, 41.3, 34.8, 33.5, 21.8, 13.8. Example 15: Synthesis of 2 - ((bis (3,5-dimethylphenyl) boryl) oxy) ethanamine 1.02 g of a white solid are obtained from 11 mmol of 4-bromo-m -Xylene using procedure A followed by procedure C. Yield: 72% 1H NMR (300 MHz, DMSO) δ (ppm) 6.97 (s, 4H), 6.65 (s, 2H), 5.92 (bt, 2H), 3.70 (t, J = 6.25 Hz, 2H), 2.78 (b, J = 6.25 Hz, 2H), 2.18 (s, 12H). 11B NMR (96 MHz, DMSO) δ 5.60 (s). 13C NMR (101 MHz, DMSO) δ 134.6, 129.4, 126.3, 62.3, 41.3, 21.3. Example 16: Synthesis of 2- (dibiphenyl-4-ylboryloxy) ethanamine ## STR15 ## a white solid are obtained from 11 mmol of 4-bromobiphenyl using procedure A followed by Procedure C. Yield: 82% NMR (300 MHz, DMSO) δ 7.60 (d, J = 7.3 Hz, 4H), 7.55 (d, J = 8.0 Hz, 4H), 7.46 (d, J = 8.0 Hz) , 7.41 (d, J = 8.0 Hz, 2H), 7.30 (t, J = 7.3 Hz, 2H), 6.19 (s, 1H), 3.83 (t, J = 6.4 Hz, 2H), 2.95 - 2.83 (p, J = 6.4 Hz, 2H). 11B NMR (96 MHz, DMSO) δ 7.77 (d, J = 168.9 Hz). 13C NMR (101 MHz, DMSO) δ 151.0, 141.3, 137.0, 132.2, 128.8, 126.7, 126.4, 125.1, 62.6.41.5. Example 17 Synthesis of 2- (dibenzo [b] thiophen-5-ylboryloxy) ethanamine SS 1.337 g of a white solid are obtained from 11 mmol of 4-bromobiphenyl using Procedure A followed by Procedure C. Yield : 79% 1H NMR (300 MHz, DMSO) δ (ppm) 7.92 (s, 2H), 7.75 (d, J = 8.1 Hz, 2H), 7.55 (d, J = 5.4 Hz, 2H), 7.47 (d, J = 8.1 Hz, 2H), 7.33 (d, J = 5.4 Hz, 2H), 6.21 (bt, 2H), 3.85 (t, J = 6.4 Hz, 2H), 2.98 - 2.85 (p, J = 6.4 Hz, 2H). 11B NMR (96 MHz, DMSO) δ 6.67 (s). 13C NMR (101 MHz, DMSO) δ 147.3, 138.9, 136.4, 128.8, 126.4, 125.2, 124.0, 120.5, 62.6, 41.5.

Example 18: Synthesis of 8 - ((di-m-tolylboryl) oxy) quinoline 1.215 g of a yellow solid are obtained from 11 mmol of 3-bromotoluene using procedure A followed by procedure D. Yield: 72 NMR (300 MHz, DMSO) δ 9.11 (d, J = 5.0 Hz, 1H), 8.76 (d, J = 8.3 Hz, 1H), 7.89 (dd, J = 8.3, 5.0Hz, 1H), 7.69 ( t, J = 8.3 Hz, 1H), 7.41 (d, J = 8.3 Hz, 1H), 7.24 - 7.05 (m, 7H), 6.97 (d, J = 7.0 Hz, 2H), 2.21 (s, 6H). 11B NMR (128 MHz, DMSO) δ 12.75 (s). 13C NMR (101 MHz, DMSO) δ 157.8, 147.5, 141.3, 139.8, 136.4, 135.8, 132.3, 132.0, 128.5, 128.0, 127.2, 127.1, 124.1, 112.8, 108.6, 21.3. Example 19: Synthesis of 8 - ((di-p-tolylboryl) oxy) quinoline 1.248 g of a yellow solid are obtained from 11 mmol of 4-bromotoluene using procedure B followed by procedure D. Yield: 75 NMR (300 MHz, DMSO) δ 9.02 (d, J = 4.4 Hz, 1H), 8.75 (dd, J = 8.2, 0.6 Hz, 1H), 7.87 (dd, J = 8.2, 5.1 Hz, 1H), 7.69 (t, J = 8.2 Hz, 1H), 7.40 (d, J = 8.2 Hz, 1H), 7.23 (d, J = 7.6 Hz, 4H), 7.15 (d, J = 7.6 Hz, 1H), 7.01 ( d, J = 7.6 Hz, 4H), 2.22 (s, 6H). 11B NMR (128 MHz, DMSO) Ô 12.99 (s). 13C NMR (151 MHz, DMSO) δ 158.4, 144.6, 141.6, 140.2, 136.8, 135.8, 132.79, 132.0, 128.5, 128.4, 124.6, 113.2, 109.0, 21.3.

Example 20: Synthesis of 8 - ((bis (3-methoxyphenyl) boryboxy) minoline 1.439 g of a yellow solid are obtained from 11 mmol of 3-bromoanisole using procedure A followed by procedure D. Yield: 78 NMR (300 MHz, DMSO) δ 9.15 (d, J = 5.0 Hz, 1H), 8.78 (d, J = 8.2 Hz, 1H), 7.90 (dd, J = 8.2, 5.0 Hz, 1H), 7.71 ( t, J = 8.2 Hz, 1H), 7.43 (d, J = 8.2 Hz, 1H), 7.16 (dd, J = 15.4, 7.5 Hz, 3H), 6.94 (d, J = 7.5 Hz, 2H), 6.89 ( d, J = 2.6 Hz, 2H), 6.74 (dd, J = 8.2, 2.6 Hz, 2H), 3.66 (s, 6H) 11B NMR (128 MHz, DMSO) δ 12.67 (s) 13C NMR (101 MHz , 158.6, 157.7, 149.0, 141.4, 140.0, 136.3, 132.3, 128.4, 128.0, 124.1, 123.6, 117.2, 113.0, 111.4, 108.7, 54.6 Example 21: Synthesis of 8 - ((bis (4- methoxyphenyl) boryboxy) cminoline II 0 1.209 g of a yellow solid are obtained from 11 mmol of 4-bromoanisole using procedure A followed by procedure D. Yield: 65% 1H NMR (300 MHz, DMSO) δ 8.99 (d, J = 5.0 Hz, 1H), 8.75 (d, J = 8.2 Hz, 1H), 7 .87 (dd, J = 8.2, 5.0 Hz, 1H), 7.69 (t, J = 8.2 Hz, 1H), 7.40 (d, J = 8.2 Hz, 1H), 7.24 (d, J = 8.2 Hz, 4H). , 7.14 (d, J = 8.2 Hz, 1H), 6.78 (d, J = 8.2 Hz, 4H), 3.68 (s, 6H). 11B NMR (128 MHz, DMSO) δ 12.36 (s). 13C NMR (151 MHz, DMSO) δ 158.3, 157.9, 141.1, 139.7, 138.8, 136.3, 132.7, 132.3, 128.0, 124.0, 112.9, 112.7, 108.5, 54.7. Example 22: Synthesis of 8 - ((di (naphthalen-2-yl) boryl) oxy) quinoline 1.240 g of a yellow solid are obtained from 11 mmol of 2-bromonaphthalene using procedure B followed by procedure D Yield: 61% 1H NMR (300 MHz, DMSO) δ 9.13 (d, J = 4.9 Hz, 1H), 8.78 (d, J = 8.2 Hz, 1H), 7.90 (dd, J = 8.2, 4.9 Hz, 1H) 7.71 - 7.33 (m, 5H), 7.27 - 7.12 (m, 7H). 11B NMR (96 MHz, DMSO) δ 12.35 (s). 13C NMR (101 MHz, DMSO) δ 157.8, 147.4, 141.3, 139.9, 136.4, 132.3, 131.38, 128.0, 127.3, 126.5, 124.1, 112.9, 108.7. Example 23: Synthesis of 8 - ((diphenylboryl) oxy) quinoline 1.252 g of a yellow solid are obtained from 11 mmol of bromobenzene using procedure A followed by procedure D. Yield: 81% 1H NMR (400 MHz , DMSO) δ 9.13 (dd, J = 5.1, 0.9 Hz, 1H), 8.78 (dd, J = 8.4, 0.9 Hz, 1H), 7.90 (dd, J = 8.3, 5.1 Hz, 1H), 7.75 - 7.68 ( m, 1H), 7.43 (dd, J = 8.4, 0.5 Hz, 1H), 7.40 - 7.33 (m, 4H), 7.26 - 7.13 (m, 7H). 11B NMR (128 MHz, DMSO) δ 11.31 (s). 13C NMR (101 MHz, DMSO) δ 157.8, 141.3, 139.9, 136.4, 132.3, 131.4, 128.0, 127.3, 126.5, 124.2, 112.9, 108.7. Example 24: Synthesis of 8 - ((bis (3,4-dimethylphenyl) boryl) oxy) quinoline 1.497 g of a yellow solid are obtained from 11 mmol of 4-bromo-o-xylene using procedure A followed of procedure D. Yield: 82% 1H NMR (300 MHz, DMSO) δ 9.01 (d, J = 5.0 Hz, 1H), 8.73 (d, J = 8.2 Hz, 1H), 7.86 (dd, J = 8.2, 5.0 Hz, 1H), 7.68 (t, J = 8.2 Hz, 1H), 7.39 (d, J = 8.2 Hz, 1H), 7.14 (d, J = 7.5 Hz, 1H), 7.10 (s, 2H), 7.04 (d, J = 7.5 Hz, 2H), 6.95 (d, J = 7.5 Hz, 2H), 2.13 (s, 6H), 2.11 (s, 6H). 11B NMR (96 MHz, DMSO) δ 13.80 (s). 13C NMR (101 MHz, DMSO) δ 158.0, 144.8, 141.1, 139.6, 136.4, 134.5, 133.9, 132.8, 132.3, 129.0, 128.5, 128.0, 124.0, 112.6, 108.5, 19.5, 19.2.

Example 25: Synthesis of 8 - ((bis (4- (tert-butyl) phenyl) boryl) oxy) quinoline 1.667 g of a yellow solid are obtained from 11 mmol of 4-tert-butyl-1-bromobenzene using procedure A followed by procedure D. Yield: 79% 1H NMR (300 MHz, DMSO) δ 9.10 (d, J = 5.0 Hz, 1H), 8.76 (d, J = 8.3 Hz, 1H), 7.88 (dd, J = 8.3 , 5.0 Hz, 1H), 7.70 (t, J = 8.3 Hz, 1H), 7.41 (d, J = 8.3 Hz, 1H), 7.29 (d, J = 7.8 Hz, 4H), 7.23 (d, J = 8.3 Hz, 3H), 7.15 (d, J = 7.8 Hz, 1H), 1.22 (s, 18H). 11B NMR (128 MHz, DMSO) δ 11.50 (s). 13C NMR (101 MHz, DMSO) δ 157.9, 148.6, 144.1, 141.2, 139.7, 136.4, 132.29, 131.2, 128.0, 124.0, 112.7, 108.5, 34.0, 31.2.

Example 26: Synthesis of 8- (bis (4-butylphenyl) boryloxy) quinoline 1.532 g of a yellow solid are obtained from 11 mmol of 4-butylbromobenzene using procedure A followed by procedure D. Yield: 73% 1H NMR (300 MHz, DMSO) δ 9.07 (d, J = 4.5 Hz, 1H), 8.75 (d, J = 7.9 Hz, 1H), 7.87 (dd, J = 7.9, 4.5 Hz, 1H), 7.69 (t , J = 7.9 Hz, 1H), 7.40 (d, J = 7.9 Hz, 1H), 7.27 (d, J = 7.9 Hz, 4H), 7.15 (d, J = 7.9 Hz, 1H), 7.03 (d, J) = 7.9 Hz, 4H), 2.55-2.42 (m, 7H), 1.56-1.42 (m, 4H), 1.26 (dq, J = 14.1, 7.0 Hz, 4H), 0.85 (t, J = 7.3 Hz, 6H); .

The aryl-bonded CH2 exits in the peak of DMSO 11B NMR (128 MHz, DMSO) δ 13.45 (s). 13C NMR (101 MHz, DMSO) δ (ppm) 157.9, 144.4, 141.1, 140.3, 139.7, 136.4, 132.3, 131.4, 128.0, 127.3, 124.1, 112.7, 108.5, 34.7, 33.3, 21.8, 13.7.

Example 27: Synthesis of 8 - ((bis (3,5-dimethylphenyl) boryl) oxy) quinoline 1.043 g of a yellow solid are obtained from 11 mmol of 4-bromo-m-xylene using procedure A followed of Procedure D. Yield: 58% 1H NMR (300 MHz, DMSO) δ 9.08 (s, 1H), 8.75 (d, J = 7.6 Hz, 1H), 7.89 (s, 1H), 7.69 (s, 1H) , 7.40 (d, J = 7.6 Hz, 1H), 7.15 (d, J = 7.6 Hz, 1H), 6.94 (s, 4H), 6.77 (s, 2H), 2.16 (s, 12H). 11B NMR (128 MHz, DMSO) δ 12.72 (s). 13C NMR (101 MHz, DMSO) δ 157.9, 147.6, 141.2, 139.7, 136.4, 135.7, 132.28, 129.2, 128.0, 127.9, 124.1, 112.7, 108.6, 21.2.

Example 28: Synthesis of 8 - ((di ([1,1'-biphenyl] -4-yl) boryboxy) quinoline 1,912 g of a yellow solid are obtained from 5.5 mmol of 4-bromo-biphenyl using the procedure B followed by procedure D. Yield: 83% 1H NMR (400 MHz, DMSO) δ (ppm) 9.22 (d, J = 5.1 Hz, 1H), 8.80 (d, J = 8.3 Hz, 1H), 7.93 ( dd, J = 8.3, 5.1 Hz, 1H), 7.73 (t, J = 8.3 Hz, 1H), 7.60 (d, J = 7.4 Hz, 4H), 7.56-7.48 (m, 8H), 7.43 (dd, J). = 16.1, 8.3 Hz, 6H), 7.31 (t, J = 7.4 Hz, 2H), 7.22 (d, J = 7.4 Hz, 1H).

11B NMR (128 MHz, DMSO) δ 14.10 (s).

13C NMR (101 MHz, DMSO) δ 157.8, 146.4, 141.4, 140.7, 140.0, 138.5, 136.4, 134.8, 132.4, 132.1, 128.8, 128.1, 127.0, 126.7, 126.5, 125.8, 124.2, 113.0, 108.8. 876 mg of a white solid are obtained from 5 mmol of 4-bromotoluene (first aryl bromide) and 7.5 mmol of 4-bromoanisole (second aryl bromide) using the procedure F followed by the procedure C. Yield: 78% 1H NMR (300 MHz, DMSO) δ 7.26 (dd, J = 8.0, 2.8 Hz, 4H), 6.94 (d, J = 8.0 Hz, 2H), 6.71 (dd, J = 8.0, 1.8 Hz, 2H), 5.89 (bt, 2H), 3.74 (t, J = 6.1 Hz, 1H), 3.67 (s, 3H), 2.80 (p, J = 6.1 Hz, 1H), 2.21 (s, 3H).

11B NMR (96 MHz, DMSO) δ 5.19 (s). Example 29: Synthesis of 2 - (((4-methoxyphenyl) (p-tolyl) boryl) oxy) ethanamine / -.

Claims (10)

REVENDICATIONS1. Use of a dialkylaminoborane and at least one organometallic compound for carrying out a process for preparing a borinic acid, without formation of triorganoborane or tetraorganoborate. 2. Use according to claim 1, wherein: said dialkylaminoborane is of formula (II) below: H2B-NRR '(II) in which R and R' are identical or different groups chosen from: alkyl groups comprising 1 to 18 carbon atoms, linear, branched or cyclic, arylalkyl groups, the groups R and R 'may optionally form together an alkylene group having from 1 to 18 carbon atoms, linear or branched; Or - said borinic acid has the following formula (I): ## STR2 ## in which: n is equal to 0 or 1, X represents 0, S or C, represents a single bond when n is 1, and does not represent any bond when n is 0, - R1 and R2 are the same or different groups selected from: - alkenyl groups having 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups having from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one a substituent, - heteroaryl groups having from 2 to 12 carbon atoms, optionally bearing at least one substituent. 3. Use according to claim 1 or 2, a dialkylaminoborane, an organometallic compound of formula R1-M (Ma) and an organometallic compound of formula R2-M (Tub), in which: M represents Li , Cu, MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I, X represents 0, S or C, R1 and R2 are identical or different groups chosen from: - alkenyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryl groups containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, said optional substituents as mentioned above being chosen from halogen, in particular fluorine, chlorine, bromine or iodine, hydroxy, amino or thio groups optionally protected by "ad hoc" protecting groups, the -ORa, -NHRa, -NRaRb groups , -SRα, -000Rα, -000NHRα, -000NRaRb, -CHO, -CORα, -COOH, -CN, -COORa, -CONHRα, -CONRaRb, -CF3, -NO2, in which Ra and Rb, which are identical or different, represent alkyl groups, alkenyl, alkynyl groups, aromatic or nonaromatic cycloalkyls, cycloalkenyls, aryls, or heterocyclics containing from 1 to 18 carbon atoms, optionally bearing at least one substituent, - aldehyde groups protected in the form of acetal or of thioacetal, - ketone groups protected in the form of ketal or thioketal, - trialkylsilyl groups, - alkyl groups containing from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, - the groups alkenyls having 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - aryl groups comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryls having 2 to 12 carbon atoms, optionally bearing at least one substituent, OR - a dialkylaminoborane, and an organometallic compound of formula (IV) below: M -R 2 -X-R 1 -M (IV) in which: M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I, X represents 0, S or C, R1 and R2 are identical or different groups chosen from: - alkenyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups containing from 2 to 18 carbon atoms, linear or ra mers, optionally bearing at least one substituent, - aryl groups having from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryl groups containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, for the implementation of a process for preparing a borinic acid, without formation of triorganoborane or tetraorganoborate. A process for preparing a borinic acid or a borinic ester comprising: a step of contacting a dialkyaminoborane and at least one organometallic compound in a solvent to obtain said (dialkyamino) (diorgano) borane; , without formation of triorganoborane or tetraorganoborate, - a step of hydrolysis of said (dialkyamino) (diorgano) borane to obtain said borinic acid, and - optionally a step of contacting said borinic acid with a compound comprising a hydroxyl group to obtain said borinic ester. 5. Preparation process according to claim 4 of a borinic acid of formula (I) below: ## STR5 ## in which: n is equal to 0 or 1; X represents 0, S or C, - represents a single bond when n is 1, and represents no bond when n is 0, - R1 and R2 are identical or different groups chosen from: - alkenyl groups comprising from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups containing from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, the aryl groups comprising from 6 to 18 carbon atoms, optionally bearing at least one substituent, heteroaryl groups having from 2 to 12 carbon atoms, optionally bearing at least one substituent, said process comprising: a step of contacting, in a solvent, between: dialkyaminoborane following formula (II): H2B-NRR '(II) in which R and R' are identical or different groups chosen from: - alkyl groups containing from 1 to 18 carbon atoms, linear, branched or cyclic, - groups arylalkyls, the groups R and R 'optionally being able to form together an alkylene group comprising from 1 to 18 carbon atoms, linear or branched, and - when n is 0: o an organometallic compound of formula (Ma) below: R1 -M (Ma) in which R1 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I, and o an organometallic compound of formula ( Tub) R2-M (Tub) in which R2 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I, said setting contact with the compounds of formula (Ma) and (Tub) being simultaneous or sequential, OR - lo wherein n is 1, an organometallic compound of the following formula (IV): wherein R 2, R 1 and M are as previously defined, and wherein X is O, S; or C, to obtain said (dialkyamino) (diorgano) borane of the following formula (V): [XB NRR 'rn] R2 (y) - a step of hydrolysis of said (dialkyamino) (diorgano) borane of formula (V) to obtaining said borinic acid of formula (I) below: wherein R 1, R 2, X and n are as defined above, said contacting being inter alia between: - said dialkyaminoborane of formula H2B-NRR '(II), and - when n is 0: o said organometallic compound of formula R1-M (Ma) at a concentration of from 1.0 to 5, 0 equivalents relative to said dialkylaminoborane, and o said organometallic compound of formula R2-M (Tub), at a concentration of 1.0 to 5.0 equivalents relative to said dialkylaminoborane, or - when n is equal to 1, said organometallic compound of formula M-R2-X-R1-M (IV) at a concentration of 1.0 to 5.0 equivalents relative to said dialkylaminoborane. 6. Preparation process according to claim 5, wherein the groups R1 and R2 are identical or different groups chosen from: - aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryl groups having 2 to 12 carbon atoms, optionally bearing at least one substituent, R1 and R2, which may be identical or different, in particular representing an aryl having from 6 to 18 carbon atoms, optionally bearing at least one substituent, more particularly a phenyl optionally bearing at least one substituent. 7. Process for the preparation according to claim 5, of a borinic acid of the following formula (I): ## STR1 ## in which R 1 and R 2 are as defined in claim 5, said process comprising a step of bringing into contact, in a solvent, between: a dialkyaminoborane of formula (II) below: H2B-NRR '(II) in which R and R' are as defined in claim 5, a compound organometallic compound of formula (Ma) below: R 1 -M (Ma) in which R 1 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I; and an organometallic compound of the following formula (Tub): R2-M (Tub) in which R2 is as defined above, and M represents Li, Cu, MgX 'or ZnX', X 'representing a halogen selected in particular from Cl, Br and I, said contacting with the compounds of formula (Ma) and (Tub) being simultaneous or sequential, to obtain said (dialkyamino) (diorgano) borane of the following formula (V): R 1 B-NRR 'R 7 (y) - a step of hydrolysis of said (dialkyamino) (diorgano) borane of formula (V) to obtain said boric acid of following formula (I): ## STR1 ## in which R 1, R 2, X and n are as defined above, said contacting step being in particular: a step of bringing into simultaneous contact, in a solvent, between said dialkyaminoborane of formula H2B-NRR '(II), said organometallic compound of formula R1-M (Ma) and said organometallic compound of formula R2-M (Tub), or - a step of sequential contacting consisting of in: a first step of bringing into contact, in a solvent, between said dialkyaminoborane of formula H2B-NRR '(II) and said organometallic compound of formula R1-M (Ma), to obtain a reaction medium, and o second contacting step between said reaction medium and said organometallic compound of formula R2-M (Tub). 8. Process for the preparation according to Claim 5 of a borinic acid of the following formula (I): embedded image in which R 1, R 2 and X are as defined in claim 5 , said method comprising: - a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II) below: H2B-NRR '(II) in which R and R' are as defined in claim 5 and an organometallic compound of formula (IV) below: M-R2-X-R1-M (IV) in which R2, R1 and M are as defined above, and in which X represents 0, S or C, for obtaining said (dialkyamino) (diorgano) borane of the following formula (V): a step of hydrolyzing said (dialkyamino) (diorgano) borane of formula (V) to obtain said borinic acid of the following formula (I): embedded image in which R 1, R 2 and X are as defined above, said process being in particular a process for the preparation of a boric acid; ue of formula (Ic) following: (Ic) wherein X is as defined in claim 8, R3, R4, R5, R6, R7, R8, R9 and R10 being chosen from: halogens, in particular fluorine, chlorine, bromine or iodine, hydroxy, amino or thio groups optionally protected by "ad hoc" protecting groups, the groups -ORa, -NHRa, -NRaRb, -SRa, -000Ra, -000NHRa, -000NRaRb , -CHO, -CORa, -COOH, -CN, -COORa, -CONHRa, -CONRaRb, -CF3, -NO2, in which Ra and Rb, which may be identical or different, represent linear, branched or cycloalkylated alkyl, alkenyl or alkynyl groups, aromatic or nonaromatic cycloalkenyls, aromatic or heterocyclic having from 1 to 18 carbon atoms, optionally bearing at least one substituent, - protected aldehyde groups in the form of acetal or thioacetal, - ketone groups protected in the form of ketal or thioketal, trialkylsilyl groups, alkyl groups having from 1 to 18 carbon atoms, linear, branched or cyclic, optionally bearing at least one substituent, - alkenyl groups containing 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - alkynyl groups comprising from 2 to 18 carbon atoms, linear or branched, optionally bearing at least one substituent, - aryl groups containing from 6 to 18 carbon atoms, optionally bearing at least one substituent, - heteroaryls containing from 2 to 12 carbon atoms, optionally bearing at least one substituent, said process comprising: - a step of contacting, in a solvent, between: - a dialkyaminoborane of formula (II-1) below: H2B-NRR '(II-1) in which R and R' are as defined in claim 8, and - an organometallic compound of formula (IV-1) below: (IV-1) wherein X, R3, R4, R5, R6, R7, R8, R9, R10 and M are as defined above, for obtaining said (dialkyamino) (diorgano) borane of formula (Vc) below: (Vc), - a step of hydrolysis of said (dialkyamino) (diorgano) borane of formula (V) to obtain said borinic acid of following formula (I) (I) wherein X, R3, R4, R6, R6, R7, R8, R9 and R10 are as defined above. 9. A method of preparation according to any one of claims 5 to 8, wherein said contacting comprises an initial simultaneous contact followed by a prolonged contact, the initial contact being made especially at a temperature between from -100 ° C. to 30 ° C., in particular at about -78 ° C. or at about 20 ° C., the prolonged contact being made especially at a temperature of 0 ° C. to 90 ° C., in particular 15 ° C. ° C at 75 ° C, more preferably about 20 ° C or about 70 ° C. 10. Preparation process according to any one of claims 5 to 9, wherein M represents Li or MgX ', X' representing a halogen selected in particular from Cl, Br and I.