Method of manufacturing an organoboron salt

Abstract

The present disclosure relates to a method of manufacturing an organoboron salt, wherein the method comprises reacting an ionic boron-oxygen compound with a base and a (di)carboxylic acid, or a trimethylsilyl-protected derivative thereof, thereby forming the organoboron salt. The present disclosure also relates to a method of processing the organoboron salt.

Description

[0001] METHOD OF MANUFACTURING AN ORGANOBORON SALT

[0002] Field of the disclosure

[0003] The present disclosure relates to a method of manufacturing an organoboron salt, wherein the method comprises reacting an ionic boron-oxygen compound with a base and a (di)carboxylic acid, or a trimethylsilyl-protected derivative thereof, thereby forming the organoboron salt. The present disclosure also relates to a method of processing the organoboron salt.

[0004] Background and summary

[0005] The present disclosure relates to a method of manufacturing an organoboron salt, wherein the method comprises reacting an ionic boron-oxygen compound with a base and a (di)carboxylic acid, or a trimethylsilyl-protected derivative thereof, thereby forming the organoboron salt. The resulting organoboron salts are particularly useful as battery electrolytes and as additives, either as the pure salt or in mixtures with solvents. They can also be used as intermediates in the manufacturing of other ionic boron-oxygen compounds, such as alkali(ne earth) metal borohydrides, which are widely used as reduction agents in chemical processes. Therefore, the present disclosure also relates to a method of processing the organoboron salt.

[0006] Several methods for the manufacture of organoboron salts have been described. For example, DE 19829030 describes the manufacturing of lithium bis(oxalato) borate from boric acid. Specifically, boric acid is reacted with LiOH and oxalic acid (H2C2O4) to form the lithium bis(oxalato)borate.

[0007] US 2001 / 0033964 describes the manufacturing of tetraethylammonium bis(oxalato)borate and bis(malonato)borate from boric acid. The boric acid is reacted with oxalic acid or malonic acid, respectively, and tetraethylammonium hydroxide. Also described is a method of manufacturing of lithium bis(malonato)borate from boric acid, wherein boric acid is reacted with malonic acid and lithium carbonate.

[0008] Ge et al. (2014), Synthesis of novel organic-ligand-doped sodium bis(oxalato) borate complexes with tailored thermal stability and enhanced ion conductivity for sodium ion batteries, J. Pow. Sour, vol. 248, pgs. 77-82, also describes the manufacturing of various organoboron salts by reacting boric acid with a dicarboxylic acid and a base (NaOH). Zavalij et al. (2003), Structures of potassium, sodium and lithium bis(oxalato)borate salts from powder diffraction data, Acta Crystallogr. B., vol. 59(6), pgs. 753-759, describe the preparation of e.g. a lithium bis(oxalato) borate by reacting boric acid with oxalic acid and LiOH.

[0009] Golets et al. (2016), Understanding the thermal decomposition mechanism of a halogen-free chelated orthoborate-based ionic liquid: a combined computational and experimental study, Phys. Chem. Chem. Phys., vol. 18, pgs. 22458-22466, describe a method of manufacturing an organoboron salt, wherein boric acid is reacted with oxalic acid and Na2COs.

[0010] These methods all have in common that they use boric acid as a starting material, which is an important downside of the methods described in the literature. Boric acid is highly corrosive and so several precautions need to be taken in order to scale-up the methods described in the literature to a commercial scale. In addition, waste in the form of inorganic salts (such as sodium sulfate) is generated during the process of generating boric acid from mined borax salt and mineral acids. The latter process of generating boric acid is carried out in aqueous environment, which requires expensive and energy intensive drying steps in order to obtain boric acid. Processes using boric acid, thus, also require at least one additional process step compared to conversions starting directly from e.g. mined boron- containing material.

[0011] There is, thus, a need in the art for improved methods of manufacturing organoboron salts. Particularly, there is a need for a method of manufacturing compounds according to formula (I) that does not use boric acid as a starting material, has a broad scope, is atom- economical, can be performed under mild conditions, and results in high yields of the compounds in, ideally, substantially pure form. The present disclosure provides such a method of manufacturing.

[0012] Accordingly, in a first aspect, the disclosure relates to a method of manufacturing an organoboron salt, the method comprising: reacting an ionic boron-oxygen compound with a base and one or more (di)carboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0013] - Ri and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0014] - R1 , R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; or

[0015] - R1 and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are each independently selected from the group consisting of H, C(1-13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-

[0016] 13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; and

[0017] - X is a mono-, di-, or trivalent cation;

[0018] - when X is a monovalent cation, n is 1 ;

[0019] - when X is a divalent cation, n is 2; and

[0020] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X. The method according to the disclosure, thus, involves reacting an ionic boron-oxygen compound, such as borax or a hydrate thereof, in the presence of a base and a (di)carboxylic acid. The method according to the disclosure, thus, uses a different starting material than the methods described in the literature, which all use boric acid. Surprisingly, the method according to the disclosure affords the organoboron salt in (near) quantitative yield and / or provides direct access to organoboron salts that would otherwise be (very) difficult to obtain, as shown in the Examples. This is unexpected because reacting borax with acid, in the absence of a base, affords a completely different product: boric acid. See, e.g., Zarenehad & Garside (2008), Crystallization of boric acid through reactive dissolution of oxalic acid crystals in aqueous borax solution, Dev. Chem. Eng. Miner. Process., vol. 11 , issue 5-6, pgs. 603-620.

[0021] In a further aspect, the disclosure relates to a method of processing an organoboron salt, wherein the method comprises the steps of: manufacturing an organoboron salt, wherein the organoboron salt is a compound according to formula (I), according to the method of manufacturing an organoboron salt according to the disclosure, and reacting the organoboron salt with a further reagent.

[0022] In the method of processing the organoboron salt disclosed herein, the compound according to formula (I) is converted into a different product using the further reagent. For example, the compound according to formula (I) can be reacted with a hydride source, such as NaH, to form sodium borohydride, transesterified with an alcohol, a diol, or a different dicarbonic acid or a salt thereof to form different organoboron salts that can be used as, e.g., electrolytes. As another example, the compound according to formula (I) can be reacted with an ammonium salt or a phosphonium salt to exchange the cation X for e.g. an ammonium cation or a phosphonium cation, respectively.

[0023] Khatri et al.: “Halogen-free ammonium-organoborate ionic liquids as lubricating additivies: the effect of alkyl chain lengths on the tribological performance”, New Journal of Chemistry, vol. 40, no. 6, 1 January 2016, pgs. 5294-5299 describes the effect of variation in alkyl chain length or the number of CH2 groups (from 1 to 4) in chelated orthoborate anion containing ionic liquids having the tetrabutylammonium cation on their tribological properties.

[0024] KR 2019 0096154 describes a method of synthesising lithium bisoxalatoborate. The method generally uses boric acid as a starting material. Kibbel: “Uber tetraacetatoborate”, Zeitschrift fur Chemie, vol. 5, no. 11, 1 November 1965, pgs. 425-426 describes a synthesis of Me[B(OAc4], wherein Me is K, Rb, Cs, or Ti. The synthesis uses B2O(OAc)4 as a starting material.

[0025] CN 101 643481 describes a preparation of electrolyte salts used in lithium ion batteries, in particular a synthetic process capable of simultaneously obtaining lithium difluorooxalate borate and lithium bisoxalate borate.

[0026] Detailed description

[0027] The disclosure is described in detail below. As will be evident to the skilled person, different embodiments of the present disclosure can be combined unless they are mutually exclusive.

[0028] When amounts, concentrations, dimensions and other parameters are expressed in the form of a range, a preferable range, an upper limit value, a lower limit value or preferable upper and limit values, it should be understood that any ranges obtainable by combining any upper limit or preferable value with any lower limit or preferable value are also specifically disclosed, irrespective of whether the obtained ranges are clearly mentioned in the context.

[0029] Method of manufacturing the compound according to formula (I)

[0030] As mentioned, disclosed herein is a method of manufacturing an organoboron salt, the method comprising reacting an ionic boron-oxygen compound with a base and one or more (di)carboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein: - Ri and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0031] - R1 , R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; or

[0032] - R1 and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are each independently selected from the group consisting of H, C(1-13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-

[0033] 13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; and

[0034] - X is a mono-, di-, or trivalent cation;

[0035] - when X is a monovalent cation, n is 1 ;

[0036] - when X is a divalent cation, n is 2; and

[0037] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

[0038] In particular embodiments, the method of manufacturing an organoboron salt may comprise the steps of reacting an ionic boron-oxygen compound with a base and one or more (di)carboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0039] - Ri and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0040] - R1 , R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; and

[0041] - X is a mono-, di-, or trivalent cation;

[0042] - when X is a monovalent cation, n is 1;

[0043] - when X is a divalent cation, n is 2; and

[0044] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

[0045] The method comprises a step of reacting an ionic boron-oxygen compound with a base and one or more (di)carboxylic acids or trimethylsilyl-protected derivatives thereof in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound.

[0046] The ionic boron-oxygen compound used in the method according to the disclosure may be any ionic boron-oxygen compound. The ionic boron-oxygen compound may be an inorganic boron-oxygen compound. For example, the ionic boron-oxygen compound may be a boron- oxygen-compound-containing mineral. The ionic boron-oxygen compound may be present in a boron-containing waste material, such as mixtures comprising salts of BO2; salts of B3C>3(OH)4', salts of B4O5(OH)42-, salts of B3O3(OH)s2', and / or salts of B(OH)4‘, and optionally one or more solvents. Non-limiting examples of salts of BC>2' are NaBCh, Li BO2, KBO2, Ca(BC>2)2, and Mg(BC>2)2. Non-limiting examples of salts of B3O3(OH)4' are NaB3O3(OH)4, LiB3C>3(OH)4, and KB3O3(OH)4. Non-limiting examples of salts of B4Os(OH)42' are NaB4Os(OH)4, LiB4Os(OH)4, and KB4Os(OH)4. Non-limiting examples of salts of B3O3(OH)s2' are NaB3O3(OH)s, LiB3O3(OH)s, and KB3O3(OH)s. Non-limiting examples of salts of B(OH)4‘ are NaB(OH)4, LiB(OH)4, KB(OH)4, Ca[B(OH)4]2, and Mg[B(OH)4]2. Accordingly, the ionic boron-oxygen compound may be selected from one or more of the group consisting of borax or a hydrate thereof, colemanite, meyerhofferite, inyoite, pandermite, inderite, boracite, salts of BO2; salts of B3C>3(OH)4', salts of B4Os(OH)42', salts of B3O3(OH)s2', and salts of B(OH)4‘.

[0047] In preferred embodiments, the ionic boron-oxygen compound is a mineral. The ionic boron- oxygen compound may, for example, be:

[0048] - a compound according to formula (Ila), ZpBqOr(OH)s, or a hydrate thereof, wherein: Z is Li, Na, or K; p is 1 or 2; q is from 2 to 10; r is from 2 to 13; and s is from 0 to 10, provided that p + 3q = 2r + s and / or

[0049] - a compound according to formula (lib), ZpBqOr(OH)s, or a hydrate thereof, wherein: Z is Mg or Ca; p is 2 or 3; q is from 5 to 10; r is from 5 to 13; and s is from 0 to 5, provided that 2p + 3q = 2r + s.

[0050] The boron-oxygen compound may be one or more selected from the group consisting of borax and hydrates thereof (in particular, borax, kernite, tincalconite, and tincal), colemanite, meyerhofferite, inyoite, pandermite, inderite, and boracite. Of these ionic boron-oxygen compounds, borax, kernite, tincalconite, and tincal may be preferred due to their good availability in nature.

[0051] The ionic boron-oxygen compound may also be present in a boron-containing waste material. Accordingly, the ionic boron-oxygen compound may be provided as a boron- containing waste material comprising the ionic boron-oxygen compound, optionally wherein the ionic boron-oxygen compound is a salt of BO2; a salt of B3O3(OH)4', a salt of B4Os(OH)42', a salt of B3C>3(OH)52', and / or a salt of B(OH)4‘. Examples of suitable boron-containing waste materials are described in WO 2004 / 101431.

[0052] The ionic boron-oxygen compound may be dehydrated prior to reacting it with the base and (di)carboxylic acid, or a trimethylsilyl-protected derivative thereof, but this is not necessary. It may be preferred that, in the method of manufacturing the organoboron salt, the ionic boronoxygen compound is not dehydrated, in particular if the ionic boron-oxygen compound is provided as a boron-containing waste product comprising the ionic boron-oxygen compound, such as discharged fuel solution from a hydrogen generating apparatus.

[0053] The base used in the method according to the disclosure may be a hydroxide salt, such as a hydroxide of an alkali metal or a hydroxide of an alkaline earth metal, a carbonate salt, a bicarbonate salt, an oxide of an alkali metal, and / or an oxide of an alkaline earth metal. Examples of suitable bases are bases selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, LiHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO. When selecting a base, it is advantageous for the alkali metal(s) and / or the alkaline earth metal(s) present in the ionic boron-oxygen compound to be the same as the alkali metal(s) and / or the alkaline earth metal(s) present in the base. For example, if the ionic boron-oxygen compound is borax, kernite, tincalconite or tincal, the base is preferably NaOH, Na2CO3, NaHCO3, or Na2O. As another example, if the ionic boron-oxygen compound is colemanite, meyerhofferite, inyoite or pandermite, the base is preferably Ca(OH)2, CaCO3, Ca(HCO3)2, or CaO. As yet another example, if the ionic boron-oxygen compound is inderite or boracite, the base is preferably Mg(OH)2, MgCO3, Mg(HCO3)2, or MgO. Accordingly, the ionic boron-oxygen compound and the base comprise a cation, wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same (as X).

[0054] The reacting may comprise using at least 0.5 mole of base per mole of cation in the total of the ionic boron-oxygen compound. For example, the reacting may comprise using from 0.5 to 5.0 moles of base per mole of cation in the total of the ionic boron-oxygen compound, in particular from 1 .0 to 3.0 moles of base per mole of cation, more in particular about 2.0 moles of base per mole of cation. For example, borax (Na2B4C>7) comprises two moles of sodium cations per mole of borax, which means the reacting may comprise using two moles of base (e.g. NaOH).

[0055] The reacting comprises using the one or more (di)carboxylic acids or trimethylsilyl-protected derivatives thereof in a total amount of at least 2.0 moles of (di)carboxylic acid or trimethylsilyl-protected derivative thereof per mole of boron in the total of the ionic boron- oxygen compound.

[0056] It is within the scope of the skilled person’s abilities to select the appropriate (di)carboxylic acid(s) and amount(s) of the (di)carboxylic acid(s) or trimethylsilyl-protected derivatives thereof, depending on the organoboron salt that is manufactured. For example, if the skilled person were to manufacture sodium bis(oxalato)borate from tincal, the skilled person would understand that it is desirable to use at least 8 equiv. of oxalic acid.

[0057] Suitable monocarboxylic acids for use in the method of manufacturing the organoboron salt include, but are not limited to, formic acid, acetic acid, acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, benzoic acid, salicylic acid, gallic acid, 1-naphtoic acid, trifluoroacetic acid, perfluoropropanoic acid, perfluorobutanoic acid, perfluoropentanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorotetradecanoic acid, pentafluorobenzoic acid, isobutyric acid, isovaleric acid, acrylic acid, and methacrylic acid.

[0058] Suitable dicarboxylic acids for use in the method of manufacturing the organoboron salt include, but are not limited to, oxalic acid, malonic acid, succinic acid, 2-fluormalonic acid, 2- methyl-2-fluormalonic acid, 2,2-dimethylmalonic acid, and prop-2-enylmalonic acid.

[0059] The (di)carboxylic acids can be added as trimethylsilyl-protected (di)carboxylic acids. For example, (trimethylsilyl)acetic acid can be instead of acetic acid and bis(trimethylsilyl)oxalate can be added instead of oxalic acid. However, it is preferred that the (di)carboxylic acids are added in their free acid form.

[0060] It is desirable to use at least 2.0 moles of dicarboxylic acid or trimethylsilyl-protected derivative thereof per mole of boron in the total of the ionic boron-oxygen compound when the organoboron salt is a compound comprising two fused rings. It may be preferred that the reacting comprises using one or more dicarboxylic acids or trimethylsilyl-protected derivatives thereof in a total amount of from 2.0 to 10 moles of dicarboxylic acid or trimethylsilyl-protected derivative thereof per mole of boron in the total of the ionic boronoxygen compound, in particular a total amount of from 2.0 to 7.0 moles of dicarboxylic acid or trimethylsilyl-protected derivative thereof per mole of boron in the total of the ionic boronoxygen compound, more in particular 2.0 to 2.3 moles of dicarboxylic acid or trimethylsilyl- protected derivative thereof per mole of boron in the total of the ionic boron-oxygen compound. It is desirable to use at least 4.0 moles of dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound when the organoboron salt is a compound comprising four coordinated (di)carboxylic acids. It may be preferred that the reacting comprises using one or more (di)carboxylic acids or trimethylsilyl-protected derivatives thereof in a total amount of from 4.0 to 10 moles of (di)carboxylic acid or trimethylsilyl-protected derivative thereof per mole of boron in the total of the ionic boron-oxygen compound, in particular a total amount of from 4.0 to 7.0 moles of (di)carboxylic acid or trimethylsilyl-protected derivative thereof per mole of boron in the total of the ionic boron-oxygen compound, more in particular 4.0 to 4.3 moles of (di)carboxylic acid or trimethylsilyl-protected derivative thereof per mole of boron in the total of the ionic boron-oxygen compound.

[0061] The reacting preferably comprises using the base and the (di)carboxylic acid, or the trimethylsilyl-protected derivative thereof, in at least a stoichiometric amount. It is particularly preferred that the reacting comprises using the base and the (di)carboxylic acid, or the trimethylsilyl-protected derivative thereof, in a stoichiometric amount, as this results in a completely atom economical process and, thus, an essentially pure product when an ionic boron-oxygen-containing mineral is used as the ionic boron-oxygen compound. It is well within the capabilities of the skilled person to determine what is a stoichiometric amount by balancing the chemical equation and then determining appropriate amounts of reagent.

[0062] As an example, the stoichiometric amounts of particular bases and dicarboxylic acids have been listed below for a number of ionic boron-oxygen compounds.

[0063] *Equivalents as defined in this Table refer to the number of molar equivalents compared to 1 equiv. of the ionic boron-oxygen compound.

[0064] The reacting may be done in the presence of solvent. The solvent may be water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1- 5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy- C(5-6)cycloalkyl, 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof. Water is a preferred solvent. Accordingly, the solvent preferably comprises water. When a mixture of organic solvent and water is used, the organic solvent and the water may be added in a volume ratio of from 10: 1 to 1 : 10, in particular a volume ratio of from 5: 1 to 1 :5, more in particular a volume ratio of from 3:1 to 1 :3, such as a volume ratio of about 1:1.

[0065] The reacting may be carried out at a temperature of at least 20 °C. The reacting may preferably be carried out at a temperature of from 20 °C to the reflux temperature of a solvent, optionally wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1- 8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro- C(1-4)alkyl, or a mixture thereof. Temperatures higher than reflux temperature are undesirable, because they can only be achieved with a complex process.

[0066] The reacting may be carried out under any atmosphere. It may be preferred for the reacting to be carried out under air or under an inert atmosphere (e.g. a nitrogen atmosphere or argon atmosphere).

[0067] The method according to the disclosure may be carried out under atmospheric pressure or under elevated pressure. For example, the reacting may be carried out under a pressure of 1.1 bar or more, such as a pressure of 1.5 bar or more. It is, however, preferred that the reacting is carried out under atmospheric pressure (1.0 bar). The reactants (i.e. , the ionic boron-oxygen compound, the base and the (di)carboxylic acid, or the trimethylsilyl-protected derivative thereof) may be added at the same time or sequentially.

[0068] The method results in the manufacture of the compound according to formula (I). The compound according to formula (I) comprises a monovalent, divalent, or trivalent cation: X. As will be explained in more detail below, it is particularly preferred that the monovalent, divalent, or trivalent cation X originates from the ionic boron-oxygen compound and from the base.

[0069] The compound according to formula (I) also comprises two or more coordinating groups that correspond to the (di)carboxylic acids that reacted with the ionic boron-oxygen compound. Depending on the amount and type of (di)carboxylic acid, or trimethylsilyl-protected derivatives thereof, added, the ionic boron-oxygen compound can be converted into one of three kinds of organoboron salts: an organoboron salt having two fused rings, an organoboron salt having one fused ring and two coordinated (di)carboxylic acids, or an organoboron salt having four coordinated (di)carboxylic acids. The specific embodiments below illustrate this.

[0070] Organoboron salts having two fused rings

[0071] In particular embodiments, disclosed herein is a method of manufacturing an organoboron salt, the method comprising: reacting an ionic boron-oxygen compound with a base (in particular, a base is selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2COs, K2CO3, U2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, LiHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, U2O, CaO, and MgO) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0072] - Ri and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen; and

[0073] - X is a mono-, di-, or trivalent cation;

[0074] - when X is a monovalent cation, n is 1;

[0075] - when X is a divalent cation, n is 2; and

[0076] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0077] In these embodiments, the compound according to formula (I) may be a compound according to formula (la), wherein:

[0078] - Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0079] - X is a mono-, di-, or trivalent cation;

[0080] - when X is a monovalent cation, n is 1 ;

[0081] - when X is a divalent cation, n is 2;

[0082] - when X is a trivalent cation, n is 3; and

[0083] - each m is independently 0, 1 , or 2 (in particular each m is independently 0 or 1 , more in particular both m are 0 or 1); and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein Rs and R7 are the same, optionally wherein Rs and Rs are the same, optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0084] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound with a base selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, LiHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of cation in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (la), wherein:

[0085] - Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0086] - X is a mono-, di-, or trivalent cation;

[0087] - when X is a monovalent cation, n is 1 ;

[0088] - when X is a divalent cation, n is 2;

[0089] - when X is a trivalent cation, n is 3;

[0090] - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1); and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein each m is the same, optionally wherein R5 and R7 are the same, optionally wherein Re and Rs are the same, optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof. In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of borax, kernite, tincalconite, tincal, colemanite, meyerhofferite, inyoite, pandermite, inderite, boracite, and hydrates thereof with a base selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, LiHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of cation in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (la), wherein:

[0091] - Rs, Re, R?, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0092] - X is a mono-, di-, or trivalent cation;

[0093] - when X is a monovalent cation, n is 1 ;

[0094] - when X is a divalent cation, n is 2; and

[0095] - when X is a trivalent cation, n is 3;

[0096] - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1); and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein each m is the same, optionally wherein R5 and R7 are the same, optionally wherein Re and Rs are the same, optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0097] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of borax and hydrates thereof (in particular borax, kernite, tincalconite, and tincal) with a base selected from the group consisting of NaOH, Na2COs, NaHCOs, and Na2O (optionally, in a total amount of at least 1.0 moles of base per mole of sodium in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (la), wherein:

[0098] - Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0099] - X is Na;

[0100] - n is 1 ; and - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1), optionally wherein each m is the same, optionally wherein Rs and R? are the same, optionally wherein Rs and Rs are the same, optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0101] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of colemanite, meyerhofferite, inyoite, pandermite, and hydrates thereof with a base selected from the group consisting of Ca(OH)2, CaCOs, Ca(HCC>3)2, and CaO (optionally, in a total amount of at least 1.0 moles of base per mole of calcium in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (la), wherein:

[0102] - Rs, Re, R?, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0103] - X is Ca; - n is 2; and

[0104] - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1), optionally wherein each m is the same, optionally wherein R5 and R7 are the same, optionally wherein Re and Rs are the same, optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0105] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of inderite, boracite, and hydrates thereof with a base selected from the group consisting of Mg(OH)2, MgCOs, Mg(HCOs)2, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of magnesium in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 (in particular, from 2.0 to 5.0) moles of the dicarboxylic acid or trimethylsilyl- protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (la), wherein:

[0106] - Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0107] - X is Mg; - n is 2; and

[0108] - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1), optionally wherein each m is the same, optionally wherein Rs and R? are the same, optionally wherein Rs and Rs are the same, optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0109] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting (an boron-containing waste material comprising) an ionic boron-oxygen compound selected from one or more of the group consisting of salts of BO2', salts of BsC OH , salts of B4O5(OH)42-, salts of B3C>3(OH)52', and salts of B(OH)4' with a base selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, UHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of cation in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (la), wherein: - Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0110] - X is a mono-, di-, or trivalent cation,;

[0111] - when X is a monovalent cation, n is 1 ;

[0112] - when X is a divalent cation, n is 2; and

[0113] - when X is a trivalent cation, n is 3; and

[0114] - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1); and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein each m is the same, optionally wherein Rs and R7 are the same, optionally wherein Rs and Rs are the same, optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0115] In the above embodiments, the organoboron salt may be a compound according to formula (la), wherein:

[0116] - Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen; - X is Na, Li, or K;

[0117] - n is 1 ; and

[0118] - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1).

[0119] In the above embodiments, the organoboron salt may be a compound according to formula (la), wherein:

[0120] - Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;

[0121] - X is Ca or Mg;

[0122] - n is 2; and

[0123] - each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1).

[0124] In some of the above embodiments, Rs and R7 are the same, Rs and Rs are the same, and each m is the same. As the skilled person would understand, this means that the boron atom is coordinated to two identical dicarboxylic acids.

[0125] Non-limiting examples of compounds according to formula (la) are Na-[B(OC(=O)-C(=O)O)2], Na-[B(OC(=O)-CH2-C(=O)O)2], Na-[B(OC(=O)-CHF-C(=O)O)2], Na-[B(OC(=O)-C(CH3)F- C(=O)O)2], Na-[B(OC(=O)-C(CH3)2-C(=O)O)2], Na-[B(OC(=O)-CH(CH2CHCH2)-C(=O)O)2], and Na-[B(OC(=O)-CH2-CH2-C(=O)O)2]. For the avoidance of doubt, it is noted that Na- [B(OC(=O)-C(=O)O)2] refers bis(oxalato) borate, wherein ‘OC(=O)-C(=O)O’ refers to the chemical structure of oxalate (minus two hydrogen atoms, because both carboxylic acids coordinate to the boron atom).

[0126] Further non-limiting examples of compounds according to formula (la) are Li-[B(OC(=O)-

[0127] C(=O)O)2], Li-[B(OC(=O)-CH2-C(=O)O)2], Li-[B(OC(=O)-CHF-C(=O)O)2], Li-[B(OC(=O)- C(CH3)F-C(=O)O)2], Li-[B(OC(=O)-C(CH3)2-C(=O)O)2], Li-[B(OC(=O)-CH(CH2CHCH2)-

[0128] C(=O)O)2], and Li-[B(OC(=O)-CH2-CH2-C(=O)O)2],

[0129] Further non-limiting examples of compounds according to formula (la) are K-[B(OC(=O)-

[0130] C(=O)O)2], K-[B(OC(=O)-CH2-C(=O)O)2], K-[B(OC(=O)-CHF-C(=O)O)2], K-[B(OC(=O)-

[0131] C(CH3)F-C(=O)O)2], K-[B(OC(=O)-C(CH3)2-C(=O)O)2], K-[B(OC(=O)-CH(CH2CHCH2)- C(=O)O)2], and K-[B(OC(=O)-CH2-CH2-C(=O)O)2],

[0132] Further non-limiting examples of compounds according to formula (la) are NH4-[B(OC(=O)-

[0133] C(=O)O)2], NH4-[B(OC(=O)-CH2-C(=O)O)2], NH4-[B(OC(=O)-CHF-C(=O)O)2], NH4- [B(OC(=O)-C(CH3)F-C(=O)O)2], NH4-[B(OC(=O)-C(CH3)2-C(=O)O)2], NH4-[B(OC(=O)-

[0134] CH(CH2CHCH2)-C(=O)O)2], and NH4-[B(OC(=O)-CH2-CH2-C(=O)O)2],

[0135] Further non-limiting examples of compounds according to formula (la) are N(C(1-4)alkyl)4- [B(OC(=O)-C(=O)O)2], N(C(1-4)alkyl)4-[B(OC(=O)-CH2-C(=O)O)2], N(C(1-4)alkyl)4-

[0136] [B(OC(=O)-CHF-C(=O)O)2], N(C(1-4)alkyl)4-[B(OC(=O)-C(CH3)F-C(=O)O)2], N(C(1-4)alkyl)4-

[0137] [B(OC(=O)-C(CH3)2-C(=O)O)2], N(C(1-4)alkyl)4-[B(OC(=O)-CH(CH2CHCH2)-C(=O)O)2], and

[0138] N(C(1-4)alkyl)4-[B(OC(=O)-CH2-CH2-C(=O)O)2],

[0139] Organoboron salts having one fused ring

[0140] In some embodiments, a method of manufacturing an organoboron salt comprises the steps of: reacting an ionic boron-oxygen compound with a base and one or more (di)carboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0141] - Ri and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen,

[0142] - R3 and R4 are each independently selected from the group consisting of H, C(1- 13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6- 10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; and

[0143] - X is a mono-, di-, or trivalent cation;

[0144] - when X is a monovalent cation, n is 1 ;

[0145] - when X is a divalent cation, n is 2; and

[0146] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

[0147] In these embodiments, the compound according to formula I may be a compound, wherein

[0148] - R1 and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen;

[0149] - R3 and R4 are each independently selected from the group consisting of C(1- 13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-13)alkyl, C(2-8)alkenyl, and C(6- 10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0150] - X is a mono-, di-, or trivalent cation;

[0151] - when X is a monovalent cation, n is 1 ;

[0152] - when X is a divalent cation, n is 2; and

[0153] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

[0154] More particularly, the compound according to formula I may also be a compound, wherein

[0155] - R1 and R2 are fused and form a five- or six-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen;

[0156] - R3 and R4 are each independently selected from the group consisting of H, C(1- 13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-13)alkyl, C(2-8)alkenyl, and C(6- 10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0157] - X is a mono-, di-, or trivalent cation;

[0158] - when X is a monovalent cation, n is 1;

[0159] - when X is a divalent cation, n is 2; and

[0160] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

[0161] For example, the compound according to formula I may also be a compound, wherein

[0162] - R1 and R2 are fused and form a five- or six-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen;

[0163] - R3 and R4 are each independently selected from the group consisting of H, C(1- 13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-14)alkyl, C(2-8)alkenyl, and C(6- 10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0164] - X is a metal ion selected from the group consisting of Na, Li, and K;

[0165] - n is 1.

[0166] As another example, the compound according to formula I may also be a compound, wherein

[0167] - R1 and R2 are fused and form a five- or six-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen;

[0168] - R3 and R4 are each independently selected from the group consisting of H, C(1- 13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-14)alkyl, C(2-8)alkenyl, and C(6- 10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0169] - X is a metal ion selected from the group consisting of Ca and Mg;

[0170] - n is 2. Non-limiting examples of compounds according to these embodiments are Xn+-[B(OC(=O)- C(=O)O)(OC(=O)H)2]n, Xn+-[B(OC(=O)-C(=O)O)(OC(=O)-(CH3)2]n, Xn+-[B(OC(=O)- C(=O)O)(OC(=O)-(CH2CH3)2]n, Xn+-[B(OC(=O)-C(=O)O)(OC(=O)-(CH2CH2CH3)2]n,Xn+- [B(OC(=O)-C(=O)O)(OC(=O)-(CH2CH2CH2CH3)2]n, Xn+-[B(OC(=O)-C(=O)O)(C6H5)2]n, Xn+- [B(OC(=O)-C(=O)O)(C6F5)2]n, Xn+-[B(OC(=0)-C(=0)0)(CioH7)2]n, Xn+-[B(OC(=O)-CH2- C(=O)O)(OC(=O)-(CH3)2]n, Xn+-[B(OC(=O)-CH2-C(=O)O)(OC(=O)-(CH2CH3)2]n, Xn+- [B(OC(=O)-CH2-C(=O)O)(OC(=O)-(CH2CH2CH3)2]n,Xn+-[B(OC(=O)-CH2-C(=O)O)- (CH2CH2CH2CH3)2]n, Xn+-[B(OC(=O)-CH2-C(=O)O)(C6H5)2]n, Xn+-[B(OC(=O)-CH2- C(=O)O)(C6F5)2]n, and Xn+-[B(OC(=O)-CH2-C(=O)O)(C H7)2]n, wherein X is selected from the group consisting of Na, Li, K, Ca, and Mg and, when X is Na, Li or K, n is 1 , and when X is Ca or Mg, n is 2.

[0171] Organoboron salts having no fused rings

[0172] The method of manufacturing an organoboron salt may be a method comprising reacting an ionic boron-oxygen compound with a base and one or more (di)carboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0173] - Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; and

[0174] - X is a mono-, di-, or trivalent cation;

[0175] - when X is a monovalent cation, n is 1 ; - when X is a divalent cation, n is 2; and

[0176] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

[0177] In particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound with a base selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, LiHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of cation in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0178] - Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0179] - X is a mono-, di-, or trivalent cation;

[0180] - when X is a monovalent cation, n is 1 ;

[0181] - when X is a divalent cation, n is 2; and

[0182] - when X is a trivalent cation, n is 3, and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0183] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of borax, kernite, tincalconite, tincal, colemanite, meyerhofferite, inyoite, pandermite, inderite, boracite, and hydrates thereof with a base selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, LiHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of cation in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0184] - Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0185] - X is a mono-, di-, or trivalent cation;

[0186] - when X is a monovalent cation, n is 1;

[0187] - when X is a divalent cation, n is 2;

[0188] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0189] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of borax and hydrates thereof (in particular borax, kernite, tincalconite, and tincal) with a base selected from the group consisting of NaOH, Na2COs, NaHCCh, and Na2O (optionally, in a total amount of at least 1.0 moles of base per mole of sodium in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0190] - Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0191] - X is Na; and

[0192] - n is 1 ; optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0193] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of colemanite, meyerhofferite, inyoite, pandermite, and hydrates thereof with a base selected from the group consisting of Ca(OH)2, CaCCh, Ca(HCC>3)2, and CaO (optionally, in a total amount of at least 1.0 moles of base per mole of calcium in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein: - R1 , R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0194] - X is Ca; and

[0195] - n is 2; optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0196] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of inderite, boracite, and hydrates thereof with a base selected from the group consisting of Mg(OH)2, MgCCh, Mg(HCC>3)2, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of magnesium in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 (in particular, from 2.0 to 5.0) moles of the dicarboxylic acid or trimethylsilyl- protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0197] - Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0198] - X is Mg; and

[0199] - n is 2; optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0200] In more particular embodiments, the method of manufacturing an organoboron salt disclosed herein comprises: reacting an boron-containing waste material comprising an ionic boron-oxygen compound selected from one or more of the group consisting of salts of BO2', salts of B3O3(OH)4_, salts of B4O5(OH)42-, salts of B3C>3(OH)52', and salts of B(OH)4' with a base selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, UHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO (optionally, in a total amount of at least 1.0 moles of base per mole of cation in the ionic boron-oxygen compound) and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I), wherein:

[0201] - R1, R2, R3, and R4are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0202] - X is a mono-, di-, or trivalent cation;

[0203] - when X is a monovalent cation, n is 1 ;

[0204] - when X is a divalent cation, n is 2;

[0205] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X; optionally wherein the reacting is carried out in the presence of a solvent, in particular wherein the solvent is water, a nitrile (in particular, acetonitrile), a C(1-8)alcohol (optionally a C(3-8)alcohol), a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetrahydrofuran, 2- methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof.

[0206] In each of the above embodiments, the organoboron salt may be a compound according to formula (I), wherein:

[0207] - Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0208] - X is a mono-, di-, or trivalent cation;

[0209] - when X is a monovalent cation, n is 1 ;

[0210] - when X is a divalent cation, n is 2; and

[0211] - when X is a trivalent cation, n is 3; and wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

[0212] For example, the organoboron salt may be a compound according to formula (I), wherein:

[0213] - Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;

[0214] - X is a metal ion selected from the group consisting of Na, Li, and K; and

[0215] - n is 1.

[0216] As another example, the organoboron salt may be a compound according to formula (I), wherein:

[0217] - R1 , R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; - X is a metal ion selected from the group consisting of Ca and Mg; and

[0218] - n is 2.

[0219] In each of the above embodiments, Ri to R4 may be the same. This is advantageous, because the organoboron salt will then be a pure compound. That, in turn, makes the further processing of the organoboron salt more straightforward. However, R1 to R4 need not be the same. Each of R1 to R4 may each be different. Alternatively, two or three of R1 to R4 may be different. The skilled person would understand that the exact nature of the organoboron salt depends on the nature and the amount of the (di)carboxylic acid(s) added.

[0220] Non-limiting examples of compounds according to formula (I) are Na-[B(OC(=O)H)4], Na- [B(OC(=O)CH3)4], Na-[B(OC(=O)CH2CH3)4], Na-[B(OC(=O)CH2CH2CH3)4], Na- [B(OC(=O)CH2CH2CH2CH3)4], Na-[B(OC(=O)CH(OH)(CH3))4], Na-[B(OC(=O)C(=O)OH)4], Na-[B(OC(=O)CH2C(=O)OH)4], Na-[B(OC(=O)CHFC(=O)OH)4], Na- [B(OC(=O)CH2CH2C(=O)OH)4], Na-[B(OC(=O)-C6H5)4], Na-[B(OC(=O)-C6F5)4], and Na- [B(OC(=0)-CIOH7)4].

[0221] Further non-limiting examples of compounds according to formula (I) are Li-[B(OC(=O)H)4], Li-[B(OC(=O)CH3)4], Li-[B(OC(=O)CH2CH3)4], Li-[B(OC(=O)CH2CH2CH3)4], Li- [B(OC(=O)CH2CH2CH2CH3)4], Li-[B(OC(=O)CH(OH)(CH3))4], Li-[B(OC(=O)C(=O)OH)4], Li- [B(OC(=O)CH2C(=O)OH)4], Li-[B(OC(=O)CHFC(=O)OH)4], Li-[B(OC(=O)CH2CH2C(=O)OH)4], Li-[B(OC(=O)-C6H5)4], Li-[B(OC(=O)-C6F5)4], and Li-[B(OC(=O)-Ci0H7)4].

[0222] Further non-limiting examples of compounds according to formula (I) are K-[B(OC(=O)H)4], K-[B(OC(=O)CH3)4], K-[B(OC(=O)CH2CH3)4], K-[B(OC(=O)CH2CH2CH3)4], K- [B(OC(=O)CH2CH2CH2CH3)4], K-[B(OC(=O)CH(OH)(CH3))4], K-[B(OC(=O)C(=O)OH)4], K- [B(OC(=O)CH2C(=O)OH)4], K-[B(OC(=O)CHFC(=O)OH)4], K-[B(OC(=O)CH2CH2C(=O)OH)4], K-[B(OC(=O)-C6H5)4], K-[B(OC(=O)-C6F5)4], and K-[B(OC(=O)-CI0H7)4].

[0223] Further non-limiting examples of compounds according to formula (I) are NH4-[B(OC(=O)H)4], NH4-[B(OC(=O)CH3)4], NH4-[B(OC(=O)CH2CH3)4], NH4-[B(OC(=O)CH2CH2CH3)4], NH4- [B(OC(=O)CH2CH2CH2CH3)4], NH4-[B(OC(=O)CH(OH)(CH3))4], NH4-[B(OC(=O)C(=O)OH)4], NH4-[B(OC(=O)CH2C(=O)OH)4], NH4-[B(OC(=O)CHFC(=O)OH)4], NH4- [B(OC(=O)CH2CH2C(=O)OH)4], NH4-[B(OC(=O)-C6H5)4], NH4-[B(OC(=O)-C6F5)4], and NH4- [B(OC(=0)-CIOH7)4]. Further non-limiting examples of compounds according to formula (I) are N(C(1-4)alkyl)4- [B(OC(=O)H)4], N(C(1-4)alkyl)4-[B(OC(=O)CH3)4], N(C(1-4)alkyl)4-[B(OC(=O)CH2CH3)4], N(C(1-4)alkyl)4-[B(OC(=O)CH2CH2CH3)4], N(C(1-4)alkyl)4-[B(OC(=O)CH2CH2CH2CH3)4], N(C(1-4)alkyl)4-[B(OC(=O)CH(OH)(CH3))4], N(C(1-4)alkyl)4-[B(OC(=O)C(=O)OH)4], N(C(1- 4)alkyl)4-[B(OC(=O)CH2C(=O)OH)4], N(C(1-4)alkyl)4-[B(OC(=O)CHFC(=O)OH)4], N(C(1- 4)alkyl)4-[B(OC(=O)CH2CH2C(=O)OH)4], N(C(1-4)alkyl)4-[B(OC(=O)-C6H5)4], N(C(1-4)alkyl)4- [B(OC(=O)-C6F5)4], and N(C(1-4)alkyl)4-[B(OC(=0)-CioH7)4].

[0224] Method of processing the organoboron salt

[0225] The method of manufacturing the organoboron salt disclosed herein affords an organoboron salt having a structure according to formula (I), which can, in turn, be transformed into a number of commercially valuable materials by reacting it with a further reagent.

[0226] Accordingly, also disclosed herein is a method of processing the organoboron salt, wherein the method comprises the steps of manufacturing an organoboron salt, wherein the organoboron salt is a compound according to formula (I), according to the method of manufacturing disclosed herein, reacting the organoboron salt with a further reagent.

[0227] Suitable further reagents include, but are not limited to hydride sources, water, (fluorinated) alcohols, diols, different (di)carboxylic acids and their salts, ammonium salts, and phosphonium salts. Non-limiting examples of suitable (fluorinated) alcohols include HOCF3, HOCH2CF3, HOCF2CF3, HOCH2CF2CF3, HOCF2CF2CF3, HOCH(CF3)2, HOCH2CF2CF2CF3, HOC(CF3)3, HOCH2CH2(CF2)nCF3wherein n is 1 , 3, 5, 7 or 9, and HOPhF. Non-limiting examples of suitable diols include perfluoropinacol. Non-limiting examples of suitable (di)carboxylic acids and their salts include oxalic acid, malonic acid, succinic acid, phtalic acid, isophthalic acid, tartaric acid, glycolic acid, and amino acids (e.g., glycine and valine), and salts thereof. Non-limiting examples of suitable ammonium salts include tetraalkylammonium salts, such as a tetramethylammonium salt or a tetraethylammonium salt. Non-limiting examples of suitable phosphonium salts include tetraalkylphosphonium salts, such as a tetramethylphosphonium salt or a tetraethylphosphonium salt.

[0228] For example, the method of processing the organoboron salt may comprise the steps of manufacturing an organoboron salt, wherein the organoboron salt is a compound according to formula (I), according to the method of manufacturing disclosed herein, reacting the organoboron salt with a hydride source (such as a metal hydride (e,g.

[0229] NaH, LiH, KH, CaH2or MgH2), a borohydride salt (e.g., NaBF , KBH4or LiBF ), an aluminium hydride salt (e.g., LiAIFL or NaAIH4), diisobutylaluminium hydride, or tris(trimethylsilyl)silane).

[0230] In other embodiments, the method of processing the organoboron salt comprises the steps of manufacturing an organoboron salt, wherein the organoboron salt is a compound according to formula (I), according to the method disclosed herein, reacting the compound according to formula (I) with HOCH(CF3)2, HOCH2CF2CF2CF3, HOPhF, or perfluoropinacol, thereby forming an electrolyte.

[0231] If desired, the cation of the compound according to formula (I) or the electrolyte can be exchanged. Accordingly, disclosed herein is a the method of processing the organoboron salt comprises the steps of manufacturing an organoboron salt, wherein the organoboron salt is a compound according to formula (I), according to the method disclosed herein, reacting the compound according to formula (I) with a cation source, thereby exchanging cation Xn+2 of the organoboron salt for another cation, optionally wherein the cation source is a salt having a cation selected from alkali metals (in particular, Li, Na, K, and Cs), earth alkali metals (in particular, Mg and Ca), Zn, NH4, N[C(1 -4)alkyl]4, P[C(1 -14)alkyl]4, imidazolium, pyrrolidinium, and piperidinium.

[0232] Suitable reaction conditions are described in e.g. US 2001 / 0033964, US 2996534A, and US 2923731A. For example, US 2001 / 0033964 and US 2923731A describe methods suitable for cation exchange. US 2938920A describes methods suitable for transesterification of the compound according to formula (I). These documents, in particular the methods described in their Examples, are incorporated by reference herein.

[0233] As discussed above, a particular advantage of compounds according to formula (I) obtained by the method of manufacturing according to the disclosure is that these compounds are substantially pure. Accordingly, also disclosed herein is a compound according to formula (I) obtainable by (or obtained by) the method of manufacturing according to the disclosure. The compound according to formula (I) may have a purity of at least 99.5%, in particular at least 99.9%, more in particular at least 99.99% (e.g. as determined by elemental analysis (optionally using ASTM E1621-22) and / or a combination of elemental analysis with XRD analysis and / or NMR spectroscopic analysis).

[0234] As used herein, “C(x)alkyl” refers to an alkyl group having x carbon atoms in a linear or branched arrangement. For example, the term “C(6)alkyl” refers to a hexyl group. As used herein, “C(x-y)alkyl” refers to an alkyl group having x to y carbon atoms in a linear or branched arrangement. The alkyl group may be partially unsaturated. For example, the term “C(1-5)alkyl” refers to an alkyl having 1 to 5 carbon atoms, i.e. to methyl, ethyl, propyl, butyl, and pentyl groups.

[0235] As used herein, “C(x-y)aryl” refers to an aromatic group having x to y carbon atoms. For example, the term “C(6-10)aryl” may refer to a benzyl or naphthyl group.

[0236] As used herein, “C(x-y)alkoxy” refers an alkyl group having x to y carbon atoms attached through an oxygen linking atom. For example, “C(1-3)alkoxy” refers to an alkyl group having one to three carbon atoms (i.e., methyl, ethyl, (iso-)propyl) attached through an oxygen linking atom, so to a methoxy, ethoxy or (iso-)propoxy group.

[0237] As used herein, “C(xi-yi)alkoxy-C(x2-y2)alkyl” refers to a “C(xi-yi)alkoxy” group attached to a C(x2-y2)alkyl group. The number of carbon atoms of the C(x-y)alkoxy group and the C(x- y)alkyl group are independent. For example, the term “C(1-5)alkoxy-C(1-5)alkyl” refers to a C(1-5)alkoxy group attached to a C(1-5)alkyl group.

[0238] As used herein, “C(xi-yi)alkoxy-C(x2-y2)cycloalkyl” refers to a “C(xi-yi)alkoxy” group attached to a C(x2-y2)cycloalkyl group, wherein “C(x2-y2)cycloalkyl” refers to a cycloalkyl group having X2 to y2 carbon atoms. The number of carbon atoms of the C(x-y)alkoxy group and the C(x- y)cycloalkyl group are independent. For example, the term “C(1-5)alkoxy-C(5-6)alkyl” refers to a C(1-5)alkoxy group attached to a cyclopentyl or a cyclohexyl group.

[0239] As used herein, “C(x-y)alcohol” refers to an organic alcohol having x to y carbon atoms. The organic alcohol may be free from heteroatoms. The organic alcohol may be linear or branched. The organic alcohol may be partially or wholly unsaturated. As an example, “C(1- 2)alcohol” can refer to e.g. methanol and ethanol.

[0240] As used herein, “halogen” refers to Cl, Br, F, and I. It is preferred that “halogen” is F.

[0241] As used herein, “ionic boron-oxygen compound” refers to an ionic compound having at least one boron-oxygen bond. Examples of ionic boron-oxygen compounds include borax and hydrates thereof, as well as other boron-containing minerals mentioned herein. Boric acid is not an ionic boron-oxygen compound. Examples

[0242] The following examples will illustrate the practice of the present invention in some of the preferred embodiments. Other embodiments within the scope of the claims will be apparent to one skilled in the art.

[0243] Example 1 : Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O710 H2O) using stoichiometric amounts of base

[0244] In the following, tincal (Na2B4O710 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0245] In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser borax decahydrate (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (105 mg, 2.62 mmol, 2 equiv.) and water were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at quantitative yield.

[0246] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0247] Example 2: Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O7-10 H2O) using an excess of base

[0248] In the following, tincal (Na2B4O710 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0249] In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser tincal (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (210 mg, 5.24 mmol, 4 equiv.) and water were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 90% yield. The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0250] Example 3: Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O710 H2O) in isopropanol

[0251] In the following, tincal (Na2B4O710 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0252] In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser tincal (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (105 mg, 2.62 mmol, 2 equiv.) and isopropanol were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 90% yield.

[0253] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0254] Example 4: Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O7-10 H2O) in acetonitrile

[0255] In the following, tincal (Na2B4O710 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0256] In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser tincal (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (105 mg, 2.62 mmol, 2 equiv.) and acetonitrile were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 90% yield.

[0257] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0258] Example 5: Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O710 H2O) in 1 :1 water and methanol solvent mixture

[0259] In the following, tincal (Na2B40y 10 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0260] In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser tincal (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (105 mg, 2.62 mmol, 2 equiv.) and a 1:1 (vol / vol) water and methanol solvent mixture were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 90% yield.

[0261] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0262] Example 6: Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O710 H2O) in 1 :1 water and ethanol solvent mixture

[0263] In the following, tincal (Na2B4O7- 10 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction: In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser tincal (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (105 mg, 2.62 mmol, 2 equiv.) and a 1:1 (vol / vol) water and ethanol solvent mixture were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 90% yield.

[0264] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0265] Example 7: Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O7-10 H2O) in 1 :1 water and isopropanol solvent mixture

[0266] In the following, tincal (Na2B4O7- 10 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0267] In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser tincal (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (105 mg, 2.62 mmol, 2 equiv.) and a 1:1 (vol / vol) water and isopropanol solvent mixture were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 90% yield.

[0268] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125). Example 8: Synthesis of sodium bis(oxalato) borate from tincal (Na2B4O7-10 H2O) in 1 :1 water and acetonitrile solvent mixture

[0269] In the following, tincal (Na2B4O7- 10 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0270] In a 50 mL round-bottom-flask (RBF) equipped with a reflux condenser tincal (500 mg, 1.31 mmol, 1 equiv.), oxalic acid (944 mg, 10.5 mmol, 8 equiv.), sodium hydroxide (105 mg, 2.62 mmol, 2 equiv.) and a 1:1 (vol / vol) water and acetonitrile solvent mixture were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 90% yield.

[0271] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0272] Example 9: Synthesis of sodium bis(oxalato) borate from anhydrous borax (Na2B4O7) in acetone under an atmosphere of dry nitrogen with sodium carbonate as base

[0273] In the following borax decahydrate (Na2B4O7) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0274] In a 1 L Schlenk flask equipped with a n overhead stirrer, anhydrous borax (26.4 g, 131.2 mmol, 1 eq.), oxalic acid (94.5 g, 1.05 mol, 8 eq) and acetone were added. To the mixture, sodium carbonate (13.91 g, 131.2 mmol, 1 eq.) was added in portions and the mixture stirred until effervescence ceased. The mixture was heated for 24 hours at 40 C. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 82% yield.

[0275] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0276] Example 10: Synthesis of sodium bis(oxalato) borate from tincalconite (Na2B4O7x 5 H2O) in acetonitrile under an atmosphere of dry nitrogen

[0277] In the following ground tincalconite (Na2B4O7X 5 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0278] In a 100 mL Schlenk flask ground tincalconite (1.00 g, 3.43 mmol, 1 eq.), oxalic acid (2.47 g, 27.5 mmol, 8 eq.), sodium hydroxide (275 mg, 6.87 mmol, 2 eq.) and acetonitrile were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 97% yield.

[0279] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0280] Example 11 : Synthesis of sodium bis(oxalato) borate from kernite (Na2B4O7x 4 H2O) in acetonitrile

[0281] In the following ground tincal (Na2B4O7X 4 H2O) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction:

[0282] In a 250 mL round bottom flask ground Kernite (2.07 g, 7.57 mmol, 1 eq.), oxalic acid (5.46 g, 60.6 mmol, 8 eq.), sodium carbonate (803 mg, 7.57 mmol, 1 eq.) and acetonitrile were added. The mixture was heated for 4 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 59% yield.

[0283] The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

[0284] Example 12: Synthesis of sodium bis(malonato) borate from anhydrous borax (Na2B4O7) in acetonitrile under an atmosphere of dry nitrogen

[0285] In the following borax (Na2B4O?) was allowed to react with malonic acid and sodium hydroxide according to the following reaction:

[0286] Na2B4O7+ 2 NaOH + 8 C3O4H4- ► 4 NaB(C3H2O4)2 + 9 H2O

[0287] In a 250 mL Schlenk flask anhydrous borax (5.00 g, 24.8 mmol, 1 eq.), malonic acid (20.7 g, 199 mmol, 8 eq.), sodium hydroxide (1.99 g, 49.7 mmol, 2 eq.) and acetonitrile (100 mL) were added. The mixture was heated for 24 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(malonato) borate at 97% yield.

[0288] The identity and purity of the obtained compound were confirmed by spectroscopic and analytical methods, including nuclear magnetic resonance (1H,13C and11B NMR) and infrared spectroscopy. The recorded spectra were consistent with the expected structure and composition of the target compound, thereby confirming its successful synthesis. No discrepancies or impurities were detected within the limits of analytical accuracy.

[0289] Example 13: Synthesis of sodium bis(2-ethyl malonato) borate from anhydrous borax (Na2B4O7) in acetonitrile under an atmosphere of dry nitrogen

[0290] In the following borax (Na2B4O?) was allowed to react with 2-ethyl malonic acid and sodium hydroxide according to the following reaction: In a 100 mL Schlenk flask anhydrous borax (250 mg, 1.24 mmol, 1 eq.), 2-ethyl malonic acid (1.31 g, 9.94 mmol, 8 eq.), sodium hydroxide (99.4 mg, 2.48 mmol, 2 eq.) and acetonitrile (25 mL) were added. The mixture was heated for 24 hours at reflux. Afterwards, the solids were filtered off and the filtrate concentrated under reduced pressure and heat, yielding sodium bis(2-ethyl malonato) borate at 76% yield.

[0291] The identity and purity of the obtained compound were confirmed by spectroscopic and analytical methods, including nuclear magnetic resonance (1H,13C and11B NMR) and infrared spectroscopy. The recorded spectra were consistent with the expected structure and composition of the target compound, thereby confirming its successful synthesis. No discrepancies or impurities were detected within the limits of analytical accuracy.

[0292] Example 14: Synthesis of sodium bis(maleato) borate from anhydrous borax (Na2B4O7) in acetonitrile under an atmosphere of dry nitrogen

[0293] In the following borax (Na2B4O?) was allowed to react with maleic acid and sodium hydroxide according to the following reaction:

[0294] In a 250 mL round-bottom flask anhydrous borax (500 mg, 2.48 mmol, 1 eq.), maleic acid (2.31 g, 19.9 mmol, 8 eq.), sodium hydroxide (199 mg, 4.97 mmol, 2 eq.) and acetonitrile (60 mL) were added. The mixture was heated for 20 hours at reflux. Afterwards, the solids were filtered off and the solids washed. The final solids were dried under reduced pressure and heat , yielding sodium bis(maleate) borate at 50% yield.

[0295] The identity and purity of the obtained compound were confirmed by spectroscopic and analytical methods, including nuclear magnetic resonance (1H,13C and11B NMR) and infrared spectroscopy. The recorded spectra were consistent with the expected structure and composition of the target compound, thereby confirming its successful synthesis. No discrepancies or impurities were detected within the limits of analytical accuracy.

[0296] Example 15: Synthesis of calcium bis(oxalato) borate from colemanite (Ca2B60n x 5 H2O) in acetonitrile

[0297] In the following ground colemanite (Ca2BeOn x 5 H2O) was allowed to react with oxalic acid and calcium hydroxide according to the following reaction: Ca2B6Onx 5 H2O +1 Ca(OH)2+ 12 C2O4H2- ► 3 Ca(B(C2O4)2)2+ 18 H2O

[0298] In a 100 mL round bottom flask ground colemanite (1.00 g, 2.43 mmol, 1 eq.), oxalic acid (2.63 g, 29.2 mmol, 8 eq.), calcium hydroxide (180 mg, 2.42 mmol, 1 eq.) and acetonitrile were added. The mixture was heated for 24 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding calcium bis(oxalato) borate at 76% yield.

[0299] The identity and purity of the obtained compound were confirmed by spectroscopic and analytical methods, including nuclear magnetic resonance (13C and11B NMR) and infrared spectroscopy. The recorded spectra were consistent with the expected structure and composition of the target compound, thereby confirming its successful synthesis. No discrepancies or impurities were detected within the limits of analytical accuracy.

[0300] Example 16: Synthesis of magnesium bis(oxalato) borate from magnesium tetraborate (MgB4O7) in acetonitrile

[0301] In the following ground magnesium tetraborate (MgB4C>7) was allowed to react with oxalic acid and magnesium hydroxide according to the following reaction:

[0302] MgB4O7+ 1 Mg(OH)2+ 8 C2O4H2- ► 2 Mg(B(C2O4)2)2+ 9 H2O

[0303] In a 100 mL round bottom flask ground magnesium tetraborate (1.00 g, 2.43 mmol, 1 eq.), oxalic acid (4.01 g, 44.6 mmol, 8 eq.), magnesium hydroxide (325 mg, 2.42 mmol, 1 eq.) and acetonitrile were added. The mixture was heated for 18 hours at 60 °C. The solvent was evaporated off under reduced pressure and heat, yielding magnesium bis(oxalato) borate at 11% yield.

[0304] The identity and purity of the obtained compound were confirmed by spectroscopic and analytical methods, including nuclear magnetic resonance (13C and11B NMR) and infrared spectroscopy. The recorded spectra were consistent with the expected structure and composition of the target compound, thereby confirming its successful synthesis. No discrepancies or impurities were detected within the limits of analytical accuracy.

[0305] Example 17: Synthesis of sodium bis(oxalato) borate from anhydrous borax (Na2B4O7) in acetonitrile under an atmosphere of dry nitrogen

[0306] In the following, borax (Na2B4O?) was allowed to react with oxalic acid and sodium hydroxide according to the following reaction: In a 50 mL Schlenk flask anhydrous borax (100 mg, 0,497 mmol, 1 equiv.), oxalic acid (358 mg, 3.98 mmol, 8 equiv.), sodium hydroxide (398 mg, 9.94 mmol, 2 equiv.) and acetonitrile were added. The mixture was heated for 24 hours at reflux. The solvent was evaporated off under reduced pressure and the product was washed with the solvent, yielding sodium bis(oxalato) borate at 98% yield. The13C and11B NMR spectroscopic data as well as the IR spectrum of the reaction product confirmed the purity of the compound, and the spectra were identical compared to the spectra reported in literature for the same compound. Detailed IR spectroscopic literature values for comparison can be found inter alia in (Journal of Power Sources, 2014, Volume 248, Pages 77-82), and NMR spectroscopic literature values for comparison can be found inter alia in (Radiation Physics and Chemistry, 2009, Volume 78, Pages 1120-1125).

Claims

We claim:

1. Method of manufacturing an organoboron salt, the method comprising reacting an ionic boron-oxygen compound with a base and one or more (di)carboxylic acids, or a trimethylsilyl-protected derivative thereof, in a total amount of at least 2.0 moles of the (di)carboxylic acid or the trimethylsilyl-protected derivatives thereof per mole of boron in the total of the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (I),wherein:- Ri and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;- R1 , R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; or- R1 and R2 are fused and form a five-, six-, or seven-membered ring that is optionally substituted with one or more of halogen, hydroxyl, C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl are each optionally substituted with one or more halogen, and R3 and R4 are each independently selected from the group consisting of H, C(1-13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1-13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen; and- X is a mono-, di-, or trivalent cation;- when X is a monovalent cation, n is 1 ;- when X is a divalent cation, n is 2; and- when X is a trivalent cation, n is 3; wherein the ionic boron-oxygen compound and the base comprise a cation and wherein the cation of the ionic boron-oxygen compound and the cation of the base are the same as X.

2. The method according to claim 1 , wherein the reacting comprises the use of one or more dicarboxylic acids or trimethylsilyl-protected derivatives thereof and the organoboron salt is a compound according to formula (la),wherein:- Rs, Re, R?, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;- X is a mono-, di-, or trivalent cation;- when X is a monovalent cation, n is 1 ;- when X is a divalent cation, n is 2;- when X is a trivalent cation, n is 3; and- each m is independently 0, 1 , or 2.

3. The method according to claim 1 or 2, wherein the reacting comprises the use of one or more monocarboxylic acids or the trimethylsilyl-protected derivatives thereof in a total amount of at least 4.0 moles per mole boron in the ionic boron-oxygen compound and wherein the organoboron salt is a compound according to formula (I),wherein:- Ri, R2, R3, and R4 are each independently selected from the group consisting of H, C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl, wherein the C(1 -13)alkyl, C(2-8)alkenyl, and C(6-10)aryl are each optionally substituted with one or more hydroxyl, C(1-4)alkoxy, and / or halogen;- X is a mono-, di-, or trivalent cation;- when X is a monovalent cation, n is 1 ;- when X is a divalent cation, n is 2; and- when X is a trivalent cation, n is 3.

4. The method according to any one of claims 1 to 3, wherein the ionic boron-oxygen compound is a compound according to formula (a), XpBqOr(OH)s, or a hydrate thereof, wherein: X is Li, Na, or K; p is 1 or 2; q is from 2 to 10; r is from 2 to 13; and s is from 0 to 10, provided that p + 3q = 2r + s; and / or a compound according to formula (b), XpBqOr(OH)s, or a hydrate thereof, wherein: X is Mg or Ca; p is 2 or 3; q is from 5 to 10; r is from 5 to 13; and s is from 0 to 5, provided that 2p + 3q = 2r + s.

5. The method according to any one of claims 1 to 4, wherein the ionic boron-oxygen compound is one or more selected from the group consisting of borax or a hydrate thereof, colemanite, meyerhofferite, inyoite, pandermite, inderite, boracite, salts of BO2; salts of B3O3(OH)4-, salts of B4O5(OH)42-, salts of B3O3(OH)52; and salts of B(OH)4; in particular wherein the ionic boron-oxygen compound is one or more selected from the group consisting of borax or a hydrate thereof, colemanite, meyerhofferite, inyoite, pandermite, inderite, and boracite, more in particular wherein the ionic boron-oxygen compound is selected from the group consisting of borax, kernite, tincalconite, tincal, colemanite, meyerhofferite, inyoite, pandermite, inderite, and boracite.

6. The method according to any one of claims 1 to 5, wherein the ionic boron-oxygen compound is one or more selected from the group consisting of salts of BCh', salts of B3O3(OH)4-, salts of B4O5(OH)42-, salts of B3O3(OH)52’, and salts of B(OH)4’.

7. The method according to any one of claims 1 to 6, wherein the reacting is done in the presence of a solvent, optionally wherein the solvent is water, a nitrile, a C(1-8)alcohol, a C(1-4)alkoxy-C(1-5)alkyl optionally substituted with one or more of hydroxy and C(1)alkoxy, a C(1-2)alkoxy-C(5-6)cycloalkyl, 1 ,4-dioxane, tetra hydrofuran, 2-methyltetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydropyran, a nitro-C(1-4)alkyl, or a mixture thereof, in particular wherein the nitrile is acetonitrile and / or wherein the C(1-8)alcohol is a C(3-8)alcohol.

8. The method according to any one of claims 1 to 7, wherein the reacting comprises using from 1 .0 to 5.0 moles of base per mole of cation in the total of the ionic boron-oxygen compound, in particular from 1 .0 to 3.0 moles of base per mole of cation, more in particular about 2.0 moles of base per mole of cation.

9. The method according to any one of claims 1 to 8, wherein the base is selected from the group consisting of NaOH, KOH, LiOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, Li2CO3, CaCO3, MgCO3, NaHCO3, KHCO3, LiHCO3, Ca(HCO3)2, Mg(HCO3)2, Na2O, K2O, l_i2O, CaO, and MgO.

10. The method according to any one of claims 1 to 9, wherein the method comprises the steps of: reacting an ionic boron-oxygen compound selected from one or more of the group consisting of borax and hydrates thereof, in particular borax, kernite, tincalconite, and tincal, with a base selected from the group consisting of NaOH, Na2CO3, NaHCO3, and Na2O and one or more dicarboxylic acids, or trimethylsilyl-protected derivatives thereof, in a total amount of at least 2.0 moles of the dicarboxylic acid or trimethylsilyl-protected derivatives thereof per mole of boron in the ionic boron-oxygen compound, thereby forming the organoboron salt, wherein the organoboron salt is a compound according to formula (la),wherein:- Rs, Re, R7, and Rs are each independently selected from H, halogen, hydroxyl, C(1- 3)alkyl, C(1-4)alkoxy, and C(2-3)alkenyl, wherein the C(1-3)alkyl, C(1-4)alkoxy, and C(2- 3)alkenyl are each optionally substituted with one or more halogen;- X is Na;- n is 1 ; and- each m is independently 0, 1 , or 2 (in particular, each m is independently 0 or 1), optionally wherein reacting comprises using a total amount of at least 1.0 moles of base per mole of sodium in the ionic boron-oxygen compound.11 . The method according to any one of claims 1 to 10, wherein water is removed during the reaction using a solid, water-absorbing material, in particular using molecular sieves and / or alumina.

12. The method according to any one of claims 1 to 11 , wherein the method further comprises the step of isolating the compound according to formula (I).

13. Method of processing an organoboron salt, wherein the method comprises the steps of manufacturing an organoboron salt, wherein the organoboron salt is a compound according to formula (I), according to the method of any one of claims 1 to 12, reacting the organoboron salt with a further reagent.

14. The method according to claim 13, wherein the further reagent is selected from the group consisting of hydride sources, water, optionally fluorinated alcohols, diols, dicarboxylic acids and their salts, ammonium salts, and phosphonium salts, in particular wherein the further reagent is a hydride source or an optionally fluorinated alcohol.

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