Hydrosilylation processes catalyzed by iron complexes

Abstract

The present invention relates to a hydrosilylation process of an unsaturated compound comprising at least one alkenyl or alkynyl functional group using a compound comprising at least one hydrosilyl functional group, said process being catalyzed by an iron complex of formula Fe[Si(SiR3)3]2L n wherein each R represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, optionally substituted by one or more halogen atoms, each L represents an ether ligand, and n = 1, 2 or 3. The present invention also relates to a process for the preparation of said iron complex, as well as to its use as a hydrosilylation catalyst of olefins or acetylenes.

Description

Technical Field

[0001] This invention relates to the hydrosilylation reaction between alkene or alkyne compounds and compounds comprising at least one hydrogen atom bonded to a silicon atom. More particularly, this invention relates to the use of novel catalysts for these reactions. These catalysts, in particular, enable the curing of organosilicon compositions by crosslinking. Background Technology

[0002] In the hydrosilylation (also known as polyaddition) reaction, an unsaturated compound, i.e., a compound containing at least one double or triple bond of unsaturation, reacts with a compound containing at least one silyl functional group (i.e., a hydrogen atom bonded to a silicon atom). This reaction can be described, for example, in the case of alkene-type unsaturation:

[0003]

[0004] Alternatively, in the case of alkyne-type unsaturation:

[0005]

[0006] Hydrosilylation may be accompanied by, or even sometimes replaced by, dehydrosilylation. This reaction can be described as follows:

[0007]

[0008] Hydrosilylation is particularly used for crosslinking organosilicon compositions containing organopolysiloxanes with alkenyl or alkynyl units and organopolysiloxanes containing hydroxysilyl functional groups.

[0009] The hydrosilylation of unsaturated compounds is typically achieved by means of organometallic or metallic catalysts. Currently, platinum catalysts are suitable for this reaction. Consequently, most industrial hydrosilylation methods, especially for alkenes, are catalyzed by Speier hexachloroplatinic acid or by the Karstedt Pt(0) complex of the general formula Pt2(divinyltetramethyldisiloxane)3 (abbreviated as Pt2(DVTMS)3).

[0010] In the early 2000s, the preparation of platinum-carbaene complexes enabled the production of more stable catalysts (see, for example, patent application WO 01 / 42258).

[0011] However, the use of platinum catalysts, whether metal or organometallic, remains problematic. It is an expensive metal, becoming increasingly scarce, and its price fluctuates greatly. Its use on an industrial scale is therefore difficult. Consequently, it is desirable to minimize the amount of catalyst required for the reaction without reducing the reaction yield and rate. Numerous studies have been conducted to find alternatives to Karstedt catalysts.

[0012] In this context, research has been conducted for many years to find novel catalysts for the hydrosilylation of olefins.

[0013] For example, the use of iron-based catalysts has been described in patent application WO 2019 / 008279. In that document, the catalyst described is of the general formula [Fe(N(SiR3)2)]. x The catalysts are iron compounds, where the symbol R represents a hydrogen atom or a hydrocarbon group, x has a value of 1, 2, or 3, and y has a value of 1 or 2. It appears that the catalysts are capable of efficiently catalyzing hydrosilylation or dehydrosilylation reactions. These catalysts particularly exhibit the advantage of not requiring the use of solvents, as they show good solubility in silicone oils. However, in crosslinking tests of the silicone compositions, it has been found that the stirring stop time is approximately several hours.

[0014] Patent application US2016 / 0023196 describes a mononuclear iron complex exhibiting catalytic activity for the reduction, hydrogenation, and hydrosilylation of carbonyl compounds. This iron complex has the general formula [Fe(SiR3)2]CO. n L m Specifically, n has values ​​between 1 and 3. This complex therefore necessarily contains one or more carbonyl ligands coordinated to iron. According to the literature, carbon monoxide (CO) is the necessary ligand to ensure catalytic activity.

[0015] International patent application WO 2010 / 016416 describes a catalyst for a hydrosilylation reaction, comprising a catalyst of general formula X. t -Fe-R 1 s (Y u The compound represented by ) is an iron complex compound, where X represents a ligand selected from those having unsaturated aliphatic C 4-10 Cyclic structures of groups, tripyrazole borate, tetrafluoroborate, hexafluorophosphate, porphyrin, and phthalocyanine; R 1 The symbol represents a ligand formed by H, alkyl, aryl, or SiR3 groups, and Y represents a ligand formed by an ammonia molecule, a carbonyl molecule, an oxygen atom, an oxygen molecule, an amine molecule, a phosphine molecule, or a phosphite molecule. The only exemplified iron complex is cyclopentadienylmethyldicarbonyl iron.

[0016] It is against this backdrop that the inventors sought more effective alternatives to the aforementioned catalysts. A catalyst capable of catalyzing the hydrosilylation reaction between silane functional groups and alkene or alkyne functional groups is desired. Advantageously, the reaction is desirable to be rapid and to proceed at moderate temperatures, preferably ambient temperatures. Furthermore, the catalyst is desirable to contain sufficient, inexpensive, and non-toxic chemical elements.

[0017] More recently, a scientific publication by S. Arata and Y. Sunada (An Isolable Iron(II)Bis(Supersilyl) Complex as an Effective Catalyst for Reduction Re-actions, Dalton Trans., 2019, 48, 2891-2895) describes iron-based supersilyl complexes of formula Fe[Si(SiMe3)3]2(THF)2 and their activity for the hydrosilylation of carbonyl compounds and the reductive silylation of molecular nitrogen. However, this publication does not describe the use of these catalysts for the hydrosilylation of alkenes or alkynes. Furthermore, XRD analysis of the purple crystals obtained in the publication by S. Arata and Y. Sunada indicates that the obtained compound (1) has the formula C 34 H 70 FeO4Si8 and 823.46 g.mol -1 The molecular weight (see supporting information in this article). The compound isolated in this publication does not correspond to the complex Fe[Si(SiMe3)3]2(THF)2. Summary of the Invention

[0018] Overview of the Invention

[0019] The subject of this invention is a hydrosilylation method of an unsaturated compound (A) containing at least one functional group selected from alkenes and alkynes using a compound (B) containing at least one silyl functional group, said method being catalyzed by an iron complex (C) represented by formula (1):

[0020] Fe[Si(SiR3)3]2L n (1)

[0021] in:

[0022] - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms.

[0023] - Each L represents an ether ligand independently, and

[0024] -n = 1, 2 or 3.

[0025] Another subject of the present invention is a composition comprising at least one unsaturated compound (A), at least one compound (B), and an iron complex (C), wherein the unsaturated compound (A) comprises at least one functional group selected from alkene and alkyne functional groups, the compound (B) comprises at least one silyl functional group, and the iron complex (C) is represented by formula (1):

[0026] Fe[Si(SiR3)3]2L n (1)

[0027] in:

[0028] - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms.

[0029] - Each L represents an ether ligand independently, and

[0030] -n = 1, 2 or 3.

[0031] Surprisingly, the inventors have discovered that the iron complex (C) described above can be advantageously recrystallized to effectively catalyze the hydrosilylation reaction of alkenes or alkynes. Another subject of the invention thus lies in a method for preparing the iron complex (C) represented by formula (1):

[0032] Fe[Si(SiR3)3]2L n (1)

[0033] in:

[0034] - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms.

[0035] - Each L represents an ether ligand independently, and

[0036] -n = 1, 2, or 3;

[0037] The method includes a step of preparing a crude iron complex (C), followed by a step of recrystallizing the crude iron complex (C).

[0038] The purified iron complex (C) obtained or obtainable by the method described herein is the subject of this invention, as is its use as a catalyst for the hydrosilylation of olefins or alkynes.

[0039] Detailed description of the invention

[0040] In this text, symbols This is attributed to the coordinate covalent bond of the ligand L, which contains a free electron pair.

[0041] Unless otherwise stated, all viscosities of silicone oils considered in this disclosure correspond to the so-called “Newtonian” dynamic viscosity at 25°C, i.e., the dynamic viscosity measured in a manner known per se using a Brookfield viscometer at a sufficiently low shear rate gradient that makes the measured viscosity independent of the velocity gradient.

[0042] Although not described, possible tautomer forms of the compounds described in this disclosure are included within the scope of the invention.

[0043] In this invention, the alkyl group can be linear or branched. The alkyl group preferably contains 1-30 carbon atoms, more preferably 1-12 carbon atoms, and even more preferably 1-6 carbon atoms. The alkyl group can be selected from, for example, the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl.

[0044] In this invention, the cycloalkyl group can be monocyclic or polycyclic, preferably monocyclic or bicyclic. The cycloalkyl group preferably contains 3-30 carbon atoms, more preferably 3-8 carbon atoms. The cycloalkyl group can be selected from, for example, the following groups: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, and norbornyl.

[0045] In this invention, the aryl group can be monocyclic or polycyclic, preferably monocyclic, and preferably contains 6-30 carbon atoms, more preferably 6-18 carbon atoms. The aryl group can be unsubstituted, or can be substituted once or multiple times with alkyl groups. The aryl group can be selected from phenyl, naphthyl, anthraceneyl, phenanthrene, etc. The compounds are methyl, tolyl, xylyl, diisopropylphenyl, and triisopropylphenyl.

[0046] In this invention, the aryl-alkyl group comprises 6-30 carbon atoms, more preferably 7-20 carbon atoms. The aryl-alkyl group may be selected, for example, from the following groups: benzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl, and naphthylpropyl.

[0047] In this invention, the halogen atom may be selected, for example, from fluorine, bromine, chlorine, and iodine, with fluorine being preferred. The alkyl group substituted with fluorine may be, for example, trifluoropropyl.

[0048] The subject of this invention is a novel method for the hydrosilylation of an unsaturated compound (A) catalyzed by an iron complex (C) and a compound (B) containing at least one hydroxysilyl functional group. The iron complex (C) according to the invention is represented by formula (1):

[0049] Fe[Si(SiR3)3]2L n (1)

[0050] in:

[0051] - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms.

[0052] - Each L represents an ether ligand independently, and

[0053] -n = 1, 2 or 3.

[0054] Preferably, each R independently represents a group selected from alkyl, cycloalkyl, aryl, and aryl-alkyl groups, which may optionally be substituted with one or more halogen atoms. More preferably, each R independently represents C1-C2. 12 Alkyl, C3-C8 cycloalkyl, C6-C 12 Aryl or C7-C 24 Aryl-alkyl. More preferably, each R independently represents a group selected from methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl, and phenyl. More preferably, the R group is methyl.

[0055] In formula (1) according to the invention, each L represents an ether ligand that coordinates with iron via a free electron pair carried by an oxygen atom. n represents the number of ligands L. n has a value of 1, 2, or 3. Preferably, n has a value of 2. When L has a value of 2 or 3, the ligands L can be the same or different. In formula (1), iron is in the +II oxidation state.

[0056] The ether ligand L can be selected from formula R 1 OR 2 The compound in which R 1 and R 2 Independent of each other, these represent substituted or unsubstituted hydrocarbon groups having 1-30 carbon atoms, which optionally contain one or more heteroatoms, or R 1 and R 2 Together with the oxygen atoms they are bonded to, they form a cyclic hydrocarbon group containing one or more heteroatoms. These one or more heteroatoms are preferably selected from O, N, S, and P.

[0057] According to the first implementation plan, R 1 and R 2 Each of these groups independently represents a substituted or unsubstituted hydrocarbon group having 1-30 carbon atoms, optionally containing one or more heteroatoms. The one or more heteroatoms are preferably selected from O, N, S, and P. Preferably, R... 1 and R 2 Each group independently represents a group selected from alkyl, cycloalkyl, aryl, and aryl-alkyl groups, which may optionally be substituted with one or more halogen atoms, and one or more carbon atoms may optionally be substituted with oxygen atoms. More preferably, R 1 and R2 C1-C are represented independently of each other. 12 Alkyl, C3-C8 cycloalkyl, C6-C 12 Aryl, C7-C 24 aryl-alkyl, (C1-C 12 alkyl)-oxy-(C1-C 12 alkyl) group, (C3-C8 cycloalkyl)-oxy-(C1-C 12 alkyl groups, (C6-C) 12 aryl)-oxy-(C1-C 12 alkyl group or (C7-C) 24 aryl-alkyl)-oxy-(C1-C) 12 Alkyl group. More preferably, R 1 and R 2 Each of these groups independently represents a group selected from methyl, ethyl, propyl, xylyl, tolyl, phenyl, methoxymethyl, methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, propoxymethyl, propoxyethyl, propoxypropyl, phenoxymethyl, phenoxyethyl, and phenoxypropyl. The ligand L may, for example, be selected from the following groups: methyl ether, ethyl ether, ethyl methyl ether, and dimethoxyethane.

[0058] According to the second implementation plan, R 1 and R 2 Together with the oxygen atoms they are bonded to, they form a cyclic hydrocarbon group containing one or more heteroatoms. These one or more heteroatoms are preferably selected from O, N, S, and P. The ligand L can be selected from a cyclic compound, preferably a monocyclic compound, containing 1 or 2 oxygen atoms and 2-12 carbon atoms, preferably 2-6 carbon atoms, optionally substituted once or multiple times with a halogen atom. The ligand L can be selected, for example, from the following groups: tetrahydrofuran, ethylene oxide, 1,3-epoxypropane, tetrahydropyran, oxetane, 1,2-di( ... Alkane, 1,3-di Alkane and 1,4-di Alkane. Preferably, ligand L can be tetrahydrofuran.

[0059] According to a particularly preferred embodiment, the iron complex (C) according to the invention can be the following compound:

[0060]

[0061] Surprisingly, the inventors have discovered that the iron complex (C) as described above can be advantageously recrystallized to effectively catalyze the hydrosilylation reaction of olefins or alkynes. Another subject of the invention is therefore a method for preparing the iron complex (C) as described above, the method comprising a preparation step of crude iron complex (C), followed by a recrystallization step of the crude iron complex (C).

[0062] The preparation of crude iron complex (C) can be carried out according to any method known to those skilled in the art or described in the literature. For example, reference can be made to the preparation method described in the following literature: S. Arata and Y. Sunada, “An Isolable Iron(II)Bis(Supersilyl) Complex as an Effective Catalyst for Reduction Reactions”, Dalton Trans., 2019, 48, 2891-2895.

[0063] According to one embodiment, the iron complex (C) can be prepared by reacting an iron(II) halide, such as FeCl2 or FeBr2, with a basic salt of a metasilylated anion, such as KSi(SiR3)3, in the presence of ligand L. The amount of the basic salt of the metasilylated anion is at least 2 molar equivalents relative to the iron halide. Ligand L may be added in excess. Typically, ligand L may be used as a solvent for the reaction. At the end of the reaction, the iron complex (C) is separated from the reaction medium and optionally crystallized according to techniques known to those skilled in the art. Crude iron complex (C) is thus obtained.

[0064] According to the present invention, the crude iron complex (C) undergoes a recrystallization step. The recrystallization solvent may be selected from pentane, toluene, hexane, heptane, cyclopentane, cyclohexane, and methylcyclohexane. Preferably, the recrystallization solvent is pentane. The volume of the recrystallization solvent is preferably 0.5 ml to 5.0 ml per 100 mg of crude complex, more preferably 1.0 ml to 2.0 ml per 100 mg of crude complex.

[0065] The purified iron complex (C) is also the subject of this invention, as is its use as a catalyst for the hydrosilylation of olefins or alkynes.

[0066] It has been found that the iron complex (C) as described above can be used as a catalyst for the hydrosilylation reaction between an unsaturated compound (A) containing at least one functional group selected from alkene and alkyne functional groups and a compound (B) containing at least one silyl functional group.

[0067] The hydrosilylation reaction may be accompanied by a dehydrosilylation reaction. The iron complex (C) as described above can also be advantageously used as a catalyst for the dehydrosilylation reaction between an unsaturated compound (A) containing at least one functional group selected from alkene and alkyne functional groups and a compound (B) containing at least one hydrosilylation functional group. In this text, unless otherwise stated, any comments or descriptions relating to the hydrosilylation reaction apply to the dehydrosilylation reaction.

[0068] Another subject of the present invention is a composition comprising at least one unsaturated compound (A), at least one compound (B), and an iron complex (C), wherein the unsaturated compound (A) comprises at least one functional group selected from alkene and alkyne functional groups, the compound (B) comprises at least one silyl functional group, and the iron complex (C) is represented by formula (1):

[0069] Fe[Si(SiR3)3]2L n (1)

[0070] in:

[0071] - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms.

[0072] - Each L represents an ether ligand independently, and

[0073] -n = 1, 2 or 3.

[0074] The unsaturated compound (A) used in the hydrosilylation method according to the invention is a compound containing at least one alkene or alkyne unsaturation that does not form part of an aromatic ring. The unsaturated compound (A) contains at least one functional group selected from alkene and alkyne functional groups, preferably at least one functional group selected from alkene functional groups. It may be selected from those known to those skilled in the art, and it does not contain reactive chemical functional groups that could impair or even prevent the hydrosilylation reaction.

[0075] According to one embodiment, the unsaturated compound (A) comprises one or more alkene functional groups and 2-40 carbon atoms. According to another embodiment, the unsaturated compound (A) comprises one or more alkynyl functional groups and 2-40 carbon atoms.

[0076] The unsaturated compound (A) may preferably be selected from acetylene, C1-C4 alkyl acrylates and methacrylates, acrylic acid or methacrylic acid, alkenes, preferably octene and more preferably 1-octene, allyl alcohols, allylamines, glycidyl and allyl ethers, piperidine and allyl ethers, preferably sterically hindered piperidine and allyl ethers, styrene, preferably α-methylstyrene, 1,2-epoxy-4-vinylcyclohexane, chlorinated alkenes, preferably allyl chloride, and fluorinated alkenes, preferably 4,4,5,5,6,6,7,7,7-nonafluoro-1-heptene.

[0077] The unsaturated compound (A) can be a disiloxane, such as vinylpentamethyldisiloxane and divinyltetramethyldisiloxane.

[0078] The unsaturated compound (A) may be selected from compounds containing multiple olefin functional groups, preferably two or three olefin functional groups, and particularly preferably, compound (A) is selected from the following compounds:

[0079]

[0080] According to a particularly preferred embodiment, the unsaturated compound (A) can be an organopolysiloxane compound containing one or more olefin functional groups, preferably at least two olefin functional groups. The hydrosilylation of olefins is one of the key reactions in organosilicon chemistry. It not only enables crosslinking between organopolysiloxanes with SiH functional groups and organopolysiloxanes with alkenyl functional groups to form a network and provide mechanical properties to the material, but also enables the functionalization of organopolysiloxanes with SiH functional groups to modify their physical and chemical properties. The organopolysiloxane compound can be formed, in particular, from the following units:

[0081] -At least two silyloxy units of the following formula: Vi a U b SiO (4-a-b) / 2

[0082] in:

[0083] V i It is a C2-C6 alkenyl group, preferably a vinyl group.

[0084] U is a monovalent hydrocarbon group having 1-12 carbon atoms, preferably selected from alkyl groups having 1-8 carbon atoms such as methyl, ethyl, or propyl, cycloalkyl groups having 3-8 carbon atoms, and aryl groups having 6-12 carbon atoms.

[0085] a = 1, 2, or 3, preferably a = 1 or 2; b = 0, 1, or 2; and the sum of a + b = 1, 2, or 3; and

[0086] -Optionally, a unit having the following formula: U cSiO (4-c) / 2

[0087] U has the same meaning as above, and c = 0, 1, 2 or 3.

[0088] It should be understood that in the above formula, if there are multiple U groups, they can be the same as or different from each other.

[0089] These organopolysiloxane compounds containing one or more alkene functional groups can exhibit a linear structure, which is essentially composed of units selected from silanoxy groups Vi₂SiO₃. 2 / 2 ViUSiO 2 / 2 and U2SiO 2 / 2 The silaneoxy unit "D" and "D" Vi "and selected from the silanoxy unit ViU2SiO" 1 / 2 Vi2USiO 1 / 2 and U3SiO 1 / 2 The terminal silaneoxy units "M" and "M" Vi Composed of the symbols Vi and U as described above.

[0090] As the end "M" and "M" Vi Examples of the unit may refer to trimethylsilyloxy, dimethylphenylsilyloxy, dimethylvinylsilyloxy, or dimethylhexenylsilyloxy.

[0091] As "D" and "D" Vi Examples of the unit may refer to dimethylsilyloxy, methylphenylsilyloxy, methylvinylsilyloxy, methylbutenylsilyloxy, methylhexenylsilyloxy, methyldecenylsilyloxy, or methyldecadienylsilyloxy.

[0092] Examples of linear organopolysiloxanes comprising one or more olefin functional groups according to the present invention include:

[0093] - Poly(dimethylsiloxane) with dimethylvinylsilyl end groups;

[0094] - Poly(dimethylsiloxane-co-methylphenylsiloxane) with dimethylvinylsilyl end groups;

[0095] - Poly(dimethylsiloxane-co-methylvinylsiloxane) with dimethylvinylsilyl terminus;

[0096] - Poly(dimethylsiloxane-co-methylvinylsiloxane) with trimethylsilyl terminating groups; and

[0097] - Cyclic poly(methylvinylsiloxane).

[0098] In the most preferred form, the organopolysiloxane compound containing one or more olefin functional groups comprises a terminal dimethylvinylsilyl unit. More preferably, the organopolysiloxane compound containing one or more olefin functional groups is a poly(dimethylsiloxane) having a dimethylvinylsilyl terminal.

[0099] Organosilicon oils typically have a viscosity of 1 mPa·s to 2,000,000 mPa·s. Preferably, the organopolysiloxane compound containing one or more olefin functional groups is an organosilicon oil with a dynamic viscosity of 20 mPa·s to 100,000 mPa·s, more preferably 20 mPa·s to 80,000 mPa·s, and more preferably 100 mPa·s to 50,000 mPa·s at 25°C.

[0100] Optionally, organopolysiloxane compounds containing one or more olefin functional groups may additionally contain a silanoxy unit "T" (USiO). 3 / 2 ) and / or silaneoxy unit "Q" (SiO) 4 / 2 The symbol U is as described above. Organopolysiloxane compounds containing one or more alkene functional groups exhibit a branched structure.

[0101] Examples of branched organopolysiloxanes (also known as resins) that may be organopolysiloxane compounds containing one or more olefin functional groups according to the present invention are:

[0102] -MD Vi Q, in which a vinyl group is included in unit D.

[0103] -MD Vi TQ, in which vinyl groups are included in unit D.

[0104] -MM Vi Q, wherein the vinyl group is included in a portion of the unit M,

[0105] -MM Vi TQ, wherein the vinyl group is included in a portion of unit M,

[0106] -MM Vi DD Vi Q, in which vinyl groups are included in a portion of units M and D,

[0107] -and its mixtures,

[0108] Where M Vi = Formula (U)2(vinyl)SiO 1 / 2 The silyloxy unit, D Vi = Formula (U)(vinyl)SiO 2 / 2The silyloxy group, T = formula (U)SiO 3 / 2 The silaneoxy unit, Q = SiO 4 / 2 The silyloxy group, M = (U)3SiO 1 / 2 The silaneoxy unit, and D = formula (U)₂SiO 2 / 2 The silyloxy unit, U, is as described above.

[0109] Preferably, the organopolysiloxane compound containing one or more alkene functional groups has an alkenyl unit weight content of 0.001%-30%, more preferably 0.01%-10%, and more preferably 0.02%-5%.

[0110] According to the invention, the unsaturated compound (A) reacts with a compound (B) containing at least one silyl functional group.

[0111] According to one embodiment, the compound (B) containing at least one silane functional group is a silane or polysilane compound containing at least one hydrogen atom bonded to a silicon atom. In this invention, a "silane" compound refers to a compound containing a silicon atom bonded to four hydrogen atoms or to an organic substituent. In this invention, a "polysilane" compound refers to a compound having at least one ≡Si-Si≡ unit.

[0112] Among silane compounds, the compound (B) containing at least one hydroxysilyl functional group can be a phenylsilane or a mono, di, or trialkylsilane, such as triethylsilane.

[0113] According to another embodiment, the compound (B) containing at least one hydroxysilyl functional group is an organopolysiloxane compound containing at least one hydrogen atom bonded to a silicon atom, also known as an organohydropolysiloxane. The organohydropolysiloxane may advantageously be an organopolysiloxane formed from the following units:

[0114] -At least two silyloxy units of the following formula:

[0115] H d U e SiO (4-d-e) / 2

[0116] in:

[0117] U is a monovalent hydrocarbon group having 1-12 carbon atoms, preferably selected from alkyl groups having 1-8 carbon atoms such as methyl, ethyl, or propyl, cycloalkyl groups having 3-8 carbon atoms, and aryl groups having 6-12 carbon atoms.

[0118] d = 1, 2, or 3, preferably d = 1 or 2; e = 0, 1, or 2; and d + e = 1, 2, or 3; and,

[0119] -Optionally, the other units of the following formula: U f SiO (4-f) / 2

[0120] Where U has the same meaning as described above, and f = 0, 1, 2 or 3.

[0121] It should be understood that in the above formula, if multiple groups U are present, they can be the same as or different from each other. Preferably, U can represent a monovalent group selected from: an alkyl group having 1-8 carbon atoms optionally substituted with at least one halogen atom such as chlorine or fluorine, a cycloalkyl group having 3-8 carbon atoms, and an aryl group having 6-12 carbon atoms. U can advantageously be selected from methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl, and phenyl.

[0122] In the above formula, the symbol d is advantageously equal to 1.

[0123] This organohydrogen polysiloxane can have a linear, branched, or cyclic structure. The degree of polymerization is preferably greater than or equal to 2. Typically, it is less than 5000.

[0124] When linear polymers are involved, they are essentially composed of a selection from the following formula: D:U₂SiO₃ 2 / 2 Or D':UHSiO 2 / 2 The silyloxy group of the unit and selected from the following formula M: U3SiO 1 / 2 or M':U2HSiO 1 / 2 The unit is composed of terminal silyloxy units, where U has the same meaning as described above.

[0125] Examples of organohydropolysiloxanes that may be compounds (B) containing at least one hydrosilyl functional group according to the present invention are:

[0126] - Poly(dimethylsiloxane) with a hydrogen dimethylsilyl terminus;

[0127] - Poly(dimethylsiloxane-co-methylhydrosiloxane) with trimethylsilyl terminus;

[0128] - Poly(dimethylsiloxane-co-methylhydrosiloxane) with a dimethylsilyl end;

[0129] - Poly(methylhydrosiloxane) with a trimethylsilyl terminus; and

[0130] - Cyclic poly(methylhydrosiloxane).

[0131] When organohydrogen polysiloxanes exhibit a branched structure, they are preferably selected from organosilicon resins of the following formula:

[0132] -M'Q, where the hydrogen atom bonded to the silicon atom is carried by the M group.

[0133] -MM'Q, where the hydrogen atoms bonded to silicon atoms are carried by a portion of the M units.

[0134] -MD'Q, where the hydrogen atom bonded to the silicon atom is carried by the D group.

[0135] -MDD'Q, where the hydrogen atoms bonded to silicon atoms are partially carried by the D group.

[0136] -MM'TQ, where the hydrogen atoms bonded to silicon atoms are carried by a portion of the M units.

[0137] -MM'DD'Q, where the hydrogen atoms bonded to silicon atoms are carried by a portion of the M and D units.

[0138] -and its mixtures,

[0139] Where M, M', D, and D' are defined as above, T: USiO 3 / 2 The silanoxy unit, and Q: SiO 4 / 2 The silyloxy unit, wherein U has the same meaning as described above.

[0140] Preferably, the organohydrogen polysiloxane compound has a weight content of 0.2%-91% of silyl Si-H functional groups, more preferably 3%-80%, and even more preferably 15%-70%.

[0141] According to a particular embodiment of the invention, the unsaturated compound (A) and the compound (B) containing at least one hydroxysilyl functional group can be the same compound, which on one hand contains at least one ketone functional group, at least one aldehyde functional group, at least one alkene functional group and / or at least one alkyne functional group, and on the other hand contains at least one silicon atom and at least one hydrogen atom bonded to the silicon atom. Such a compound may be referred to as "bifunctional" and is capable of reacting with itself via a hydrosilylation reaction. The invention also relates to a method for hydrosilylating a bifunctional compound with itself, the bifunctional compound on one hand containing at least one functional group selected from ketone, aldehyde, alkene and alkyne functional groups (preferably at least one alkene functional group and / or at least one alkyne functional group), and on the other hand containing at least one silicon atom and at least one hydrogen atom bonded to the silicon atom, the method being catalyzed by the iron complex (C) as described above.

[0142] Examples of organopolysiloxanes that can be bifunctional compounds include:

[0143] - Poly(dimethylsiloxane-co-hydromethylsiloxane-co-vinylmethylsiloxane) with dimethylvinylsilylterminus;

[0144] - Poly(dimethylsiloxane-co-hydromethylsiloxane-co-vinylmethylsiloxane) with dimethylhydrosilyl terminals; and

[0145] - Poly(dimethylsiloxane-co-hydromethylsiloxane-co-(propyl glycidyl ether)methylsiloxane) with a trimethylsilyl terminus.

[0146] When it comes to the use of an unsaturated compound (A) and a compound (B) containing at least one silyl functional group, those skilled in the art will understand that this also means the use of a bifunctional compound.

[0147] The amounts of compound (A) and compound (B) can be controlled such that the molar ratio of the silyl functional group of compound (B) to the alkene and alkyne functional groups of compound (A) is preferably 1:10 to 10:1, more preferably 1:5 to 5:1, and even more preferably 1:3 to 3:1.

[0148] The hydrosilylation reaction can be carried out in a solvent or in the absence of a solvent. In an alternative form, one of the reactants, such as the unsaturated compound (A), can act as a solvent. A suitable solvent is one that is miscible with compound (B). The hydrosilylation reaction can be carried out at temperatures of 15°C-300°C, preferably 20°C-240°C, more preferably 50°C-200°C, even more preferably 50°C-140°C, and still more preferably 50°C-100°C.

[0149] The molar concentration of the iron complex (C) can be from 0.01 mol% to 15 mol%, more preferably from 0.05 mol% to 10 mol%, even more preferably from 0.1 mol% to 8 mol%, relative to the total moles of unsaturation carried by the unsaturated compound (A). According to another alternative, without considering any possible solvents, the amount of iron used in the method of the present invention is 10 ppm to 3000 ppm, more preferably 20 ppm to 2000 ppm, and even more preferably 20 ppm to 1000 ppm, relative to the total weight of compounds (A), (B), and (C). According to a preferred alternative, in the method of the present invention, compounds based on platinum, palladium, ruthenium, or rhodium are not used. The amount of compounds based on platinum, palladium, ruthenium, or rhodium in the reaction medium relative to the weight of catalyst C is, for example, less than 0.1 wt%, preferably less than 0.01 wt%, and more preferably less than 0.001 wt%.

[0150] According to a preferred embodiment of the invention, compounds (A) and (B) used are selected from organopolysiloxanes as defined above. In this case, a three-dimensional network is formed, which leads to the curing of the composition. This crosslinking involves gradual physical changes in the medium constituting the composition. Therefore, the method according to the invention can be used to obtain elastomers, gels, foams, etc. In this case, crosslinked organosilicon materials are obtained. The term "crosslinked organosilicon material" refers to any silicone-based product obtained by crosslinking and / or curing a composition comprising an organopolysiloxane having at least two unsaturated bonds and an organopolysiloxane having at least three hydroxysilyl units. Crosslinked organosilicon materials can be, for example, elastomers, gels, or foams.

[0151] Still according to this preferred embodiment of the method of the present invention (where compounds (A) and (B) are selected from organopolysiloxanes as defined above), functional additives commonly used in organosilicon compositions can be used. As categories of commonly used functional additives, the following can be mentioned:

[0152] -filler,

[0153] - Adhesion accelerator,

[0154] - An inhibitor or delayer of the hydrosilylation reaction

[0155] - Adhesive modifier,

[0156] - Organosilicon resin

[0157] - An additive used to improve viscosity;

[0158] - Pigments; and

[0159] - Additives used for heat resistance, oil resistance, or flame retardancy, such as metal oxides. Detailed Implementation

[0160] Other details or advantages of the invention will become more apparent from the following embodiments, which are given in a purely indicative manner.

[0161] Example

[0162] Example 1: Synthesis of tris(trimethylsilyl)silyl potassium

[0163] 1 equivalent of ((CH3)3Si)4Si (5.00 g, 1.56 × 10⁻⁶ g) -2 (moles) and 1 equivalent of tert-butanol (1.75 g, 1.56 × 10⁻⁶). -2A molar amount of K[Si(SiMe3)3]·1.4THF was introduced into a 25 mL Schlenk tube. 5 mL of THF was added. The reaction was carried out at ambient temperature for 1 h 30, after which the solvent was evaporated under dynamic vacuum. After crystallization, washing, and drying, the product K[Si(SiMe3)3]·1.4THF was obtained in white crystalline form, with a yield of 82.8%.

[0164] Example 2: Synthesis of iron complex (THF)2Fe[Si(SiMe3)3]2 according to existing technology

[0165] The synthetic scheme described in S. Arata and Y. Sunada (Dalton Trans., 2019, 48, 2891-2895) was reproduced.

[0166]

[0167] FeBr2 (1.029 g, 4.77 × 10⁻⁶ g) was prepared in 20 ml of THF in a 100 ml Schlenk tube. -3 A suspension of (molar amounts) of K[Si(SiMe3)3]·1.4THF (3.700 g, 9.54 × 10⁻⁶ molars) obtained according to Example 1. -3 A mol of K[Si(SiMe3)3]·1,4THF solution was rapidly added dropwise to the FeBr2 suspension at ambient temperature. After reacting for 1 h, the deep purple solution was centrifuged at 3 °C for 10 min in a sealed PTFE tube under argon atmosphere to remove insoluble substances. After recovering the solution, the solvent was evaporated under dynamic vacuum. The resulting purple solid was then dissolved in 80 ml of pentane. The green solution was then centrifuged at 3 °C for 10 min in a sealed PTFE tube under argon atmosphere to remove insoluble substances. 5 ml of THF was added, and the solution was concentrated to about 15% of its initial volume and cooled to -30 °C. This yielded a complex (THF)2Fe[Si(SiMe3)3]2 in the form of purple crystals dried under vacuum after crystallization (yield: 83.0%).

[0168] Example 3: Synthesis of the iron complex (THF)2Fe[Si(SiMe3)3]2 according to the present invention

[0169] The purple crystals obtained in Example 2 were recrystallized according to the prior art (1.5 ml of pentane per 100 mg of crystals).

[0170] Therefore, according to the present invention, the complex (THF)2Fe[Si(SiMe3)3]2 is obtained with a recrystallization yield of 84% after recrystallization.

[0171] Analysis of the crystal obtained according to Embodiment 3 of the present invention shows that a crystal having the formula C has been obtained. 26 H 70FeO2Si8 with a molecular weight of 695.39 g.mol -1 The complex. By comparison, based on XRD analysis, the purple crystals obtained in the publications of S. Arata and Y. Sunada correspond to the complex with formula C. 34 H 70 FeO4Si8 with a molecular weight of 823.46 g·mol⁻¹ -1 The compound (see supporting information, Dalton Trans., 2019, 48, 2891-2895).

[0172] Examples 4-16: Crosslinking Test

[0173] In a glove box, the required weight of catalyst was weighed under an inert argon atmosphere and introduced into a dry, sealed flask. Subsequently, the organopolysiloxane was introduced into the flask under the same inert atmosphere, and the flask was then placed in a small metal container preheated to the required temperature (t=0). The gel time of the crosslinking experiment was qualitatively measured by the stirring-stop time (TAA). This TAA is related to the increase in viscosity to a point where the medium can no longer be stirred (equivalent to a viscosity of approximately 1000 mPa·s).

[0174] In Examples 4-9, the unsaturated compound is a poly(dimethylsiloxane) with a dimethylvinylsilyl terminus containing 1.1%-1.25% by weight of vinyl functional groups; the compound with a hydrosilyl functional group is a poly(methylhydrosiloxane) with a trimethylsilyl terminus containing 56% by weight of SiH functional groups; the SiH / SiVi molar ratio is 4; the amount of catalyst is 7 mol% (the molar percentage of iron provided by the catalyst relative to the number of moles of silicon-bonded vinyl groups provided by the unsaturated compound); and T is 30°C.

[0175] [Table 1]

[0176]

[0177] Under these experimental conditions, for reactions catalyzed by the catalysts of the present invention (Examples 7, 8, and 9) that had undergone a recrystallization step, the stirring stop time was between 1 h and 2 h. In the case of reactions conducted with prior art catalysts that had not undergone recrystallization (Examples 4, 5, and 6), poor reproducibility was observed, and the stirring stop time was between 2 h 40 h and 45 h.

[0178] These embodiments clearly demonstrate that the catalysts described in the prior art cannot produce the same technical results as the catalyst of the present invention. Therefore, they are physically different.

[0179] In Examples 10-16, the unsaturated compound is a poly(dimethylsiloxane) with a dimethylvinylsilyl terminus containing 1.1%-1.25% by weight of vinyl functional groups; the compound with a hydrosilyl functional group is a poly(methylhydrosiloxane) with a trimethylsilyl terminus containing 56% by weight of SiH functional groups; the SiH / SiVi molar ratio is 4; the catalyst is the recrystallized (THF)2Fe[Si(SiMe3)3]2 complex of Example 3; the amount of catalyst is 7 mol% (the molar percentage of iron provided by the catalyst relative to the number of moles of silicon-bonded vinyl groups provided by the unsaturated compound).

[0180] [Table 2]

[0181] Ex.10 30℃ 1h 30 Ex.11 40℃ 50 minutes Ex.12 50℃ 30 minutes Ex.13 60℃ 20 minutes Ex.14 70℃ 30 minutes Ex.15 80℃ 30 minutes Ex.16 90℃ 30 minutes

[0182] Examples 17-22: Functionalization Tests

[0183] In a glove box, under an inert argon atmosphere, weigh the required amount of catalyst and introduce it into a dry, sealed flask. First, introduce dodecane (0.3 g). Stir the medium to dissolve the catalyst. First, introduce the required amount of the compound with silyl functional groups, and then the required amount of the olefin into the flask. The flask is then placed in a small metal container preheated to the required temperature (t = 0).

[0184] The reaction medium was quantitatively analyzed by gas chromatography to determine the conversion rate and selectivity.

[0185] In Examples 17-22: the compound having a silyl functional group is 1,1,1,3,5,5,5-heptamethyl-3-hydrotrisiloxane (=MD'M); SiH / SiVi molar ratio = 1; catalyst: recrystallized (THF)2Fe[Si(SiMe3)3]2 complex of Example 3; catalyst amount = 0.5 mol% (molar percentage of iron provided by the catalyst relative to the number of moles of silicon-bonded vinyl groups provided by the unsaturated compound). (Vpdms = vinylpentamethyldisiloxane; Dvtms = divinyltetramethyldisiloxane).

[0186] [Table 3]

[0187]

Claims

1. A hydrosilylation method using a compound B containing at least one hydroxysilyl functional group and an unsaturated compound A containing at least one functional group selected from alkenes and alkynes, said method being catalyzed by an iron complex C represented by formula (1): Fe[Si(SiR3)3]2L n (1) in: - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms. - Each L represents an ether ligand independently, and - n = 1, 2 or 3.

2. The method of claim 1, wherein each R independently represents a group selected from alkyl, cycloalkyl, aryl, and aryl-alkyl groups, said groups optionally being substituted with one or more halogen atoms.

3. The method according to claim 1 or 2, wherein the ether ligand L is selected from formula R. 1 OR 2 The compound in which R 1 and R 2 Independent of each other, these represent substituted or unsubstituted hydrocarbon groups having 1-30 carbon atoms, which optionally contain one or more heteroatoms, or R 1 and R 2 Together with the oxygen atoms they are bonded to, they form cyclic hydrocarbon groups containing one or more heteroatoms.

4. The method according to claim 1 or 2, wherein the iron complex C is a compound of the following composition: 。 5. The method according to claim 1 or 2, wherein the unsaturated compound A is an organopolysiloxane compound containing one or more alkene functional groups.

6. The method of claim 1 or 2, wherein compound B, which contains at least one silyl functional group, is an organopolysiloxane compound containing at least one hydrogen atom bonded to a silicon atom.

7. A composition comprising at least one unsaturated compound A, at least one compound B, and a catalyst, wherein the unsaturated compound A comprises at least one functional group selected from alkene and alkyne functional groups, the compound B comprises at least one silyl functional group, and the catalyst is selected from an iron complex C represented by formula (1): Fe[Si(SiR3)3]2L n (1) in: - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms. - Each L represents an ether ligand independently, and - n = 1, 2 or 3.

8. A method for preparing the iron complex C represented by formula (1): Fe[Si(SiR3)3]2L n (1) in: - Each R independently represents a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms, which may optionally be substituted with one or more halogen atoms. - Each L represents an ether ligand independently, and - n=2 or 3; The method includes a step of preparing crude iron complex C, followed by a step of recrystallizing the crude iron complex C.

9. The iron complex C obtained or obtainable by the method defined in claim 8.

10. Use of the iron complex C according to claim 9 as a catalyst for the hydrogenation and silylation of olefins or alkynes.

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