Process for synthesizing silicone oligomers having sulfone moieties and silicon-containing compounds having sulfone moieties

Abstract

Provided herein is a process for the synthesis of sulfonylsilanes. Also provided herein are various sulfenylated and sulfonylated silicon-containing compounds made by the process.

Description

[Technical field]

[0001] CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 63 / 187,515, filed May 12, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a process for making sulfonylsilanes, which can be used in a variety of commercial and industrial applications. [Background technology]

[0003] Non-aqueous solvents are used in the electrolyte compositions of lithium-ion (Li-ion) batteries. These solvents are susceptible to decomposition due to the presence of electrochemical potential during the charge-discharge cycle of the battery. However, certain additives are known to prevent such decomposition when added to the electrolyte composition. Such additives are believed to form a solid electrolyte interface (SEI) layer on the electrode, imparting stability to the electrode and preventing the dissolution of transition metal ions into the electrolyte composition. One group of such SEI layer-forming electrolyte additives are sulfonylsilanes.

[0004] Conventional processes for synthesizing sulfonylsilane electrolyte additives do not provide the desired yields and / or are cost intensive and therefore not commercially viable. For example, one conventional synthetic route for making sulfonylsilanes uses a hydrosilylation reaction, which has the disadvantage of requiring a platinum catalyst, which is costly and does not provide the desired results.

[0005] Thus, there is a need for intermediates and processes for the synthesis of sulfonylsilanes that can produce electrolyte additives for lithium ion batteries in high yields and in a more cost-effective manner. Summary of the Invention

[0006] The present inventors have surprisingly found a process for forming sulfonyl silicon-containing materials such as sulfonylsilanes at greater purity and at lower cost compared to conventional hydrosilylation reaction processes for making sulfonylsilanes. In particular, it has been unexpectedly found that the first Si-C bond formation with a sulfenyl metal intermediate followed by the oxidation of the silane (i.e., the formation of a sulfone moiety) is important to avoid intramolecular reactions that form isomeric by-products, and also results in a reduced-cost process for the production of sulfonylsilanes. In fact, in the process described herein, it is possible to completely omit the hydrosilylation catalyst. In addition, the applicant has demonstrated that the specific sequence of steps described above, the formation of the Si-C bond followed by oxidation, would result in no product being obtained if the above-mentioned specific sequence of steps were reversed.

[0007] Provided herein is a process for the synthesis of sulfonylsilane(s): Compounds of formula (I): X-(R * ) n -SR (I) with a metal (M) selected from the group consisting of Li, Na, Mg, Al, Cs, Sn, Ni and Hg to produce a sulfenyl metal intermediate of formula (II): (X) a -M-[(R * ) n -SR] b (II) and converting the sulfenyl metal intermediate (II) into a silane of formula (III): Si(X)2(R 1 )2(III) to obtain a sulfenylated silicon-containing reaction product; and contacting the sulfenylated silicon-containing reaction product with an oxidizing agent, where X is a halogen selected from the group consisting of Cl, Br, and I; each subscript n is an integer from 1 to about 10; each R is H or a monovalent organic radical having from 1 to about 12 carbon atoms and optionally having one or more heteroatoms such as O, N, or S; R * each is a divalent organic group having from 1 to about 8 carbon atoms and optionally having one or more heteroatoms such as O, N, or S; and R 1 each is a monovalent organic radical having 1 to about 12 carbon atoms and optionally having one or more heteroatoms such as O, N, or S; the subscript a is 0 or 1; and the subscript b is an integer from 1 to about 10, with the proviso that when a is 0, b is 1 to about 10, and when a is 1, b is 1.

[0008] In one embodiment, X is Cl, each subscript n is an integer from 2 to 6, each R is H or a monovalent alkyl group of 1 to about 4 carbon atoms, and R * each is a divalent alkyl group having 1 to about 6 carbon atoms and optionally having one or more heteroatoms such as O, N or S; R 1 each is a monovalent alkyl group of 1 to about 4 carbon atoms, the subscript a is 0 or 1; and the subscript b is an integer from 1 to about 10, with the proviso that when a is 0, b is 1 to about 10, and when a is 1, b is 1.

[0009] In one embodiment, X is Cl, each subscript n is an integer from 2 to 4, each R is independently H, methyl, ethyl or propyl, and R * each is a divalent alkyl group of 1 to about 4 carbon atoms; R 1 each is a monovalent alkyl group of 1 to about 4 carbon atoms, the subscript a is 0 or 1; and the subscript b is an integer from 1 to about 10, with the proviso that when a is 0, b is 1 to about 10, and when a is 1, b is 1.

[0010] In one embodiment, X is Cl, each subscript n is an integer from 2 to 4, each R is independently H, methyl, ethyl or propyl, and R * Each of R is -(CH2)-; 1 is methyl, the subscript a is 0 or 1; and the subscript b is an integer from 1 to about 10, with the proviso that when a is 0, then b is 1 to about 10, and when a is 1, then b is 1.

[0011] In the present application, the formula (IV): Q-Si(R 1 )2-(R * ) n -SR (IV) wherein Q is a halogen selected from the group consisting of Cl, Br and I; or a sulfenylated silicon-containing compound of the formula -(R * ) n or a moiety of the formula -O-[Si(R 1 )2-O] y -Si(R 1 )2-(R * ) n -SR part, and where R 1 , R * and R are each as defined above, and where each subscript n is an integer from about 1 to about 10, and y is an integer from 1 to about 10. In one embodiment, y is an integer from 1 to 3.

[0012] In the present application, the formula (VI): Q * Si(R 1 )2-(R * ) n -S(=O)2-R (VI) A sulfonylated silicon-containing compound of the formula: * Q 2* or Q 3* where Q 2* is the formula -(R * ) n -S(=O)2-R moiety; and Q 3* is represented by the formula -O-[Si(R1 )2-O] y -Si(R 1 )2-(R * ) n -S(=O)2-R moiety, where R 1 , R * and R are as defined above, and each of the subscripts n and y are as defined above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the specification and claims of this application, the following terms and expressions shall be understood as set forth below.

[0014] The singular forms "a," "an," and "the" include the plural and reference to a particular value includes at least that particular value unless the context clearly indicates otherwise.

[0015] The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended merely to more clearly illustrate the invention and does not pose limitations on the scope of the invention unless specifically stated otherwise.

[0016] The terms "comprising," "including," "containing," "characterized by," and their grammatical equivalents are understood to be inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps, and include the more restrictive terms "consisting of" and "consisting essentially of."

[0017] No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0018] Furthermore, all compounds, materials or substances explicitly or implicitly disclosed and / or claimed herein as belonging to a group of structurally, compositionally and / or functionally related compounds, materials or substances are understood to include the individual members of that group and all combinations thereof.

[0019] Other than in the examples, or unless otherwise noted, all numbers expressing quantities of ingredients, reaction conditions, lengths of time, quantified properties of substances, and the like described in this specification and claims, whether or not the term "about" is used in the description, are understood to be modified in all instances by the term "about."

[0020] In one embodiment herein, any numerical range described herein is understood to include all subranges within that range, and any combination of the various endpoints of such ranges or subranges, whether or not they are described in the examples or elsewhere herein.

[0021] It is also understood herein that any of the components of the invention described by any particular genus or species, or detailed in the Examples section herein, can in one embodiment be used to define an alternative definition for any of the endpoints of the ranges set forth elsewhere in the specification for that component, and thus, in one non-limiting embodiment, can replace the endpoints of the ranges set forth elsewhere.

[0022] Reference is made to a material, component, or ingredient that is present and formed in situ, blended, or mixed at a time immediately prior to first contacting with one or more other materials, components, or ingredients in accordance with this disclosure. A material, component, or ingredient identified as a reaction product, resulting mixture, or otherwise, may acquire identity, properties, or characteristics through chemical reaction or modification during the course of the contacting, in situ forming, blending, or mixing operation, performed in accordance with this disclosure and applying common knowledge and the ordinary skill of one of ordinary skill in the relevant art (e.g., chemical engineers). The modification of chemical reactants or starting materials into chemical products or final materials is a continuously evolving process, independent of the rate at which it occurs. Thus, as such modification processes proceed, there is a mixture of starting and final materials, and possibly intermediate species that, depending on their thermodynamic lifetimes, may be easier or more difficult to detect with current analytical techniques known to those of ordinary skill in the art.

[0023] Reactants and components referenced in the specification or claims of this application by chemical name or formula, whether referred to in the singular or plural, may be identified as existing prior to contact with another material (e.g., another reactant or solvent) referenced by chemical name or species. Any preliminary and / or transitional chemical changes, modifications, or reactions occurring in the resulting mixture, solution, or reaction medium may be identified as intermediate species, masterbatches, or the like, and may have a utility separate from that of the reaction product or final material. Other subsequent changes, modifications, or reactions may result from combining the identified reactants and / or components together under the conditions required in accordance with this disclosure. In such other subsequent changes, modifications, or reactions, the reactants, components, or building blocks that are combined together may identify or designate the reaction product or final material.

[0024] The expression "organic group" as used herein is understood as any aliphatic group, such as linear or branched alkyl, linear or branched alkenyl, containing up to 60 carbon atoms, aryl, aralkyl, cycloalkyl and others, which may optionally contain at least one heteroatom and / or different heteroatom groups in each of the organic groups described herein.

[0025] The term "alkyl" refers to any monovalent saturated straight, branched, or cyclic hydrocarbon radical. Non-limiting examples of alkyl include methyl, ethyl, isopropyl, propyl, butyl, and isobutyl.

[0026] The expression sulfenylated silicon-containing reaction products should be understood to include both sulfenylated silane compounds and sulfenylated silicone compounds.

[0027] This invention describes a method to create Si-C bonds with heterofunctional groups, such as sulfenyl and sulfone. The final products (telechelic silanes and siloxanes with sulfone groups) are intermediates for the formation of additives, which can have applications as additives in the field of Li-ion batteries.

[0028] In one specific non-limiting embodiment herein, a halo-bromoalkane is reacted with a metal alkylsulfide to form 1-chloro-3-methylsulfanyl-propane, followed by reaction with Mg and then reaction with dimethyldichlorosilane to form chloro-dimethyl-(3-methylsulfanylpropyl)silane). In one or more embodiments, Mg can be replaced by one of Li, Na, Al, Cs, Sn, Ni, and Hg.

[0029] The reaction of chloro-dimethyl-(3-methylsulfanylpropyl)silane) with water leads to the formation of telechelic siloxanes having methylsulfanylpropane functionality which when oxidized leads to the formation of telechelic methylsulfonylpropane siloxanes.

[0030] In one embodiment of the present application, the process of the present invention can be described by the following reaction scheme of steps (a), (b), optional step (b-1) and (c), with preferred species shown immediately below the general formula: [ka] [ka] [ka] [ka]

[0031] Formulas (I), (II), (III), (IVa), (IV), (V) and (VI) described herein can be understood by reference to the reaction steps (a), (b), (b-1) and (c) described above in a non-limiting manner. It will be understood that in the processes described herein, the contacting step (b) must precede the oxidation step (c). In the above formulas, X is a halogen selected from the group consisting of Cl, Br and I; each of the subscripts n is an integer from 1 to about 10; each of R is H or a monovalent organic group having 1 to about 12 carbon atoms; R * each is a divalent organic group having from 1 to about 8 carbon atoms, and R 1each is a monovalent organic radical having 1 to about 12 carbon atoms; the subscript a is 0 or 1; and the subscript b is an integer from 1 to about 10, with the proviso that when a is 0, b is 1 to about 10, and when a is 1, b is 1.

[0032] In one particular embodiment, compound (I) in step (a) of the process described herein can be prepared by any suitable commercial process. However, in one preferred embodiment, compound (I) is a brominated organohalogen compound of the general formula (Ia): XR * -Br (Ia) and an alkali metal thioalkoxide of formula (Ib): YSR (Ib) where X is a halogen selected from the group consisting of Cl, Br and I, preferably Cl, and R *is as defined above, and most preferably formula (Ia) is 1-bromo-3-chloropropane, and where Y is an alkali metal, non-limiting examples of which are Li, Na, and K, preferably Na, and R is as defined above, and most preferably formula (Ib) is sodium thiomethoxide. Preferably, the reaction is carried out in a molar ratio of compound (Ia) to compound (Ib) ranging from about 0.5:2.0 to about 2.0:0.5, more preferably at about an equimolar ratio. Preferably, the reaction is carried out at a temperature of about 20° C. to about 30° C., and preferably at about room temperature. Each of the steps of the processes described herein can be carried out solvent-free or in the presence of organic solvents, non-limiting examples of which include alkane solvents such as hexane, heptane, dodecane, and the like; cyclic alkanes such as cyclopentane, cyclohexane, and cyclooctane; furan solvents such as tetrahydrofuran; aromatic solvents such as toluene; acetal solvents such as dioxane; ester solvents such as ethyl acetate; nitrile solvents such as acetonitrile; glycol solvents such as ethylene glycol dimethyl ether; ether solvents such as diethyl ether, diisopropyl ether, diphenyl ether, polyethylene glycol alkyl ether; sulfide solvents such as dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide; sulfoxide solvents such as dimethyl sulfoxide; cyclic amide solvents such as N-methylpyrrolidone; formamide solvents such as N,N-dimethylformamide; imidazole solvents such as methylimidazole and dimethylimidazole; ketone solvents such as acetone, methyl ethyl ketone, and most preferably toluene. In addition, the reaction of (Ia) and (Ib) can optionally be carried out in the presence of a phase transfer catalyst of the type known to those skilled in the art, one non-limiting example of which is tetrabutylammonium bromide. The reaction can be carried out for any suitable length of time, but is preferably carried out for a length of time from 1 hour to 12 hours, preferably from 2 hours to 8 hours.

[0033] The compound of formula (Ia) above can also be present in the above-described reaction scheme steps, preferably as an unreacted reactant in the reaction of formulas (Ia) and (Ib) above, as a reaction initiator in reaction step (a) described herein. Preferably, the compound of formula (Ia) can be present in an amount of up to about 2% by weight based on the weight of the reactants in step (a) of the process described herein, and more preferably reaction step (a) can include up to about 2% by weight of chlorobromopropane. In certain circumstances, the addition of the compound of formula (Ia) can result in an exotherm in reaction step (a), which can be controlled by repeated stepwise additions as described herein and conventional cooling techniques such as dry ice. In some embodiments, the repeated additions are carried out by injecting the intermediate dropwise. In one embodiment of the present application, any one or more of the process steps described herein, particularly (a), (b), (b-1) and (c), are optionally carried out in the presence of at least one initiator selected from the group consisting of dihaloalkanes, metal iodides and iodine, and compounds of formula (Ia), most preferably chlorobromopropane, which can be added all at once or dropwise to the reaction mixture.

[0034] Reacting step (a) can involve reacting compound (I) with a metal (M), which can include one or more of the metals described herein. Such metals can be present in elemental form and / or in an organic compound. In one embodiment, the metal M can be a Grignard reagent. In one embodiment, the metal is magnesium. In some embodiments, compound (I) is a 1-bromo-3-haloalkane. In one embodiment, compound (I) is 1-bromo-3-chloropropane. The reaction of compound (I) with metal M can be carried out in an organic solvent, such as THF and / or xylene, as described herein, at a temperature of about 60° C. to about 80° C. In one or more embodiments, the temperature is about 65° C. to about 80° C., and in some other embodiments, the temperature is about 75° C. In some embodiments, the molar ratio of compound (I) to metal M is about 0.5:2.0 to 2.0:0.5. In some other embodiments, the molar ratio of compound (I) to metal M is about equimolar. The reaction can be carried out for any suitable length of time. In some embodiments, the reaction can be carried out for a length of time of about 10 minutes to about 2 hours, and in some embodiments, the reaction can be carried out for a length of time of about 30 minutes to 1.5 hours. As described above, reaction step (a) can be carried out in the presence of up to about 2% by weight of chlorobromopropane as an initiator. In some embodiments, the addition of compound (I) to metal M is carried out dropwise over an extended period of time, such as the length of time described herein above.

[0035] Reaction step (a) produces the sulfenylmetal intermediate (II) described hereinabove. In one embodiment of formula (II), when subscript a is 0, subscript b is 1, resulting in a difunctional or higher functionality sulfenylmetal intermediate. In an alternative embodiment, when a is 1, subscript b is 1, and the compound of formula (II) is a sulfenylmetal halide intermediate.

[0036] The sulfenyl metal intermediate (II) of step (a) is then reacted in step (b) with a sulphenyl metal intermediate (II) to form a Si-C bond, i.e. with a compound of general formula (IVa): Q-Si(R 1 )2-(R * ) n -SR (IVa) and a silane of formula (III) as described above to obtain a sulfenylated silicon-containing reaction product of formula (III), where Q is Q 1 or Q 2 And here Q 1 is a halogen selected from the group consisting of Cl, Br and I; and Q 2 is the formula -(R * ) n -SR part; and where R 1 , R * and R are each defined as above, and more preferably R and R 1 are each methyl, and R * Each of Q is -(CH2)- and each of the subscripts n is an integer from 1 to 10, in some embodiments from 2 to 8, and in some other embodiments from 2 to 4. In some embodiments, the silane of general formula (III) above used in step (b) is dimethyldichlorosilane. In some embodiments, Q 1 is Cl.

[0037] In a non-limiting embodiment of step (b), the sulfenyl metal intermediate (II), in one embodiment a sulfenyl metal halide intermediate (II), is contacted with the silane of formula (iii) by repeated addition of the sulfenyl metal intermediate (II) to the silane (III), for example by dropwise injection of the sulfenyl metal intermediate (II) to the silane (III).

[0038] In some embodiments, the reaction can be carried out in the presence of an organic solvent(s) as described herein above, such as THF and / or xylene.

[0039] In a non-limiting embodiment of step (b), the sulfenyl metal intermediate (II) is contacted with a silane of formula (III), where the silane of formula (III) is present in a stoichiometric molar excess relative to the sulfenyl metal intermediate of formula (II).

[0040] In one embodiment of step (b), the molar ratio of compound (III) to compound (II) is generally a molar excess, such as a molar excess of about 2:1 to about 7:1, although equimolar ratios are also contemplated. The use of a molar excess of the sulfenyl metal intermediate (II) described above and / or the use of the sulfenyl metal intermediate (II) described above can result in the formation of a silane dimer form of formula (IVa), i.e., Q is a silane dimer of formula -(R * ) n Reaction step (b) may be carried out at a temperature from -5°C to about 10°C, and in one embodiment at about 0°C, and may be carried out for any suitable length of time, but in one embodiment from about 30 minutes to about 3 hours, and in one embodiment from about 1 to 2 hours.

[0041] However, although not required for the processes described herein, in certain embodiments, the sulfenylated silicon-containing reaction product (IVa) has a structure in which Q is Q 1 In an embodiment, the reaction step (b-1) is optionally contacted with water. The amount of water to reaction product (IVa) is generally in the range of a molar ratio of 0.5:1 to about 2.0 molar amount, and in one embodiment, the amount of reaction product (IVa) is about equimolar to the water. Reaction step (b-1) is carried out by reacting a compound of the general formula (V): RS-(R * ) n -Si(R 1 )2-O-[Si(R 1 )2-O] x -Si(R 1 )2-(R * ) n -SR (V) where R, R * and R 1are as defined herein, and each n is as defined herein, and the subscript x is an integer from 0 to 10, in some embodiments from 1 to 8, and in some embodiments from 1 to 4. Reacting step (b-1) can be carried out at about room temperature and for a suitable length of time, such as from about 10 minutes to about 2 hours, and in one embodiment from about 30 minutes to about 1 hour. The use of water in reacting step (b-1) results in the formation of a siloxane (dimer) of formula (V), which then acts with compound (IVa) or alone (depending on the amount of hydrolysis that occurs in step (b-1)) during reacting step (c).

[0042] Following step (b), step (b-1), compound (IVa), if present, and compound (V), if present, can be treated with a base, optionally prior to step (c). Suitable bases can include any commercially available base, such as ammonia, amines, metal hydroxides, e.g., NaOH and the like. The amount of base used can be determined by one of skill in the art, but should generally provide a pH of about 5 to 8, and in some embodiments about 7, for the reaction product of steps (b) and / or (b-1).

[0043] The sulfenylated silicon-containing reaction product (IVa), and, if present, the sulfenylated siloxane reaction product (V), are then contacted with an oxidizing agent in step (c) to produce a sulfenylated silicon-containing reaction product having the general formula (VI): Q * -Si(R 1 )2-(R * ) n -S(=O)2-R (VI) where Q is a sulfonylated silicon compound of formula * Q 2* or Q 3* where Q 2* is the formula -(R * ) n -S(=O)2-R moiety; and Q 3* is represented by the formula -O-[Si(R 1 )2-O] y-Si(R 1 )2-(R * ) n -S(=O)2-R moiety, where R 1 , R * and R are as defined herein above, and subscripts n and y are as defined herein.

[0044] Suitable oxidizing agents include oxygen, ozone, hydrogen peroxide, and organic peroxides. Oxidation may be carried out using ozone / nascent oxygen [O], and hydrolysis may be avoided. In the presence of ozone, only oxides are formed without by-products. In the presence of hydrogen peroxide, the Si-Cl bond is completely hydrolyzed.

[0045] Reacting step (c) can be carried out in the presence of any suitable oxidation catalyst, a non-limiting example of which is sodium tungstate dihydrate. Reacting step (c) can also be carried out in the presence of any organic solvent described herein, which in some embodiments is acetonitrile. Reacting step (c) can be carried out at a temperature of about 65° C. to about 80° C., preferably about 70° C. to about 75° C., and for a length of time of about 1 hour to about 8 hours, preferably about 2 hours to 4 hours. The amount of compound (IV) and / or (V) to the oxidizing agent can generally range from about 0.5:2 to about 2.0:0.5, and is preferably an equimolar amount.

[0046] The purity of the sulfonylated silicon-containing compound of formula (VI), following purification of the reaction product (VI), which in some embodiments can be carried out using conventional purification techniques such as decantation, extraction, distillation, and the like, can be greater than about 90% by weight, in some embodiments greater than 95% by weight, and in some embodiments up to about 99% by weight, each of these ranges being based on the total weight of the reaction product mixture of step (c).

[0047] The sulfonylated silicon compound of general formula (VI) can then be further reacted as known in the art to produce various commercially suitable materials, including but not limited to the use of the sulfonylated silicon compound of general formula (VI) in electrolyte compositions and electrolyte compositions for Li-ion electricity. Any of the other compounds of the formulas described herein can also be used in the electrolyte compositions. Working Example

[0048] Example 1: Synthesis of sulfide precursor (2): [ka] In a 3 L, 3-neck round bottom flask equipped with an overhead stirrer and an addition funnel, 1-bromo-3-chloropropane (1) (500 g, 3.18 moles) was added to 235 grams of toluene. Tetrabutylammonium bromide (25 g, 0.08 moles) was added as a phase transfer catalyst. The mixture was cooled to 24°C in an oil bath. A 21% aqueous solution of sodium thiomethoxide (1058 g, 3.17 moles) was added dropwise to the reaction mixture over a period of 3 hours at 10-30°C with constant stirring. The reaction temperature was maintained at the same temperature for another 2 hours. The organic and aqueous fractions were separated using a separatory funnel. Again tetrabutylammonium bromide (7 g, 0.02 moles) and a 21% aqueous solution of sodium thiomethoxide (160 g, 0.48 moles) were added dropwise to the reaction mixture over a period of 2 hours at 10-30°C with constant stirring. The reaction temperature was maintained at the same temperature for an additional 2 hours. The organic fraction was washed with water (200 ml) and combined with the aqueous fraction with toluene (50 ml). Toluene was removed from the organic fraction under reduced pressure and the crude product was purified by fractional distillation to remove unreacted starting materials. Pure 1-chloro-3-methylsulfanyl-propane 95% (2) was obtained as a colorless liquid at 0 mbar and 56° C. along with by-products di(methylsulfanyl)propane 3% and 2% chlorobromopropane. It has been found that typically up to 2% chlorobromopropane is required in the mixture as it acts as an initiator during the reaction.

[0049] Formation of a sulfenyl metal intermediate (step (a)) followed by reaction with dimethyldichlorosilane (step (b)) and then contact with water (step (b-1)) mechanism: [ka]

[0050] Reaction procedure: Magnesium (23 g, 0.95 mol) was weighed into a 2 L dry 4-neck round bottom flask equipped with a condenser, addition funnel and magnetic stir bar. The reaction set-up was flushed with nitrogen. 160 ml of anhydrous tetrahydrofuran and 400 ml of xylene were added to the reaction vessel under nitrogen atmosphere. 100 g (0.80 mol) of 1-chloro-3-methylsulfanyl-propane (2) was placed into the addition funnel. The reaction mixture was heated to 65° C. and ∼15% of 1-chloro-3-methylsulfanyl-propane (2) was added to the magnesium with constant stirring. No exotherm was observed at this point. The reaction temperature was then increased to 75° C. and 1-bromo-3-chloropropane (3.2 g, 0.02 mol) was added in one portion to the reaction mixture. An exotherm of 20° C. was observed at this point. The exotherm was controlled by cooling with dry ice, lowering the temperature to ∼70° C. At this temperature, the remaining 1-chloro-3-methylsulfanyl-propane (2) was added dropwise with constant stirring. The reaction temperature was maintained near 75°C by simultaneously controlling the rate of addition and cooling. As the reaction proceeded, the color of the reaction mixture changed to a grayish color, confirming the formation of a sulfenyl metal intermediate. After the addition was complete, the reaction mixture was stirred at 75°C for an additional hour. Heating was then discontinued and the solution was allowed to cool to room temperature under a nitrogen atmosphere. Simultaneously, another 2 L, dry, 4-neck round bottom flask was set up with an overhead stirrer and addition funnel and flushed with nitrogen. The solution was transferred to the addition funnel using a cannula. Dimethyldichlorosilane (310 g, 2.4 mol) and 400 ml of xylene were placed in the second round bottom flask under a nitrogen atmosphere. The solution was cooled to ~0°C and the solution was added dropwise with constant stirring. As the addition proceeded, magnesium chloride was seen to gradually precipitate. After the addition was complete, the reaction mixture was held at the same temperature for an additional 2 hours. The reaction mixture was then allowed to warm to room temperature and stirred under nitrogen for 2 hours. THF and unreacted dimethyldichlorosilane were then removed from the reaction mixture under reduced pressure (~11 mbar, 55°C). 1H-NMR analysis suggested the formation of Si-C bonds, as indicated by multiplets at ∼1.1 ppm and ∼1.9 ppm (Figure 1). TIFF2024517932000007.tif107163 FIG. 1: Reaction mixture of step b in CDCl3 1 H-NMR spectrum

[0051] Step (c): Oxidation of chloro-dimethyl-(3-methylsulfanylpropyl)silane (4) and higher analogues (5) mechanism: [ka]

[0052] Reaction procedure: The organic fraction from the previous step was transferred to a 2 L, 3-neck round bottom flask equipped with a condenser, an addition funnel and a magnetic stir bar. 250 ml of acetonitrile was added to the reaction mixture. Sodium tungstate dihydrate (5 g, 15 mmol) was dissolved in 40 ml of water and added to the reaction mixture. A 30% aqueous solution of hydrogen peroxide (220 g, 1.94 mol) was placed in the addition funnel. The reaction mixture was heated to 70° C. and hydrogen peroxide was added dropwise over a period of 2 hours with constant stirring. An exotherm was observed during the addition of hydrogen peroxide. The reaction temperature was maintained near 75° C. by cooling and slow addition. After completion of the addition, the reaction mixture was stirred at the same temperature for an additional 3 hours. Then, acetonitrile was removed from the reaction mixture under reduced pressure and the organic fraction was separated from the aqueous phase using a separatory funnel. The aqueous fraction was extracted with ethyl acetate (2 x 100 ml) and the material recovered by stripping the solvent was added to the organic fraction. 1 H-NMR analysis showed complete oxidation of the starting material to the sulfone derivatives of the siloxane dimers and higher analogues (6). The organic fraction was used directly in the next step.

[0053] Comparative Example 1: Oxidation of Sulfides and Subsequent Treatment with Dimethyldichlorosilane and Magnesium Step 1: Oxidation of 1-chloro-3-methylsulfanyl-propane (2) [ka]

[0054] Procedure: 1-Chloro-3-methylsulfanyl-propane (10 g, 80 mmol) was placed in a 250 ml three-neck round bottom flask equipped with a condenser, an addition funnel and a magnetic stir bar. Xylene (50 ml) and acetonitrile (50 ml) were added to the flask. Sodium tungstate (0.5 g, 1.5 mmol) was dissolved in 2 ml of water and added to the reaction mixture. The reaction mixture was heated to 75° C. and 30% aqueous hydrogen peroxide solution (20.7 g, 200 mmol) was added dropwise with constant stirring. The reaction mixture was stirred at the same temperature for 3 hours. Afterwards, acetonitrile was removed from the reaction mixture under reduced pressure. The xylene fraction was separated from the aqueous fraction and the solvent was removed using a rotary evaporator. 1 H-NMR analysis showed complete oxidation of the starting material to 1-chloro-3-methylsulfonyl-propane.

[0055] Step 2: Reaction of magnesium with 1-chloro-3-methylsulfonyl-propane [ka]

[0056] Procedure: Magnesium (340 mg, 14 mmol) was placed in a 100 ml 3-neck round bottom flask equipped with a condenser. The reaction set-up was flushed with nitrogen and anhydrous THF (40 ml) and xylene (40 ml) were added to the reaction vessel under nitrogen atmosphere. 1-Chloro-3-methylsulfonyl-propane (2 g, 12.8 mmol) was added dropwise to the reaction mixture at 75° C. No exotherm was observed. The reaction was left overnight under nitrogen atmosphere with stirring at the same temperature. The circulating magnesium was seen to disappear, indicating metal insertion. In another 250 ml round bottom flask flushed with nitrogen, dimethyldichlorosilane (2.4 g, 19.2 mmol) and xylene (40 ml) were placed. The reaction mixture was cooled to 0° C. At the same temperature, the reaction mixture from the first reaction vessel was added dropwise using a syringe. The mixture in the second vessel was stirred at 0° C. for 1 hour and then allowed to warm to room temperature. 1 H-NMR analysis suggested that no Si–C bonds were formed due to the lack of distinct multiplets at ∼1.1 and 1.9 ppm (Figure 2). JPEG2024517932000011.jpg87149 FIG. 2: Reaction mixture after step 2 of the comparative example (treatment step with silane and Mg after oxidation) 1 H-NMR JPEG2024517932000012.jpg91146 Figure 3: Comparison of the reaction mixture after reaction of Example 1 (upper spectrum) and Comparative Example 1 (lower spectrum). In the case of Comparative Example 1, oxidation of the sulfide to sulfone is carried out prior to treatment with silane and Mg. In the Comparative Example, no C-Si bonds are formed as indicated by the lack of multiplets at ∼1.1 ppm and 1.9 ppm.

[0057] While the present invention has been described in terms of certain embodiments, those skilled in the art will recognize that various changes may be made in the components thereof and equivalents may be substituted without departing from the spirit of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the invention, and the invention includes all embodiments falling within the scope of the appended claims.

Claims

1. 1. A process for the synthesis of sulfonylsilanes comprising: (a) A compound of formula (I): X-(R*) ｎ -S-R (I) with a metal (M) selected from the group consisting of Li, Na, Mg, Al, Cs, Sn, Ni and Hg to produce a sulfenyl metal intermediate of formula (II): () ａ _ * * ) ｎ _____ ｂ (=) Get (b) reacting the sulfenyl metal intermediate (II) with a silane of formula (III): If (X) ２ (R １ ) ２ (III) to obtain a sulfenylated silicon-containing reaction product; and (c) contacting the sulfenylated silicon-containing reaction product with an oxidizing agent; where X is a halogen selected from the group consisting of Cl, Br, and I; each of the subscripts n is an integer from 1 to about 10; each of the R's is H or a monovalent organic radical having 1 to about 12 carbon atoms; each of the R*'s is a divalent organic radical having 1 to about 8 carbon atoms; and R １ each of which is a monovalent organic group having 1 to about 12 carbon atoms; subscript a is 0 or 1; and subscript b is an integer from 1 to about 10, with the proviso that when a is 0, then b is 1 to about 10, and when a is 1, then b is 1.

2. The sulfenylated silicon-containing reaction product of step (b) has the formula (IVa): Q-Si(R １ ) ２ -(R*) ｎ -S-R (IVa) where Q is Q １ Or Q ２ where Q １ is a halogen selected from the group consisting of Cl, Br and I; and Q ２ is the formula -(R*) ｎ The process of claim 1, wherein the moiety is -S-R.

3. 3. The process of claim 2, wherein Q is a halogen selected from the group consisting of Cl, Br and I.

4. Q is the formula -(R*) ｎ The process of claim 2, wherein the moiety is -S-R.

5. R and R １ are each methyl, and each R* is -(CH ２ 3. The process of claim 2, wherein each n is an integer from about 2 to about 4.

6. 3. The process of claim 1 or 2, wherein in step (b) the sulfenyl metal intermediate of formula (II) is contacted with a silane of formula (III), wherein the silane of formula (III) is present in a stoichiometric molar excess relative to the sulfenyl metal intermediate of formula (II).

7. 3. The process of claim 1 or 2, wherein in step (b) the sulfenyl metal intermediate (II) is contacted with the silane of formula (III) by repeated addition of the sulfenyl metal intermediate of formula (II) to the silane of formula (III).

8. 8. The process of claim 7, wherein the repeated addition is accomplished by dropwise injection of the sulfenyl metal intermediate of formula (II) to the silane of formula (III).

9. 3. The process of claims 1 or 2, wherein the sulfenylated silicon-containing reaction product of step (b) is a sulfenylated silane which is contacted with water to form a sulfenylated siloxane prior to step (c).

10. The sulfenylated siloxanes are represented by the general formula (V): R-S- (R*) ｎ -Si(R １ ) ２ -O-[Si(R １ ) ２ -O] ｘ -Si(R １ ) ２- -(R*) ｎ -S-R (V) where R and R １ 10. The process of claim 9, wherein each of R* is independently a monovalent aliphatic radical of 1 to 12 carbon atoms, each R* is a divalent organic radical of 1 to 8 carbon atoms, each subscript n is an integer from 1 to about 10, and each subscript x is an integer from 0 to 10.

11. 3. The process of claims 1 or 2, wherein the sulfenylated silicon-containing reaction product of step (b) is a sulfenylated silane, which is treated with a base prior to step (c).

12. 3. The process of claim 1 or 2, wherein the oxidizing agent in step (c) is selected from the group consisting of oxygen, ozone, hydrogen peroxide, and organic peroxides.

13. 3. The process of claim 1 or 2, wherein one or more of steps (a), (b) or (c) of the process is carried out in the presence of an initiator.

14. 14. The process of claim 13, wherein the initiator is selected from the group consisting of dihaloalkanes, metal iodides and iodine.

15. A sulfenylated silicon-containing compound of formula (IV): Q-Si(R １ ) ２ -(R*) ｎ -S-R (IV) where Q is a halogen selected from the group consisting of Cl, Br and I; or a halogen atom of the formula -(R*) ｎ or a moiety of the formula -O-[Si(R １ ) ２ -O] ｙ -Si(R １ ) ２ -(R*) ｎ -S-R moiety, where R １ each of R* is a divalent organic radical having 1 to about 8 carbon atoms, each of R is H or a monovalent organic radical having 1 to about 12 carbon atoms, each subscript n is an integer from 1 to about 10, and y is an integer from 1 to about 10.

16. Q is -(R*) ｎ -S-R, and each R* is a divalent -(CH ２ 16. The sulfenylated silicon-containing compound of claim 15, wherein each R is H or a monovalent alkyl group having 1 to about 4 carbon atoms, and each n is an integer portion from about 2 to about 4.

17. A sulfonylated silicon-containing compound of formula (VI): Q*-Si(R １ ) ２ -(R*) ｎ -S(=O) ２ -R (TI) Here, Q* is Q ２＊ Or Q ３＊ and Q ２＊ is the formula -(R*) ｎ -S(=O) ２ -R moiety; and Q ３＊ is represented by the formula -O-[Si(R １ ) ２ -O] ｙ -Si(R １ ) ２ -(R*) ｎ -S(=O) ２ -R moiety and R １ each of R* is a divalent organic radical having 1 to about 8 carbon atoms, each of R is H or a monovalent organic radical having 1 to about 12 carbon atoms, each subscript n is an integer from 1 to about 10; and y is an integer from 1 to about 10.

18. Q* is Q ２＊ When each R* is -(CH ２ 20. The sulfonylated silicon-containing compound of claim 17, wherein each R is a H or a monovalent alkyl group having from 1 to about 4 carbon atoms.

19. Q* is Q ３ When R １ Each of R* is an alkyl group having 1 to about 4 carbon atoms, and each of R* is --(CH ２ 20. The sulfonylated silicon-containing compound of claim 17, wherein R is a aryl group, R is a aryl group, and each R is H or a monovalent alkyl group having 1 to about 4 carbon atoms.

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