Chloromethyl trimethylsilane

Among the Friedel-Crafts alkylations of aromatic compounds with (chlorinated alkyl)silanes, the alkylation of benzene with (tt>-chloroalkyl)silanes in the presence of aluminum chloride catalyst was generally affected by two factors the spacer length between the Cl and silicon and the electronic nature of substituents on the silicon atom of (w-chloroalkyl)silanes. As the spacer length between the C—Cl and silicon increases from (chloromethyl)silane to (/i-chloroethyl)silane to (/-chloropropyl)silane, the reactivity of the silanes increases. As the number of chloro-groups on the silicon decreases from (chloromethyl)trichlorosilanes to (chloromethyl)methyldichlorosilanes to (chloromethyl)trimethylsilanes, the... 

Alkenylsilanes can be prepared from aldehydes and ketones using lithio(chloromethyl)trimethylsilane. The adducts are subjected to a reductive elimination by lithium naphthalenide. This procedure is stereoselective for the E-isomer with both alkyl and aryl aldehydes.82... 

Analogous reactions were also used for the preparation of silyl derivatives, through reaction with (chloromethyl)trimethylsilane ... 

Methoxymethyl trimethylsilane (trimethylsilylmethyl methyl ether) [14704-14-4] 118.3, b 83°/740mm, d 5 0.758, n2D5 1.3878. Forms an azeotrope with MeOH (b 60°). If it contains MeOH (check IR for bands above 3000cm1) then wash with H2O and fractionate. A possible impurity could be chloromethyl trimethylsilane (b 97°/740mm). [JACS 70 4142 1948]. 

Peterson reaction (5, 724 9, 493). This reaction is limited by the fact that chloromethyl-trimethylsilane is the only commercially available suitable silane. Ager2 has now found two general routes to a a-trimethylsilylcarbanions 3, which undergo the Peterson reaction to give alkenes (4) in satisfactory yield. 

Primary amines.9,22,62 Direct amination of chloromethyl-trimethylsilane illustrates the diliiculty of stopping the reaction at the monoalkylation level with the formation of up to 30% of the bis(trimethylsilylmethyl) amine even when a large excess of ammonia is employed. The same process has been used to prepare aminomethylsiloxanes where the formation of a small amount of the secondary amine is also observed.63 See also Ref. 24. 

Table 1. Cyclopropanation of Alkenes with Trimethylsilylcarbene Generated from (Chloromethyl)trimethylsilane...

The products obtained from the reaction of (chloromethyl)trimethylsilane with organolithium reagents depend very much on the structure of the lithium compound. While lithium 2,2,6,6-tetramethylpiperidide initiates an a-elimination as described above, the treatment with sec-butyllithium leads to the formation of chloro(trimethylsilyl)methyllithium (11). This reagent cyclopropanates an electron-deficient alkene through sequential Michael addition and intramolecular ring closure (MIRC reaction), for example, the formation of cyclopropane 12. 

Several different methods have been employed for the preparation of diazo(trimethylsilyl)meth-ane (1). At present, the best synthetic method seems to be the diazo transfer reaction between diphenylphosphoryl azide and (trimethylsilyl)methylmagnesium chloride.However, the product often contains (chloromethyl)trimethylsilane and hexamethyldisiloxane as impurities. This method can also be employed for the synthesis of diazo(triethylsilyl)methane and diazo(di-ethylmethylsilyl)methane. The diazo transfer reaction can also be carried out with (trimethyl-silyl)methyllithium and tosyl azide. Other methods are the silylation of diazomethane with (trimethylsilyl)trifluoromethanesulfonate or chloro(trimethyl)silane and the base-induced cleavage of A-nitroso-A-[(trimethylsilyl)methyl]urea or the related carbamate or acet-amide.2° =... 

Diethyl l-(ethoxycarbonyl)methylphosphonate can be selectively C-alkylated in comparable yield (65%) using the less expensive (chloromethyl)trimethylsilane in heterogeneous conditions with dry KgCOg at 60"C in the presence of a small amount of Nal. The rzz7//rz-(trimethylsilyl)arylphosphonates... 

Chloromethyl)trimethylsilane, also available from Aldrich Chemical Company, Inc., was purchased from Wako Pure Chemical Industries, LTD. and used directly. 

In order to obtain [(trimethylsilyl)methyl]cyclopentadiene, a mixture of (chloromethyl)trimethylsilane (Aldrich) and sodium cyclopentadienide in anhydrous tetrahydrofuran (Aldrich) was stirred for two days at room temperature under a nitrogen atmosphere. The dark red Hquid obtained was filtered and distilled at room temperature (0.15 torr). The final product was employed during further kinetic studies. 

Preparative Methods Me3SiCH2S02Cl is (1) formed in 58% isolated yield via reaction of (chloromethyl)trimethylsilane with thiourea in ethanol followed by concentration and chlorination in water, extraction, and distillation . (2) formed in 63% isolated yield by peracetic acid oxidation of (trimethylsi-lyl)methanethiol followed by treatment with phosphorus(V) chloride (3) formed in 84% yield through reaction of Me3-SiCH2Cl with magnesium followed by sequential reaction of the Grignard reagent with sulfur dioxide followed by chlorine and (4) formed in 53% yield through reaction of tetramethylsilane with sulfuryl chloride. ... 

The benzylammonium salts 41 were prepared by reacting glycine methyl esters 40 with (chloromethyl)trimethylsilane followed by treatment with iodomethane. The reaction of 41 with cesium fluoride afforded a mixture of Stevens rearrangement products 47-49 formed from iV-ylides 42,... 

Similar to (chloromethyl)trimethylsilane, (chloromethyl)di-methylphenylsilane can be used to prepare alkenes via a Peterson olefination by treating C=0 compounds with Grignard 29. However, due to its propensity for rearrangements under the conditions needed for the elimination step, 1 appears less suited for this task than (chloromethyl)trimethylsilane if the silyl terminal alkenes are desired. However, in a parallel transformation, it was found that if the )3-silylalcohol 31 is treated with magnesium iodide etherate, then the Julia ring-opened homoallylation adduct 32 could be isolated (eq 15). ... 

There are currently no published reviews on the use of this reagent. For a review of (chloromethyl)trimethylsilane, see Anderson, R., Synthesis 1985, 717. 

Preparative Methods three methods of preparation have been reported (a) from the treatment of ethyl bromoacetate with zinc followed by the reaction with chlorotrimethylsUane and subsequent reduction of the resultant ethyl trimethylsUylacetate with lithium aluminum hydride or borane-tetrahydrofuran (eq 1) (b) from the hydroboration/oxidation or oxymercu-ration/ demercuration of vinyltrimethylsUane (eq 2) and (c) most conveniently, by the reaction of the Grignard reagent formed from (chloromethyl)trimethylsilane with paraformaldehyde (eq 3). ... 

Preparative Method obtained in high yield by reaction of sodium azide and (chloromethyl)trimethylsilane in DMF or HMPAi at 80 °C. 

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