Salt-Free Preparation of Trimethylsilyl Ethers by B(C6F5)3-Catalyzed Transfer Silylation by Using a Me3SiH Surrogate

An unprecedented transfer silylation of alcohols catalyzed by the strong Lewis acid B(C6F5)(3) is described. Gaseous Me3SiH is released in situ by B(C6F5)(3)-catalyzed decomposition of 3-trimethylsilylcyclohexa-1,4-diene and subsequently reacts with an alcohol in a dehydrogenative Si-O coupling promoted by the same boron catalyst. Benzene and dihydrogen are formed during the reaction, but no salt waste is. This expedient protocol is applicable to several silicon groups, and the preparation of trimethylsilyl ethers presented here is potentially useful for alcohol derivatization prior to GLC analysis.