Trimethylsilylacetylene is used in
Sonogashira couplings as the equivalent of
acetylene. Using this protected alkyne, as opposed to acetylene itself, prevents further coupling reactions. The
trimethylsilyl group can then be cleaved off with
TBAF or
DBU to form
phenylacetylene derivatives. Trimethylsilylacetylene is also used to synthesize
diphenylacetylene derivatives in a
one-pot Sonogashira coupling, in which the phenylacetylene derivative reacts with a second
aryl halide after in-situ deprotection. A less expensive alternative reagent is
2-methylbut-3-yn-2-ol, which after alkynylation is deprotected with base. Trimethylsilylacetylene is commercially available. It may also be prepared in a manner similar to other silyl compounds:
deprotonation of acetylene with a
Grignard reagent, followed by reaction with
trimethylsilyl chloride. Trimethylsilylacetylene is a precursor to 1,4-bis(trimethylsilyl)buta-1,3-diyne, a protected form of
1,3-butadiyne. ==History==