Copper-Catalyzed Synthesis of 3-Silyl-1-silacyclopent-2-enes via Regio- and anti-Selective Addition of Silylboronates to Silicon-Containing Internal Alkynes.

A copper-catalyzed disilylative cyclization of silicon-containing internal alkynes with silylboronates has been developed for the synthesis of 3-silyl-1-silacyclopent-2-enes. The reaction proceeded regio- and anti-selectively under simple and mild conditions by employing a combination of nucleophilic silicon donors and electrophilic silicon acceptors. The reaction could also be extended to the synthesis of a 1-germacyclopent-2-ene and a silicon-centered spirocyclic compound by using appropriate alkyne substrates.