Copper-Catalyzed Cross-Coupling of Vinylsiloxanes with Bromoalkynes: Synthesis of Enynes

Enynes are versatile building blocks in organic synthesis. A copper-catalyzed Hiyama-type cross-coupling of vinylsiloxanes with bromoalkynes is presented. This mild and efficient method led to the formation of various sensitive enynes. The use of cis, trans, and 1,1'-disubstituted vinylsiloxanes was allowed, and full retention of stereochemistry was observed. Sensitive groups such as halides, unsaturated ketones, and aldehydes were fully tolerated.