Regio- and steroselective cross-metathesis of silylacetylenes with terminal olefins and α,ω-dienes

Authors:

• Sylwia Ostrowska,
• Beata Powała,
• Magdalena Jankowska-Wajda,
• Patrycja Karolina Żak,
• Szymon Rogalski,
• Bożena Wyrzykiewicz,
• Cezary Pietraszuk

Abstract

Second generation Grubbs catalyst [RuCl₂(H₂IMes)(PCy₃)(CHPh)] initiates regio- and stereoselective cross-metathesis of silylacetylenes with 1-alkenes and α,ω-dienes leading to the formation of E-2-silyl-1,3-dienes and E-2-silyl-1,3,n-trienes, respectively. Efficient progress of the reaction is achieved by using 5-8 mol% of the benzylidene initiator and twofold excess of olefin (with respect to silylacetylene) as well as ethereal solution of HCl (10-20 mol% with respect to the catalyst) as an activator. The reaction is proposed to be catalysed by alkylidene complex [RuCl₂(H₂IMes)(PCy₃)(CHR)] (where R = alkyl, n-alkenyl) generated from the benzylidene initiator, and proceed via initial interaction of a metal alkylidene with a triple bond.