Solvent-controlled stereoselectivity in the hydrosilylation of alk-1-ynes catalysed by rhodium complexes

Abstract

New methodology for complete control of stereoselectivity in the hydrosilylation of alk-1-ynes is described. Alk-1-ynes react with triethylsilane to produce both (E)- and (Z)-vinylsilane, depending upon the reaction conditions, with high selectivity (91–97%). A [{Rh(cod)Cl}₂]-catalysed reaction using ethanol as a solvent gave rise to Z-selective conditions whilst E-selective conditions were achieved in [{Rh(cod)Cl}₂]/PPh₃ or [RhCl(PPh₃)₃]-catalysed reactions using acetonitrile as a solvent. A cationic rhodium(I) phosphine complex generated in situ was found to be the active species in E-selective conditions.