Unprecedented B-H activation through Pd-catalysed B-Cvinyl bond coupling on borane systems

Abstract

A Pd-induced cascade B-Cvinyl coupling that produces multiple B-Cvinyl bonds starting from a single B-I bond has been demonstrated. The process is most probably stimulated by the geometrical disposition of the B-H bonds confronting the B-Pd sites, along with the hydride character of the B-H units. Two and one B-Cvinyl couplings on the metallacarborane substrate have been generally obtained, but formation up to six B-C vinyl bonds has been observed. A theoretical reaction mechanism involving an unprecedented B-H activation is proposed to interpret the multisubstitution process. The applicability of Heck reaction on metallacarboranes induced cascade B-Cvinylcoupling that produces multiple B-Cvinyl bonds starting from a single B-I bond. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.