Nickel-mediated coupling reactions of carboryne with alkenes: A synthetic route to alkenylcarboranes

Abstract

Happily coupled: A nickel-carboryne complex 1 reacts with substituted styrenes 2 to afford alkenylcarboranes in moderate to very good yields with excellent regio- and steroselectivity. Either the "Heck-type" (3) or the "ene-reaction-type" product (4) could be isolated (see scheme). A reaction mechanism that involves alkene insertion followed by successive β-H elimination and reductive elimination steps is proposed. (Chemical Equation Presented). © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.