[1,3]-Metal Shifts in Rhenium Alkynyl Carbene Complexes

Abstract

The electron-withdrawing SO2CF3 substituent of Cp(CO)2ReC(Tol)(C⋮CC6H4-p-SO2CF3) (1d) greatly accelerates rearrangement via a [1,3]-rhenium shift. The [1,3]-rhenium shift is proposed to proceed via an 18-electron dehydrometallacyclobutadiene intermediate formed by alkyne coordination concerted with an η5−η3 Cp ring slip