Highly selective α-hydrogermylation of alkynes catalyzed by an in situ generated bulky NHC–cobalt complex.

A new catalytic system, based on an octacarbonyl dicobalt(0) complex and bulky ligand, providing a route to α-vinylgermanes is described. The proposed method can be effectively used for Markovnikov-selective hydrogermylation of a number of terminal and internal alkynes. It has been proved that analogous catalytic systems containing less sterically demanding ligands cannot serve as selective catalysts in this transformation. [ABSTRACT FROM AUTHOR]