Triphenylgermane adds easily to acetylenes in the presence of Et3B to give (E)- or (Z)-alkenyltriphenylgermanes, respectively, under excellent control of regio- and stereoselectivities.
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