Visible-Light-Initiated Manganese-Catalyzed E-Selective Hydrosilylation and Hydrogermylation of Alkynes.

Manganese-photocatalyzed activation of the Si-H bond in silanes for the hydrosilylation of alkynes has been developed. The mild protocol operates efficiently with high regioselectivity ( anti-Markovnikov) and stereoselectivity ( Z/ E ratio ranges from 92:8 to >99:1), providing a wide range of Z-vinylsilanes in high yields. Moreover, visible-light-induced manganese-catalyzed activation of the Ge-H bond for E-selective alkyne hydrogermylation is reported for the first time.