Radical Germylzincation of Aryl- and Alkyl-Substituted Internal Alkynes

Org Lett. 2021 Jun 4;23(11):4426-4430. doi: 10.1021/acs.orglett.1c01367. Epub 2021 May 25.

Abstract

The stereoselective germylzincation of internal alkynes delivering trisubstituted vinylgermanes is achieved via a radical chain process involving Ph3GeH and Et2Zn with AIBN as the initiator. Excellent levels of regiocontrol are observed for nonsymmetric (aryl, alkyl)-substituted alkynes and for propargylic alcohols with aryl-, alkyl-, or silyl-substituted alkynes. The germylzincation reaction can be combined in one pot with the Cu(I)-mediated electrophilic substitution of the C(sp2)-Zn bond to obtain synthetically challenging tetrasubstituted vinylgermanes.