Selective radical defluorinative germylation and hydrogermylation of α-trifluoromethylalkenes

Abstract

α-Trifluoromethylalkenes are pivotal scaffolds in pharmaceutical, agrochemical, and material science. Recent advances have focused on their defluorinative functionalization or hydrofunctionalization with carbon-or silicon-containing coupling partners. However, as a fellow group 14 element, strategies for introducing germanium into α-trifluoromethylalkenes, most notably defluorinative germylation, remain largely underdeveloped. Herein, we describe a versatile method for the visible-light-mediated defluorinative germylation of α-trifluoromethylalkenes with germanes by the combination of organic photoredox and HAT catalysis. The organic base serves as the key factor in achieving selective conversion. When pyridine is replaced with DMAP, the reaction encounters a selectivity switch to hydrogermylation, affording the trifluoromethylalkylated germane derivatives.