Advancing C–H functionalization

Organic Synthesis The ability to selectively functionalize C–H bonds of complex molecules is one of the longstanding challenges for the organic synthesis community. Huang et al. demonstrate a practically useful method for highly regioselective C–H functionalization of ethers by using trisaminocyclopropenium as the electrophotocatalyst in the presence of a mild electrochemical potential and visible-light irradiation. The method was successfully applied to couple ethers with alkenes, alkynes, isoquinolines, and other azoles with no need of an external oxidizing agent. The electrophotocatalytic cycle involves hydrogen atom transfer from the substrate to the photoexcited catalyst radical dication. High regioselectivities for the less-hindered a position are achieved thanks to the steric effects of the catalyst structure. J. Am. Chem. Soc. 142 , 1698 (2020).