Visible Light-Induced Reductive Alkynylation of Aldehydes by Umpolung Approach

Reductive alkynylation of aldehydes by the Umpolung approach was developed using a photoredox catalyst under blue LED irradiation. Ketyl radicals, generated by single-electron reduction of aldehydes through proton-coupled electron transfer (PCET), reacted with electrophilic alkynylsulfones. Sterically demanding bulky aldehydes reacted smoothly under the Umpolung reaction conditions. Moreover, the alkynylation proceeded chemoselectively with an aryl aldehyde group in the presence of other carbonyl groups including an aliphatic aldehyde group.

Automated summary

A reductive alkynylation of aldehydes using the Umpolung approach was developed with a photoredox catalyst under blue LED irradiation. Bulky aldehydes reacted smoothly under these conditions, and the alkynylation proceeded chemoselectively even in the presence of other carbonyl groups.