Photochemical Thio- and Selenoesterification of Aldehydes via C–H Bromination

Thio- and selenoesters moieties are found in a wide variety of pharmaceuticals and functional materials. While photochemical transformations have attracted considerable attention in recent years, the photochemical thioesterification of aldehydes has been employed primarily in photocatalytic processes, and the photochemical selenoesterification of aldehydes has not yet been reported. Here, we report the photochemical thio- and selenoesterification of aldehydes via C–H bromination. A variety of thio- and selenoesters were synthesized from aldehydes with thiols and selenophenol via acyl-bromide intermediates under purple-LED irradiation. As multisubstituted thio- and selenoesters are typically prepared from carboxylic acids or acyl chlorides using activating agents, the present mild method starting from aldehydes with thiols or selenol offers a valuable alternative to pharmaceuticals and functional materials.