Visible-Light-Induced Catalyst-Free Three-Component Reaction of α-Hydroxy Ketones, Styrenes, and 4-Cyanopyridine.

A visible-light-induced, transition-metal- and photosensitizer-free three-component acylpyridylation of styrenes is presented. In this strategy, α-hydroxy ketones play a triple role: they act as visible-light-activated photosensitizers, acylation reagents, and reductants. This approach does not require transition-metals, external photosensitizers, or reductive reagent, demonstrating high efficiency, mild reaction conditions, and robust tolerance to various functional groups.