Acyl Radicals from Terminal Alkynes: Photoredox-Catalyzed Acylation of Heteroarenes

A photoredox-mediated acylation reaction of electron deficient heteroarenes with terminal alkynes is reported. The method relies on oxidative cleavage of phenylacetylenes for generation of acyl radicals as a key enabling feature. The reaction is regioselective with broad substrate scope. Quantum yield investigations support a radical chain mechanism.