Metal-Free Generation of Acyl Radical via Photoinduced Single- Electron Transfer from Lewis Base to Acyl Chloride

We herein describe a simple approach for generating acyl radical from acyl chloride via photoinduced single-electron transfer. It has been demonstrated that the generated acyl radicals could react with various substrates, including isocyanides, meth-acrylamides, alkenes, alkynes, and enynes, to afford diverse heterocycles (>10 classes). Mechanistic analyses show that a photoactive charge transfer complex between acyl chloride and a Lewis base additive is involved in enabling the photogeneration of the acyl radical. The study exemplifies a new and simple method of photoactivation of carbonyl compounds.