Synthesis of Vinyl Chlorides via Triphosgene–Pyridine Activation of Ketones

Herein, we describe a mild method to prepare aliphatic and aromatic vinyl chlorides from their corresponding ketones via triphosgene–pyridine activation in dichloromethane at reflux. The mechanism of this reaction is proposed to involve formation of a putative α-chloro pyridinium carbamate intermediate, which appeared to readily undergo E2 elimination in the presence of pyridine.