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.