Palladium-Catalyzed Iodine Assisted Carbonylation of Indoles with ClCF 2 CO 2 Na and Alcohols.

A palladium-catalyzed iodine-assisted carbonylation reaction of indoles with readily available ClCF ₂ CO ₂ Na and alcohols has been developed. This protocol provides a practical and efficient approach to highly regioselective indole-3-carboxylates via a preiodination strategy of indoles. Different from classic carbonylation using toxic and difficult-to-handle carbon monoxide, this operationally simple and scalable reaction employed difluorocarbene as the carbonyl surrogate.