Highly regio- and stereoselective synthesis of indene and benzo[b]furan derivatives via a Pd-catalyzed carboannulation of propargyl carbonates with nucleophiles

A new and efficient synthesis of indene and benzo[b]furan derivatives has been achieved via Pd-catalyzed carboannulation of propargyl carbonates with nucleophiles in good to excellent yields with high regio- and stereoselectivity. A novel sequence of nucleophilic attack is observed, and a possible mechanism is proposed.