Direct Access to Trifluoromethyl-Substituted Carbamates from Carbon Dioxide via Copper-Catalyzed Cascade Cyclization of Enynes

A copper-catalyzed cascade cyclization of enynes with Togni's reagent, carbon dioxide, and amines has been successfully developed. The reaction provides a direct and efficient route to a range of trifluoromethyl-substituted carbamates, which are difficult to access using existing methods. Mild reaction conditions, good functional tolerance, and wide substrate scope are the feactures of the protocol.