High-valent Cu(III)-CF 3 compound-mediated esterification reaction.

Cu(III)-CF 3 compounds are reported herein as novel coupling reagents to mediate ester synthesis from carboxyl acids and alcohols/phenols. Carboxylic acids are transformed to trifluoromethyl ester and acyl fluoride activated species that interact with each other. The broad substrate scope and late-stage application of this method are demonstrated. This study opens up new opportunities to develop interesting reactions using Cu(III)-CF 3 compounds without transferring a CF 3 group to the products.