Conversion of trifluoromethyls into esters along with polyether upcycling via cation-transfer-catalyzed C–O/C–F metathesis

Abstract

Ester and trifluoromethyl groups play crucial roles in chemistry and drug design. However, the implementation of interconversion from a trifluoromethyl into an ester under wide conditions is not an easy task, because the C–F bond of the trifluoromethyl group possesses high bond energy and is extremely difficult to break. Herein, we present for the first time a silylium-ion-initiated method for intermolecular C–F/C–O metathesis, enabling selective activation of inert C(sp³)–F and C(sp³)–O bonds. This approach facilitates the defluoroalkoxylation of trifluoromethyl-substituted substrates and polyfluoroalkanes when combined with ethers or polyethers, thus building a bridge to convert trifluoromethyl groups into ester/ketone groups, along with polyether upcycling. We provide crystallographic evidence that clearly confirms that this reaction involves the formation of silyloxonium ions and Meerwein-type salt intermediates, followed by cationic ligand transformations.