Decarboxylative and Denitrative Trifluoromethylation for the Synthesis of CvinylCF₃ Compounds with Togni (II) Reagent

A highly efficient dimethylformamide (DMF)‐promoted decarboxylative trifluoromethylation of α,β‐unsaturated carboxylic acids with Togni (II) reagent under metal‐free conditions has been developed. The reactions showed good yields, high stereoselectivities and excellent functional group tolerance. Mechanistic studies confirmed that free‐radical processes were involved in this system since the CF 3 radical had been clearly trapped by scavengers. This method has been extended to the denitrative trifluoromethylation of β‐nitrostyrenes in the presence of an iron(III) catalyst. magnified image