Direct C-H carboxylation with carbon dioxide using 1,2,3-triazol-5-ylidene copper(I) complexes
1,2,3-Triazol-5-ylidene copper(I) complexes (tzNHC-Cu) efficiently catalyzed the direct C-H carboxylation of benzoxazole and benzothiazole derivatives with CO2 to give the corresponding esters in excellent yields after treatment with alkyl iodi