Bi-Catalyzed Trifluoromethylation of C(sp2)-H Bonds under Light
Takuya Tsuruta1, Davide Spinnato1, Hye Won Moon1
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany.
Abstract:
We disclose a Bi-catalyzed C-H trifluoromethylation of (hetero)arenes using CF3SO2Cl under light irradiation. The catalytic method permits the direct functionalization of various heterocycles bearing distinct functional groups. The structural and computational studies suggest that the process occurs through an open-shell redox manifold at bismuth, comprising three unusual elementary steps for a main group element. The catalytic cycle starts with rapid oxidative addition of CF3SO2Cl to a low-valent Bi(I) catalyst, followed by a light-induced homolysis of Bi(III)-O bond to generate a trifluoromethyl radical upon extrusion of SO2, and is closed with a hydrogen-atom transfer to a Bi(II) radical intermediate.
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