Fig. 1. Strategies for hydrogen-atom-transfer-mediated C–H oxidation.
(A) Radical rebound mechanism for enzymatic and biomimetic C–H hydroxylation and halogenation (X = halide). (B) Radical relay pathway for C–H oxidation involving formation of a free radical that is trapped by a reactive metal center. (C) Proposed mechanism for Cu-catalyzed enantioselective cyanation of benzylic C–H bonds via radical relay.
