Cobalt(II)-Catalyzed Activation of C(sp3)-H Bonds: Organic Oxidant Enabled Selective Functionalization

Herein we develop a new "cobalt(II)/organic oxidant" catalytic system for the selective activation of 1 degrees, 2 degrees, and 3 degrees C(sp(3))-H bonds to construct C-N and C-O bonds, respectively. The method highlights the use of an organic compound (TsNHOPiv or its analogues) as an emerging oxidant and thus provides a flexible strategy for the preparation of indoline and benzoxazine derivatives. Attractive advantages of this cobalt catalysis include simple operation, low cost, mild conditions, and broad substrate scope. Furthermore, a catalytically competent hydroxylamine-chelated organometallic Co(III)species was synthesized, thus providing deep insights into the catalytic mechanism.