Transition metal-free oxidative ortho-acylation of phenols with N-heteroarylmethanes via double C-H activation

The direct oxidative acylation of phenols with N-heteroarylmethanes via sp(3)C-H and sp(2)C-H double activation was achieved under transition metal-free reaction conditions. This transformation proceeds in a facile I-2/DMSO/O-2 system regio-selectively to produce valuable (2-hydroxyphenyl)arylmethanones from easily available starting materials in moderate to good yields. A plausible mechanism was proposed.