Highly Chemo- and Site-Selective Aromatic C-H Bond Functionalization of Phenols with α-Aryl-α-diazoketones via Gold Catalysis

Herein, we report the direct C(sp²)-H functionalization of unprotected phenols with α-aryl α-diazoketones using gold complexes derived from tris(2,4-di-tert-butylphenyl) phosphite. This protocol features readily available starting materials, exclusive C(sp²)-H functionalization, suppressed O-H insertion, and inhibited Wolff rearrangement, along with broad substrate scope, mild conditions, high conversion, and facile product derivatization. It provides a novel strategy for selective C(sp²)-H functionalization, expanding gold-catalyzed carbene chemistry utility.