For the first time, a highly regioselective intermolecular sulfonylamidation unactivated secondary Csp(3) -H bond has been achieved using Ir(III) catalysts. The introduced N,N'-bichelating ligand plays a crucial role in enabling iridium-nitrene insertion into a secondary Csp(3) -H bond via an outer-sphere pathway. Mechanistic studies and density functional theory (DFT) calculations demonstrated that a two-electron concerted nitrene insertion was involved in this Csp(3) -H amidation process. This method tolerates a broad range of linear and branched-chain N-alkylamides, and provides efficient access to diverse γ-sulfonamido-substituted aliphatic amines.

A cobalt(II)-catalyzed regioselective aryl C−H bond oxygenation between arenes and aryl or aliphatic carboxylic acids under bidendate-chelation assistance is developed. This method provides an efficient approach to acyoxy-substituted arenes with a broad range of functional group tolerance. Furthermore, this reaction system could be further applied to the preparation of polyfunctional naphthylenes.

A Ru(II)-catalyzed approach for the rapid assembly of 1,2-benzothiazines has been developed to enable the coupling-cyclization of aryl Csp 2 ÀH bonds with a-carbonyl sulfoxonium ylides via Csp 2 ÀH activation process. The present method could be further applied to the construction of the 4-substituted 1,2benzothiazine skeletons.

A Rh(iii)-catalyzed regioselective intermolecular carbenoid insertion into the N-methylene Csp3–H bond has been achieved via an outer-sphere pathway.

A Co(II)-catalyzed pyridyl C−H bond carbenoid insertion with α-diazoacetates has been realized. This transformation features a highly regioselective C−C bond formation at the C3-position of pyridines, providing an efficient access to diverse α-aryl-α-pyridylacetates.