Ligand-Free, Quinoline N-Assisted Copper-Catalyzed Nitrene Transfer Reaction To Synthesize 8-Quinolylsulfimides.

An efficient copper-catalyzed, quinolyl N-directed nitrene transfer reaction to 8-quinolylsulfides was described. A variety of 8-quinolylsulfimides with different functional groups were synthesized in moderate to high yields. The obtained 8-quinolylsulfimides were proved to be promising novel type of bidentate ligands in Pd(II)-catalyzed allylic alkylation.

RuHCl(CO)(PPh3)3-Catalyzed Direct Amidation of Arene C-H Bond with Azides.

We first report the direct ortho C-H amidation of arenes with azides by using a novel and inexpensive RuHCl(CO)(PPh3)3 catalyst. The reaction proceeds efficiently in high yield over a broad range of substrates without requirement of any additional silver salt or additive.

Copper-Catalyzed Regioselective C-H Sulfonylation of 8-Aminoquinolines.

Copper(I)-catalyzed 5-sulfonation of quinolines via bidentate-chelation assistance has been developed. The reaction is compatible with a wide range of quinoline substrates and arylsulfonyl chlorides. Experimental and theoretical (DFT) investigation implicated that a single-electron-transfer process is involved in this sulfonylation transformation.

Iridium(III)-Catalyzed Regioselective Intermolecular Unactivated Secondary Csp(3) -H Bond Amidation.

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.

Copper-promoted S-arylation reactions with triarylbismuths for the synthesis of diaryl sulfides.

A simple approach for copper-promoted S-arylation reactions utilizing triarylbismuths or triarylantimonys as arylating reagents has been described. These reactions can be performed under mild conditions and exhibit remarkable functional group tolerance and chemoselectivity. The corresponding 2-arylthiopyridine 1-oxide derivatives and arylthioanilines/phenols have been successfully synthesized, achieving good to excellent yields across over 49 examples.

Rh(III)-catalyzed chelation-assisted intermolecular carbenoid functionalization of α-imino Csp(3)-H bonds.

A Rh(iii)-catalyzed cross-coupling/cyclization cascade of α-imino Csp(3)-H bonds with donor/acceptor α-acyl diazocarbonyl compounds has been developed. This novel transformation involves ligand-directed Csp(3)-H bond functionalization with carbenoids under the pyridine-chelation assistance, and offered an efficient access to synthetically versatile polysubstituted N-(2-pyridyl)pyrroles with a broad range of functional group tolerance.

Transition-Metal-Free Tandem Chlorocyclization of Amines with Carboxylic Acids: Access to Chloroimidazo[1,2-α]pyridines.

An efficient one-pot and transition-metal-free chlorocyclization cascade of 2-aminopyridines with aliphatic carboxylic acids is reported. This transformation provides a novel approach to 2-chloro- or 3-chloro-substituted imidazo[1, 2-α]pyridines with a broad range of substrate scopes.