Chao Pi

Sulfonylation of Quinoline N-Oxides with Aryl Sulfonyl Chlorides via Copper-Catalyzed C–H Bonds Activation

An efficient and concise one-pot protocol to synthesize sulfonylated quinoline N-oxides via copper-catalyzed C-H bond activation has been developed. Commercially available and less expensive aryl sulfonyl chlorides were used as the sulfonylation reagents. Various 2-aryl sulfonyl quinolines were obtained in up to 91% yields in chemo- and regioselective manners.

Palladium(II)-Catalyzed Direct Regioselectively Oxidative Acylation of Azobenzenes with Toluene Derivatives

A highly efficient and practical procedure to acylazobenzene via Pd-catalyzed oxidative C-H bond activation from toluene has been developed. Various mono- and diacylazobenzene were afforded simultaneously in moderate to excellent yields for 33 examples. Toluene and its derivatives were served as potential and ideal acylation reagents. The mono- and diacylated products could be controlled by the oxidant loading.

Synthesis of Ferrocene Derivatives with Planar Chirality via Palladium-Catalyzed Enantioselective C-H Bond Activation

The first catalytic and enantioselective C-H direct acylation of ferrocene derivatives has been developed. A series of 2-acyl-1-dimethylaminomethylferrocenes with planar chirality were provided under highly efficient and concise one-pot conditions with up to 85% yield and 98% ee. The products obtained could be easily converted to various chiral ligands via diverse transformations.

Iridium-Catalyzed Direct C–H Sulfamidation of Aryl Nitrones with Sulfonyl Azides at Room Temperature

Ir(III)-catalyzed direct C-H sulfamidation of aryl nitrones has been developed to synthesize various sulfamidated nitrones in moderate to excellent yields with excellent regioselectivity and broad functional group tolerance. This transformation could proceed smoothly at room temperature with low catalyst loading in the absence of external oxidants, acids, or bases. Molecular nitrogen was released as the sole byproduct, thus providing an environmentally benign sulfamidation process. And this protocol could efficiently apply to synthesize the substituted benzisoxazoline via one-step transformation from the product.

Iodine-Catalyzed Direct C–H Alkenylation of Azaheterocycle N-Oxides with Alkenes

An efficient and regioselective alkenylation of azaheterocycle N-oxides with alkenes catalyzed by iodine under metal- and external oxidant-free reaction conditions has been developed. A variety of (E)-2-styrylazaheterocycles have been produced in moderate to excellent yields. The mechanistic exploration indicated that the N-oxide group played dual roles as both the directing group and an internal oxidant in this catalytic cycle.