The direct cross-coupling of quinoline-N-oxides with olefin derivatives has been realized using palladium acetate as the catalyst in the absence of external ligand and oxidant to give the corresponding 2-alkenylated quinolines and 1-alkenylated isoquinolines chemo- and regioselectively in 27−95% yield. The catalytic process is proposed to proceed via direct C−H bond activation of the quinoline-N-oxide with Pd(OAc)2 followed by Heck coupling with the olefin. The resultant N-oxide of the alkenylated quinoline can oxidize the reduced Pd(0) to regenerate the Pd(II) active species and simultaneously release the 2-alkenylated quinoline without using any external oxidants and reductants.

A novel strategy of dehydrogenative Heck reaction controlled by redox process of ferrocene has been developed. Commercially available chiral amino acid as ligand realized asymmetric dehydrogenative Heck reaction, leading to planar-chiral ferrocene derivatives with excellent enantioselectivity and in good to excellent yields (up to 99% ee and 98% yield).Scheme 1 Palladium-catalyzed direct alkenylation of N,N-dimethylaminomethylferrocene.

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.

An efficient and regioselective synthesis of fused polycyclic furo[3,4-c]indolo[2,1-a]isoquinolines through Rh(III)catalyzed cascade C−H activation/annulation/lactonization of 2-arylindoles and 4-hydroxy-2-alkynoates has been developed. This cascade reaction displays high step economy and efficiency and tolerates various functional groups. The titled polycyclic furo[3,4c]indolo[2,1-a]isoquinolines exhibit fluorescence emission.

A direct C-H bond phosphonation of quinoxalin-2(1H)-ones with H-phosphonates, H-phosphinates or H-phosphine oxides has been developed. A wide variety of heteroaryl phosphonates were obtained in up to 92% yield for 20 examples under transition-metal-free conditions. This protocol tolerates a broad scope of substrates and features practicality, high efficiency, environmental friendliness and atom economy.

An efficient and concise one-pot strategy for the direct alkylation of quinoline N-oxides via palladium-catalyzed dual C À H bonds activation has been developed. This methodology provides quinoline-containing heterocyclic molecules in moderate to excellent yields.

A highly efficient and concise one-pot strategy for the direct amination of quinoline N-oxides via copper-catalyzed dehydrogenative C-N coupling has been developed. The desired products were obtained in good to excellent yields for 22 examples starting from the parent aliphatic amines. This methodology provides a practical pathway to 2-aminoquinolines and features a simple system, high efficiency, environmental friendliness, low reaction temperature, and ligand, additives, base, and external oxidant free conditions.

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.