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Catalytic carbon-carbon bond formation building on reductive coupling is a powerful method for the preparation of organic compounds. The identification of environmentally benign reductants is key for establishing an efficient reductive coupling reaction. Herein an efficient strategy enabling H2 as the sole reductant for the palladium-catalyzed allyl-allyl reductive coupling reaction is described. A wide range of allylamines and allylic alcohols as well as allylic ethers proceed smoothly to deliver the C-C coupling products under 1 atm of H2. Kinetic studies suggested that the dinuclear palladium species was involved in the catalytic cycle.

An efficient palladium-catalyzed hydrocarbonylative C–N coupling of alkenes with amides has been developed. The reaction was performed via hydrocarbonylation of alkenes, followed by acyl metathesis with amides. Both intermolecular and intramolecular reactions proceed smoothly to give either branched or linear amides in high turnover number (3500) with NH4Cl or NMP·HCl as a proton source under the palladium catalysis. This reaction offers a catalytic convenient approach to deuterated amides when inexpensive NMP·DCl served as a deuterium source.

A rhodium-catalyzed sequential oxidative C-H annulation reaction between ketazines and internal alkynes has been developed via C-H and N-N bond activation with air as an external oxidant, which led to an efficient approach toward isoquinolines with high atom efficiency at rt. Utilizing the distinctive reactivity of this catalysis, both N-atoms of the azines could be efficiently incorporated to the desired isoquinolines under very robust and mild reaction conditions.

A simple copper-mediated cyanation of aryl halide with the combination of ammonium bicarbonate and N,N-dimethylformamide as a cyanide source is achieved, providing nitriles in moderate to good yields. This new approach represents an exceedingly practical and safe method for the synthesis of aryl nitriles.