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We disclose a Ni-catalyzed reductive arylcyanation of alkene using environmentally benign and nontoxic organo cyanating reagent N-cyano-N-phenyl-p-toluenesulfonamide. This reaction provides a new method for the rapid synthesis of cyanosubstituted oxindoles and isoquinoline-1,3-diones and features high functional group tolerance. In addition, an enantioselective version was developed for the construction of enantiomerically enriched 3-cyanomethyl oxindole. This method has also been applied to the synthesis of natural alkaloids (+)-esermethole and (+)-physostigmine.

The reactivity of metal-hydride complexes can be harnessed by the modification of ancillary ligands. With the aim of improving the hydride-donor ability of the key MnÀ H intermediate and reducing steric hindrance, we herein report the rational design of a versatile and efficient NHC-based NNC-pincer Mn catalyst for hydrogenation reactions. This newly developed catalyst exhibited higher activity than the corresponding NNP-pincer Mn catalyst owing to its reduced steric hindrance and enhanced MnÀ H σ-bonding orbital energy level through a π-antibonding interaction. Using this highly active NNC-pincer Mn catalyst, a rich array of polar unsaturated compounds (> 80 examples) including esters, N-heteroarenes, amides, carbonates, and urea derivatives, were successfully hydrogenated under relatively mild conditions. This work represents a rare example of a general phosphine-free Mn-catalyzed hydrogenation system.

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