Cobalt-Catalyzed Annulation of Amides with Isocyanides via C(sp2)–H Activation

A cobalt-catalyzed [4 + 1] cycloaddition of easily accessible amides with isocyanides for the efficient synthesis of 3-iminoisoindolinone derivatives in high yield under mild conditions via intramolecular C(sp2)–H activation and isocyanide insertion is reported. The annulation was found to be applicable to a broad range of substrates, including arylamides, heteroarylamides, and acrylamide derivatives. Strongly coordinating N-heterocyclic directing groups such as pyridine, pyrimidine, and even pyrazole were fully tolerated in this cobalt-catalyzed C–H activation reaction.