Co(III)-catalyzed Reaction Between 3-Diazoindolin-2-imines and 1-Pyrimidinylindoles for the Synthesis of 2,3′-Biindoles

An efficient and facile synthesis of 2,3'-biindoles through Co(III)-catalyzed direct C-H coupling of N-pyrimidinylindoles with 3-diazoindolin-2-imines is reported. This method provided 2,3'-biindoles under mild reaction conditions and in moderate to excellent yields. The reaction tolerated a number of functional groups and could be scaled up with practical usage. (C) 2020 Elsevier Ltd. All rights reserved.