Ir-Catalyzed Intramolecular Transannulation/C(sp(2))-H Amination of 1,2,3,4-Tetrazoles by Electrocyclization

An efficient strategy for the intramolecular denitrogenative transannulation/C(sp(2))-H amination of 1,2,3,4-tetrazoles bearing C8-substituted arenes, heteroarenes, and alkenes is described. The process involves the generation of the metal nitrene intermediate from tetrazole by the combination of [Cp*IrCl2](2) and AgSbF6. It has been shown that the reaction proceeds via an unprecedented electrocyclization process. The method has been successfully applied for the synthesis of a diverse array of alpha-carbolines and 7-azaindoles.