One‐Pot Synthesis of Benzodiazepines through RuII‐Catalyzed Regioselective [5+2] Annulation of N‐Aryl Amidines with Alkynyl Cyclobutyl Acetates.

A highly efficient strategy to construct benzo[d][1,3]diazepines via selective C−H bond activation of N‐aryl amidines and coupling with alkynyl cyclobutyl acetates was achieved successfully by RuII‐catalyzed [5+2] cyclization. This protocol features excellent regioselectivity, wide substrate tolerance, mild reaction conditions, which might be potentially applied in the discovery of lead compounds for the developing new drugs. [ABSTRACT FROM AUTHOR]