Rh(III)-Catalyzed annulative aldehydic C-H functionalization for accessing ring-fluorinated benzo[b]azepin-5-ones

Abstract

A new Rh(III)-catalyzed aldehydic C-H activation/[4 + 3] annulation cascade of N-sulfonyl-2-aminobenzaldehydes with gem-difluorocyclopropenes is reported for the first time, and used to produce a range of hitherto unreported precedented β-monofluorinated benzo[b]azepin-5-ones with good yields and complete regioselectivity. This approach features a broad substrate scope, good functional group tolerance, and high regioselectivity, which may include Rh(III)-catalyzed aldehydic C−H activation, tandem site-/regioselective insertion, defluorinated ring-scission, and 1,2-elimination.