Selective C-N Bond Cleavage of N-Acylisatins: Towards High Performance Acylation/Arylation/Transamination Reagents

New multipurpose arylation/acylation/transamination reagents, N-acylisatins, have been developed by selective 'inside-outside' C-N bond cleavage under different catalytic conditions. As activated amides, N-acylisatins undergo Rh-catalyzed C-H arylation and Pd-catalyzed acylation by cleavage outside the C-N bond, and the desired biaryls and diaryl ketones were obtained in good to excellent yields. Generally, the combination of N-acylisatins with amines leads to a ring-opening reaction and formation of transamination products in a predictable manner through inside C-N bond cleavage. Interestingly, treatment of N-acylisatins with amines lead to unexpected outer-ring transamination products when CsF is added, which shows that CsF can favor the outside C-N bond cleavage path. Notably, this work presents a new strategy for multiple chemical transformations of a single amide to achieve various products by selective C-N bond cleavage.