The palladium-catalyzed Suzuki−Miyaura cross-coupling of N-acyl-5,5-dimethylhydantoins with arylboronic acids has been developed via selective amides C−N bond cleavage. The new reagent is commercially available and air-/ moisture-stable, and it offers a variety of ketones in good yields through Suzuki coupling under mild conditions (up to 95%).

A highly efficient one-pot transamidation of primary amides has been developed under transition-metal free conditions, generating a variety of amides including hindered amides in good yield (up to 86%) catalyzed by CsF.

We report herein a two-step one-pot strategy for the synthesis of benzoxazoles from amides by using cesium fluoride/copper as catalysts. This approach involves the in situ generation of acyl fluorides from the corresponding amides, and the acyl fluorides undergo transamidation and cyclization to give benzoxazoles in good yields. In this work, the amide CÀ N bonds are activated by CsF to form the acyl fluoride intermediates, which further react with o-bromoanilines to efficiently yield benzoxazoles. Notably, this methodology demonstrates a broad substrate scope, as primary/secondary benzamides are well tolerated, and this process might facilitate the development of one-pot transformations of amides. Scheme 5. Control experiments. Scheme 6. Preliminary mechanism studies. Scheme 7. Scale-up of the one-pot reaction.

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.magnified image