Rh(III)-Catalyzed Enaminone-Directed C-H Coupling with Diazodicarbonyls for Skeleton-Divergent Synthesis of Isocoumarins and Naphthalenes

Diversity-oriented synthesis is tremendously useful for expanding the explorable chemical space but restricted by the limited available toolbox of skeleton-diversification chemistry. We report herein Rh(III)-catalyzed coupling of enaminones and diazodicarbonyls for skeleton-divergent synthesis of isocoumarins and naphthalenes. The diazodicarbonyl ring size and pH dependence of the skeleton-forming process demonstrates the achievement of both substrate-and reagent-controlled skeletal diversity generation in a single type of system. An intriguing C-C bond cleavage reactivity is critical for enabling facile synthetic access to isocoumarins.

Automated summary

Diversity-oriented synthesis is a valuable method for expanding the chemical space, but its application is limited by the available toolbox for skeleton-diversification chemistry. In this study, we report the Rh(III)-catalyzed coupling of enaminones and diazodicarbonyls for the synthesis of isocoumarins and naphthalenes with divergent skeletons. The dependence of the skeleton-forming process on the ring size of diazodicarbonyls and pH demonstrates the achievement of both substrate-and reagent-controlled skeletal diversity generation in a single system. Moreover, the C-C bond cleavage reactivity is found to be critical for facile synthetic access to isocoumarins.