Studies Of Rhodium-catalyzed Cyclization Reactions Derived From N-sulfonyl-1,2,3-Triazoles

Rh(II)-catalyzed denitrogenative transannulation of N-sulfonyl-1,2,3-triazoles has evolved as a useful synthetic strategy for constructing a wide variety of important heterocycles.Among them,oxonium ylide intermediate that formed by attacking of metal carbenes by hetero atoms is potentially useful in the organic synthesis.In this dissertation,a novel method for the preparation of spirocyclic indole ketone containing a quarter carbon center by intramolecular tandem cyclization of aryl-promoted oxonium ylide has been studied.It primarily includes three chapters:In the first part,we have briefly presented the structure and property of N-sulfonyl triazoles and the application of rhodium-catalyzed oxonium ylide intermediate involved reactions derived from N-sulfonyl triazoles in organic synthesis.In the second part,a novel Rh(II)/cobaloxime(III)dual catalysis strategy has been developed for the stereoselective synthesis of indolyl spiroindanones from readily accessible N-sulfonyl-1,2,3-triazoles.This binary-catalyst system enables an aza-vinyl carbene initiated Pictet-Spengler-type cyclization and sequential cobaloxime promoted intramolecular Mannich type reaction cascade.In addition,the substituent effect of indole ring and the electronic effect of the aromatic ring were discussed.In the third part: The rhodium-catalyzed preparation of oxazobenzene sulfonamide from lactam triazole has briefly discuessed.