Rhodium(III)-Catalyzed Intramolecular Annulation through C-H Activation: Total Synthesis of (±)-Antofine, (±)-Septicine, (±)-TyIophorine, and Rosettacin

摘要

The indolizidine structural motif forms the core of many natural products with pharmacological relevance, such as indolizidine and phenanthroindolizidine alkaloids (septi-cine (1), antofine (2), and tylophorine (3)), camptothecin (4, CPT), and aromathecin alkaloids (rosettacin (5) and 22-hydroxyacuminatine (6)). While a number of synthetic methods for the construction of these scaffolds have been reported,the development of conceptually different synthetic approaches is still of great interest.