The total synthesis of (−)-strempeliopine via palladium-catalyzed decarboxylative asymmetric allylic alkylation

Abstract

In the work reported herein, the concise and enantioselective total synthesis of the Schizozygine alkaloid (−)-strempeliopine was developed. This synthetic strategy featured the palladium-catalyzed decarboxylative asymmetric allylic alkylation of N-benzoyl lactam to set up the absolute configuration at the C20 position, a highly diastereoselective one-pot Bischler–Napieralski/lactamization and iminium reduction sequence for the construction of the pentacyclic core structure, and the late-stage dearomative addition of indole, leading to the otherwise difficult-to-achieve hexacyclic indoline framework with complete control of four neighbouring stereocenters.