Total Synthesis of (-)-Actinophyllic Acid Enabled by a Key Dual Ir/Amine-Catalyzed Allylation.

A synthetic strategy for the catalytic asymmetric total synthesis of (-)-actinophyllic acid is described. This highly efficient and enantioselective approach allows the rapid installation of the four contiguous chiral centers (C16, C15, C20, and C19) by way of a dual Ir/amine catalytic allylation of 2-indolyl vinyl carbinol 6 and an aldol reaction of resultant chiral aldehyde 4a with 2-pyrrolidinone 5. The key indol-3-ylmethanamine moiety and 1-azabicyclo[4.2.1]nonane ring system were readily generated through a selective Mannich-like cyclization and an intramolecular N-alkylation, respectively.