Total Synthesis of Indolizidine Alkaloids via Nickel-Catalyzed (4 + 2) Cyclization

• DOI: 10.1021/acs.orglett.9b04479
• Publication Date: 2020-01-13T20:12:15Z
• Authors: Jonas Renner; Ashish Thakur; Philipp M. Rutz; Jacob M. Cowley; Judah L. Evangelista; Puneet Kumar; Matthew B. Prater; Ryan M. Stolley; Janis Louie
• Keywords: Indolizidine

A Ni-catalyzed (4 + 2) cycloaddition of alkynes and azetidinones toward piperidinones was used as key reaction in the enantioselective synthesis naturally occurring indolizidine alkaloids. The benefits from use an easily accessible azetidinone advanced divergent intermediate to build core. This methodology has been applied total syntheses (+)-septicine, (+)-ipalbidine, (+)-seco-antofine illustrate applicability general approach.