Total syntheses of the parvistemoline alkaloids enabled by stereocontrolled Ir/Pd-catalyzed allylic alkylation.

ABSTRACT: The functionalized polycycle with densely contiguous tertiary stereocenters is a formidable challenge in synthesizing the parvistemoline family of Stemona alkaloids. We herein report their catalytic, asymmetric total syntheses in 13-14 steps from commercially available 2-(methoxycarbonyl)-pyrrole, featuring the development and deployment of an Ir/Pd-synergistically-catalyzed allylation of α-non-substituted keto esters with secondary aryl-substituted alcohols, stereodivergently accessible to four stereoisomers. Using chiral Pd-enolate and Ir π-allyl complex under neutral conditions, no epimerization occurs. Additionally, the other two adjacent stereogenic centers can be installed diastereoselectively by Zn(BH₄)₂-promoted reduction and Krische's Ir-catalyzed 2-(alkoxyca

SUBMITTER: Liang X 

PROVIDER: S-EPMC11685622 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature