Asymmetric Formal Synthesis of (−)-Cephalotaxine via Palladium-Catalyzed Enantioselective Tsuji Allylation

• DOI: 10.1021/acs.orglett.7b04008
• Publication Date: 2018-02-05T16:17:00Z
• Authors: Zhi-Wei Zhang; Cui-Cui Wang; Hong Xue; Yu Dong; Jian-Hua Yang; Shouxin Liu; Wen-Qing Liu; Wei-Dong Z. Li
• Keywords: 01 natural sciences; 0104 chemical sciences

Asymmetric synthesis of the pentacyclic alkaloid (-)-cephalotaxine was accomplished via palladium-catalyzed enantioselective Tsuji allylation for construction of the aza-containing tetrasubstituted stereogenic center (95% yield, 93% ee). The allyl enol carbonate precursor was prepared from Hanaoka's ketone intermediate, which was formed by a novel formic acid promoted ring-expansion reaction.