Asymmetric total synthesis of (−)-javaberine A and (−)-epi-javaberine A based on catalytic intramolecular hydroamination of N-methyl-2-(2-styrylaryl)ethylamine
作者:Saho Uenishi、Rina Kakigi、Kumiko Hideshima、Akari Miyawaki、Junpei Matsuoka、Tokutaro Ogata、Kiyoshi Tomioka、Yasutomo Yamamoto
DOI:10.1016/j.tet.2021.132165
日期:2021.6
Asymmetric total synthesis of (–)-javaberine A and its epimer was achieved by utilizing two methods for isoquinoline synthesis, asymmetric hydroamination of N-methyl-2-(2-styrylaryl)ethylamine and Bischler-Napieralski cyclization. Intramolecular asymmetric hydroamination of N-methyl aminoalkene 4 was catalyzed by lithium amide–chiral bisoxazoline to give tetrahydroisoquinoline (S)-laudanosine with
(-)-javaberine A及其差向异构体的不对称总合成是利用两种异喹啉合成方法:N-甲基-2-(2-苯乙烯基芳基)乙胺的不对称加氢胺化和Bischler-Napieralski环化而实现的。酰胺锂-手性双恶唑啉催化N-甲基氨基烯烃4的分子内不对称氢化胺化反应,得到对映体选择性好,产率高的四氢异喹啉(S)-月桂肌苷。(S)-月桂肌苷的N-脱甲基通过Polonovski-型反应完成,得到(S)-去甲月桂肌苷。(S的凝结)-去甲月桂花碱和高鸟氨酸,随后进行Bischler-Napieralski环化,LiAlH 4还原和O-去甲基化,提供了(8 R,14 S)-(-)-javaberine A,对应于天然javaberine A的对映体。(8 S,还成功地合成了14 S)-(–)-Javaberine A,它对应于天然Javaberine A的C14-顶基。