通过 Ph3SnH/Et3B 引导的 O-指向的双自由基炔烃氢锡化、双 I-Sn 交换和双 Stille 偶联反应，合成 (+)-阿曲汀的 C(7)-C(22) 片段。

Synthesis of the C(7)-C(22) sector of (+)-acutiphycin via O-directed double free radical alkyne hydrostannation with Ph3SnH/Et3B, double I-Sn exchange, and double Stille coupling.

机构信息

The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen's University Belfast , Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom.

出版信息

Org Lett. 2014 Feb 21;16(4):1168-71. doi: 10.1021/ol500050p. Epub 2014 Feb 6.

DOI:10.1021/ol500050p

PMID:24502452

Abstract

Herein a new double O-directed free radical hydrostannation reaction is reported on the structurally complex dialkyldiyne 11. Through our use of a conformation-restraining acetal to help prevent stereocenter-compromising 1,5-H-atom abstraction reactions by vinyl radical intermediates, the two vinylstannanes of 10 were concurrently constructed with high stereocontrol using Ph3SnH/Et3B/O2. Distannane 10 was thereafter elaborated into the bis-vinyl iodide 9 via O-silylation and double I-Sn exchange; double Stille coupling of 9, O-desilylation, and oxidation thereafter furnished 8.

摘要

本文报道了一种新的双 O 导向自由基氢锡化反应，该反应针对结构复杂的二烷基二炔 11。通过使用构象限制缩醛来帮助防止乙烯基自由基中间体进行影响立体中心的 1,5-H-原子消除反应，我们使用 Ph3SnH/Et3B/O2 以高立体选择性同时构建了 10 的两个乙烯基锡烷。随后，二锡烷 10 通过 O-硅烷化和双 I-Sn 交换转化为双乙烯基碘化物 9；9 的双 Stille 偶联、O-去硅烷基化和氧化反应后得到 8。