Unique Steric Effect of Geminal Bis(silane) To Control the High <i>Exo</i>-selectivity in Intermolecular Diels–Alder Reaction
作者:Zengjin Liu、Xinglong Lin、Na Yang、Zhishan Su、Changwei Hu、Peihong Xiao、Yanyang He、Zhenlei Song
DOI:10.1021/jacs.5b09689
日期:2016.2.17
endo-selectivity predominantly. The conformational analysis of dienes suggests that (R3Si)2CH group effectively shields both sides of the diene moiety, ensuring the desired exo-selectivity. Moreover, the geminal bis(silane) can be further functionalized to transform the resulting ortho-trans cycloadducts into useful synthons, which makes the approach hold great potential for organic synthesis.
孪晶双(硅烷)[(R3Si)2CH] 的独特空间效应允许孪晶双(甲硅烷基)二烯与 α,β-不饱和羰基化合物的外选择性分子间 Diels-Alder 反应。该方法显示出良好的通用性,以良好的收率形成邻反式环己烯,在某些不对称情况下具有高外选择性和高对映选择性。通过与 R3SiCH2 和 R3Si 基团相比,突出了 (R3Si)2CH 基团出色的外立体控制能力,主要导致内向选择性。二烯的构象分析表明,(R3Si)2CH 基团有效地屏蔽了二烯部分的两侧,确保了所需的外选择性。此外,孪生双(硅烷)可以进一步官能化以将所得的邻反式环加合物转化为有用的合成子,