通过一锅S N 2'烯丙基化-Wittig策略从磷鎓叶立德,烯丙基碳酸酯和醛中无催化剂地合成烷基二烯
摘要:
提出了通过区域选择性的S N 2'方法将稳定的磷化磷与烯丙基碳酸酯进行无催化剂的烯丙基烷基化反应。随后的与脂肪族和芳香族醛以及乙烯酮的一锅Wittig反应可提供结构多样的跳跃式二烯(1,4-二烯),且产率高,并且具有灵活的取代基图案,具有中等至出色的立体选择性。这种单锅S N 2'烯丙基化-维蒂希(Wittig)策略构成了一种方便有效的合成方法,用于从容易获得的起始原料中高度官能化的二烯。
通过一锅S N 2'烯丙基化-Wittig策略从磷鎓叶立德,烯丙基碳酸酯和醛中无催化剂地合成烷基二烯
摘要:
提出了通过区域选择性的S N 2'方法将稳定的磷化磷与烯丙基碳酸酯进行无催化剂的烯丙基烷基化反应。随后的与脂肪族和芳香族醛以及乙烯酮的一锅Wittig反应可提供结构多样的跳跃式二烯(1,4-二烯),且产率高,并且具有灵活的取代基图案,具有中等至出色的立体选择性。这种单锅S N 2'烯丙基化-维蒂希(Wittig)策略构成了一种方便有效的合成方法,用于从容易获得的起始原料中高度官能化的二烯。
We report herein a nickel-catalyzed ring-opening allylation of cyclopropanols with allylic carbonates that occurs under mild and neutral conditions. The reaction displays linear selectivity for both linear and branched acyclic allylic carbonates and is also applicable to cyclic allylic carbonates, affording a variety of δ,ε-unsaturated ketones in moderate to good yields. Mechanistic experiments are
Asymmetric Construction of Functionalized Bicyclic Imides via [3 + 2] Annulation of MBH Carbonates Catalyzed by Dipeptide-Based Phosphines
作者:Fangrui Zhong、Guo-Ying Chen、Xiaoyu Han、Weijun Yao、Yixin Lu
DOI:10.1021/ol301647g
日期:2012.7.20
A highly enantioselective [3 + 2] annulation of MBH carbonates and maleimides catalyzed by chiral phosphines has been developed. In the presence of 5 mol % of L-Thr-L-Val-derived phosphine 6, functionalized bicyclic imides were prepared in excellent yields, and with high diastereoselectivities and nearly perfect enantioselectivities.