已经开发了乙烯基环丙烷二羧酸酯和3-硝基吲哚之间的反式-非对映选择性的Pd催化的脱芳香性[3 + 2]环加成反应。该反应提供具有通用的乙烯基和硝基的致密官能化的环戊[ b ]吲哚啉。发现添加卤化物添加剂对反应的非对映选择性至关重要,这被认为是中间体之间快速进行π-σ-π互变的结果,从而可进行Curtin-Hammett控制。用4-取代的3-硝基吲哚观察到非对映选择性的转变以提供具有乙烯基和硝基基团彼此顺式的产物。
Fe-Catalyzed Allylic C–C-Bond Activation: Vinylcyclopropanes As Versatile a1,a3,d5-Synthons in Traceless Allylic Substitutions and [3 + 2]-Cycloadditions
作者:André P. Dieskau、Michael S. Holzwarth、Bernd Plietker
DOI:10.1021/ja300294a
日期:2012.3.21
The low-valent iron complex Bu(4)N[Fe(CO)(3)(NO)] (TBAFe) catalyzes the allylic C-C-bond activation of electron-poor vinyl cyclopropanes to generate syntheticallyuseful a1,a3,d5-synthons which are prone to undergo multiple consecutive reactions. The versatility of this approach is demonstrated by a traceless allylic substitution and a formal [3 + 2] cycloaddition to give either functionalized acyclic
Lewis acid catalyzed diastereoselective [3+4]-annulation of donor–acceptor cyclopropanes with anthranils: synthesis of tetrahydro-1-benzazepine derivatives
作者:Zhe-Hao Wang、Huan-Huan Zhang、Dao-Ming Wang、Peng-Fei Xu、Yong-Chun Luo
DOI:10.1039/c7cc04239f
日期:——
A Lewisacidcatalyzed [3+4]-annulation reaction between cyclopropane 1,1-diesters and anthranils has been developed. This annulation consists of a reaction sequence involving ring-opening/aromatization/nucleophilic addition. Thereinto, aromatization is the driving force for this annulation. Using this reaction, a series of 8-oxa-1-azabicyclo[3.2.1]octanes can be prepared conveniently with excellent
Palladium(0)-Catalyzed Dearomatization of 2-Nitrobenzofurans through Formal (3+2) Cycloadditions with Vinylcyclopropanes: A Straightforward Access to Cyclopenta[b]benzofurans
palladium-catalyzed dearomatization of electron-poor arenes, we report herein that various 2-nitrobenzofurans efficiently undergo a dearomative (3+2) cycloaddition with vinylcyclopropanes. This new method gives access to a wide variety of cyclopenta[b]benzofuran derivatives in a straightforward manner.
A straightforward entry to chiral carbocyclic nucleoside analogues is achievedviathe enantioselective [3+2] cycloaddition of α-nucleobase substituted acrylates to vinyl cyclopropanes.
Palladium-Catalyzed Diastereo- and Enantioselective Synthesis of Substituted Cyclopentanes through a Dynamic Kinetic Asymmetric Formal [3+2]-Cycloaddition of Vinyl Cyclopropanes and Alkylidene Azlactones
作者:Barry M. Trost、Patrick J. Morris
DOI:10.1002/anie.201101684
日期:2011.6.27
An enantioselective preparation of vinylcyclopentanes has been achieved through the title reaction (see scheme). A range of aryl, heterocyclic, alkenyl, and alkyl substitutedazlactonealkylidenes have been utilized, giving the cyclopentane products in good yield, diastereomeric ratio, and enantioselectivity.