Direct Sulfide-Catalyzed Enantioselective Cyclopropanations of Electron-Deficient Dienes and Bromides
作者:Qing-Zhu Li、Xiang Zhang、Rong Zeng、Qing-Song Dai、Yue Liu、Xu-Dong Shen、Hai-Jun Leng、Kai-Chuan Yang、Jun-Long Li
DOI:10.1021/acs.orglett.8b01537
日期:2018.6.15
A catalytic highly regioselective, diastereoselective, and enantioselective cyclopropanation of electron-deficient dienes and bromides via direct sulfide organocatalysis is reported. A variety of vinylcyclopropanes featuring a quaternary chiral center were synthesized in up to 99% yield and up to 98:2 enantiomeric ratio (er). These products could be facilely transformed to various interesting molecules
Heterogeneous Bifunctional Catalytic, Chemo-, Regio- and Enantioselective Cascade Inverse Electron Demand Diels-Alder Reaction
作者:Xianxing Jiang、Hao Zhu、Xiaomei Shi、Yuan Zhong、Yanfeng Li、Rui Wang
DOI:10.1002/adsc.201201038
日期:2013.1.25
We present a bifunctionalcatalytic, chemo-, regio- and enantioselectiveinverseelectrondemandDiels–Alderreaction (IEDDAR) cascade of a variety of methylenebut-3-enoates with azlactones at high levels of yield and enantioselectivity (up to 99% yield, and >99% ee) via a dual HOMOdienophiles and LUMOdienes activated pathway using a heterogeneouscatalytic system. Meanwhile, a novel MNPs-supported
Asymmetric Sulfur-Ylide-Mediated Formal [4+1]-Annulation Reaction: Scope and Mechanism
作者:Sébastien Clergue、Olivier Rousseau、Thierry Delaunay、Geoffroy Dequirez、Trieu-Van Tran、Soumia El Aakchioui、Gabriella Barozzino-Consiglio、Raphaël Robiette
DOI:10.1002/chem.201801874
日期:2018.8.6
A formal [4+1]‐annulation strategy between sulfurylides and 1,3‐dienes was developed to afford functionalized cyclopentanoids. The process consists of a stereoselective cyclopropanation reaction followed, in situ, by a stereospecific MgI2‐catalyzed vinylcyclopropane–cyclopentene rearrangement. The use of chiral sulfurylides provided cyclopentanoids with excellent enantiocontrol. A combined experimental
开发了一种在硫醚和1,3-二烯之间形成正式的[4 + 1]环化策略,以提供功能化的环戊烷类化合物。该过程包括立体选择性环丙烷化反应,然后原位进行立体特异性MgI 2催化的乙烯基环丙烷-环戊烯重排。手性硫的使用为环戊烷提供了优异的对映体控制能力。结合实验和计算机理的研究表明,重排的立体特异性可以由涉及碘化物的双重S N 2反应机理解释。
Phosphine-catalyzed [4+1] annulation of 1,3-(aza)dienes with maleimides: highly efficient construction of azaspiro[4.4]nonenes
作者:Mei Yang、Tianyi Wang、Shixuan Cao、Zhengjie He
DOI:10.1039/c4cc05624h
日期:——
Phosphine-catalyzed [4+1] annulation of electron-deficient 1,3-dienes or 1,3-azadienes with maleimides has been successfully developed under very mild conditions, providing a convenient and highly efficient method for constructing 2-azaspiro[4.4]nonenes and 1,7-diazaspiro[4.4]nonenes. This reaction represents the first example of [4+1] cyclization between electron-deficient 4pi-conjugated systems and
Diastereodivergent synthesis of cyclopropanes <i>via</i> on-water [2 + 1] annulations of diazo compounds with electron-deficient alkenes
作者:Qing-Zhu Li、Xiang Zhang、Ke Xie、Qing-Song Dai、Rong Zeng、Yan-Qing Liu、Zhi-Qiang Jia、Xin Feng、Jun-Long Li
DOI:10.1039/c9gc00278b
日期:——
cyclopropanation of diazo compounds and electron-deficient alkenes under metal- and catalyst-freeconditions was developed. The use of water as the sole solvent dramatically increased the efficiency of the reaction. This on-water synthesis approach featured numerous advantages, including high yield, broad substrate scope and environmentally friendly conditions. Moreover, a simple substrate-engineering strategy was