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
A PPh3 mediated reductive annulation reactionbetweenisatins and 4,4-dicyano-2-methylenebut-3-enoates was developed. The reaction provided an alternative method for constructing five- and three-membered all-carbon spirooxindole compounds. Lithium chloride as a Lewis acid played a key role in the synthesis of spirocyclopentenyl oxindole compounds.
Regiodivergent construction of medium-sized heterocycles from vinylethylene carbonates and allylidenemalononitriles
作者:Xiang Zhang、Xiang Li、Jun-Long Li、Qi-Wei Wang、Wen-Lin Zou、Yan-Qing Liu、Zhi-Qiang Jia、Fu Peng、Bo Han
DOI:10.1039/c9sc06377c
日期:——
Here we report palladium-catalyzed, regiodivergent [5 + 4] and [5 + 2] annulations of vinylethylene carbonates and allylidenemalononitriles affording over 50 medium-sized heterocycles in high isolated yields with excellent regioselectivities.