Highly Diastereo- and Enantioselective Synthesis of α-Alkyl Norstatine Derivatives: Catalytic Asymmetric Mannich Reactions of 5H-Oxazol-4-ones
作者:Depeng Zhao、Linqing Wang、Dongxu Yang、Yixin Zhang、Rui Wang
DOI:10.1002/anie.201201804
日期:2012.7.23
Going Mannich: The title reaction results in the first catalyticasymmetricsynthesis of syn‐α‐alkyl norstatine derivatives. Excellent enantioselectivities and diastereoselectivities were achieved with a series of N‐diphenylphosphinoyl‐protected imines and 5H‐oxazol‐4‐ones by using the catalyst 1/Zn. Importantly, the involvement of the diethyl phosphoramidate 2 was critical to achieve good enantioselectivities
Highly diastereoselective and enantioselective Michael addition of 5H-oxazol-4-ones to α,β-unsaturated ketones catalyzed by a new bifunctional organocatalyst with broad substrate scope and applicability
作者:Huicai Huang、Kailong Zhu、Wenbin Wu、Zhichao Jin、Jinxing Ye
DOI:10.1039/c1cc15928c
日期:——
A new thiourea-tertiary amine bifunctional catalyst derived from L-tert-leucine was developed and provides excellent stereocontrol in a novel and direct Michaeladdition of 5H-oxazol-4-ones to alpha,beta-unsaturated ketones with much broad substrate scope. The conjugate addition products with chiral vicinal quaternary and tertiary stereocenters can be easily transformed to structurally interesting
Non-hydrogen bond catalyst-mediated diastereoselective conjugate additions of 5<i>H</i>-oxazol-4-ones to <i>o</i>-hydroxyphenyl-substituted <i>p</i>-quinone methides
作者:Ziyang Wang、Anqi Huang、Fang Fang、Pengfei Li、Guokai Liu、Wenjun Li
DOI:10.1039/d0ob01558j
日期:——
An efficient DBU-catalyzed conjugateaddition of 5H-oxazol-4-ones to o-hydroxyphenyl-substituted p-quinone methides has been developed, affording the valuable diarylmethanes in high yields with excellent diastereoselectivity. This strategy demonstrates a robust access to a wide range of diarylmethane derivatives possessing biologically significant o-hydroxyphenol and p-hydroxyphenol moieties under
Highly enantioselective allylic alkylation of 5 H -oxazol-4-ones with Morita-Baylis-Hillman carbonates
作者:Han Xu、Feng Sha、Xin-Yan Wu
DOI:10.1016/j.tet.2018.06.055
日期:2018.8
An organocatalytic enantioselectiveallylicalkylation of 5H-oxazol-4-ones with Morita-Baylis-Hillman carbonates has been developed. With 10 mol% of commercially available cinchonidine, a wide range of substituted 5H-oxazol-4-one derivatives were constructed in good-to-excellent yields with high diastereo- and enantioselectivities. The allylicalkylation adducts obtained are valuable precursors for
Catalyst-controlled switch of regioselectivity in the asymmetric allylic alkylation of oxazolones with MBHCs
作者:Gongming Zhu、Junxian Yang、Guangjun Bao、Ming Zhang、Jing Li、Yiping Li、Wangsheng Sun、Liang Hong、Rui Wang
DOI:10.1039/c6cc03246j
日期:——
A catalyst-controlled switch of regioselectivity in asymmetric allylicalkylation of oxazolones with MBHCs was described. The proper choice of catalysts could differentiate the SN2'-SN2' and addition-elimination process to yield secondary...