Highly enantio- and chemo-selective 1,4-conjugate addition process of 5H-thiazol-4-ones with maleimides or 1,4-naphthoquinones, and 5H-oxazol-4-ones with maleimides were performed under a dipeptide-based tertiary amine (DP-UAA) catalyst. A series of valuable N,S- and N,O-containing heterocyclic compounds with excellent enantio- and disastereo-selectivities (up to >99% ee, > 20:1 dr) were attained.
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
Organocatalytic Asymmetric Mannich Reactions of 5<i>H</i>-Oxazol-4-ones: Highly Enantio- and Diastereoselective Synthesis of Chiral α-Alkylisoserine Derivatives
The first organocatalyticMannichreaction of 5H‐oxazol‐4‐ones with various readily prepared aryl‐ and alkylsulfonimides has been developed. Two commercially available pseudoenantiomeric Cinchona alkaloids‐derived tertiary amine/ureas have been demonstrated as the most efficient catalysts to access the opposite enantiomers of the Mannich products with equally excellent enantio‐ and diastereoselectivities
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...