Chiral Ionic Liquids Bearing O-Silylated α,α-Diphenyl (S)- or (R)-Prolinol Units: Recoverable Organocatalysts for Asymmetric Michael Addition of Nitroalkanes to α,β-Enals
作者:Oleg V. Maltsev、Alexandr S. Kucherenko、Irina P. Beletskaya、Vladimir A. Tartakovsky、Sergei G. Zlotin
DOI:10.1002/ejoc.201000239
日期:2010.5
Chiral ionicliquids bearing O-silylated α,α-diphenyl (S)- or (R)-prolinol units tagged to the imidazolium cation were synthesized and their activity as catalysts in the Michael addition of nitroalkanes to α,β-unsaturated aldehydes was evaluated. Respective (S) or (R) adducts were obtained in the reactions in high yields (up to 95 %) and with high enantioselectivity (up to 99 % ee). Remarkably, the
合成了带有标记到咪唑鎓阳离子的 O-甲硅烷基化 α,α-二苯基 (S)-或 (R)-脯氨醇单元的手性离子液体,并评估了它们在硝基烷烃与 α,β-不饱和醛的迈克尔加成反应中作为催化剂的活性. 在反应中以高产率(高达 95%)和高对映选择性(高达 99%ee)获得了相应的 (S) 或 (R) 加合物。值得注意的是,固定化的有机催化剂可以使用五次而不会降低产品产率或 ee 值。(R)-Michael 加合物可以很容易地转化为药物 Phenibut、巴氯芬和咯利普兰的最活跃的 (R) 对映异构体,用于治疗中枢神经系统疾病。
Highly Active Water-Soluble and Recyclable Organocatalyst for the Asymmetric 1,4-Conjugate Addition of Nitroalkanes to α,β-Unsaturated Aldehydes
作者:Subrata K. Ghosh、Zilong Zheng、Bukuo Ni
DOI:10.1002/adsc.201000344
日期:2010.10.4
A novel strategy for the catalyticasymmetric conjugate addition of nitroalkanes to α,β-unsaturatedaldehydes in aqueous media has been developed by using diarylprolinol silyl ether in combination with benzoic acid as a water-soluble organocatalyst providing the desired adducts in good to excellent enantioselectivities (up to 95% ee). This catalyst can be recycled at least five times with only a slight
Remote Sulfonamido Group Enhances Reactivity and Selectivity for Asymmetric Michael Addition of Nitroalkanes to α,β-Unsaturated Aldehydes
作者:Yu-Chao Huang、Biing-Jiun Uang
DOI:10.1002/asia.201402516
日期:2014.9
The pyrrolidine–camphorsulfonamide‐based catalyst 1 a catalyzes the enantioselectiveconjugateaddition of nitroalkanes to α,β‐unsaturated aldehydes in the presence of five equivalents of water in iPrOH to give the corresponding chiral Michael adducts in good yields and high enantioselectivities (up to 99 % ee) with a catalystloading as low as 1 mol %.
Asymmetric Synthesis of γ-Nitroesters by an Organocatalytic One-Pot Strategy
作者:Kim L. Jensen、Pernille H. Poulsen、Bjarke S. Donslund、Fabio Morana、Karl Anker Jørgensen
DOI:10.1021/ol3002514
日期:2012.3.16
An enantioselective synthesis of γ-nitroesters by a one-pot asymmetric Michaeladdition/oxidative esterification of α,β-unsaturatedaldehydes is presented. The procedure is based on merging the enantioselective organocatalytic nitroalkane addition with an N-bromosuccinimide-based oxidation. The γ-nitroesters are obtained in good yields and enantioselectivities, and the method provides an attractive
An efficient enantioselective method for asymmetric Michael addition of nitroalkanes to α,β-unsaturated aldehydes
作者:Yongcan Wang、Pengfei Li、Xinmiao Liang、Tony Y. Zhang、Jinxing Ye
DOI:10.1039/b717000a
日期:——
The addition of nitroalkanes to alpha,beta-unsaturated aldehydes under the catalysis of (S)-2-(diphenyl(trimethylsilyloxy)methyl)pyrrolidine and lithium acetate as additive afforded gamma-nitroaldehydes in good yield and up to 97% ee.