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。
Polystyrene-Supported Diarylprolinol Ethers as Highly Efficient Organocatalysts for Michael-Type Reactions
作者:Esther Alza、Sonia Sayalero、Pinar Kasaplar、Diana Almaşi、Miquel A. Pericàs
DOI:10.1002/chem.201101730
日期:2011.10.4
addition of aldehydes to nitroolefins and of malonates or nitromethane to α,β‐unsaturated aldehydes. The combination of the catalytic unit, the triazole linker, and the polymeric matrix provides unprecedented substrate selectivity, in favor of linear, short‐chain aldehydes, when the organocatalyzed reaction proceeds by an enamine mechanism. High versatility is noted in reactions that proceed via an iminium
Telescoped Continuous Flow Synthesis of Optically Active γ-Nitrobutyric Acids as Key Intermediates of Baclofen, Phenibut, and Fluorophenibut
作者:Sándor B. Ötvös、Patricia Llanes、Miquel A. Pericàs、C. Oliver Kappe
DOI:10.1021/acs.orglett.0c03100
日期:2020.10.16
The two-step flow asymmetric synthesis of chiral γ-nitrobutyric acids as key intermediates of the GABA analogues baclofen, phenibut, and fluorophenibut is reported on a multigram scale. The telescoped process comprises an enantioselective Michael-type addition facilitated by a polystyrene-supported heterogeneous organocatalyst under neat conditions followed by in situ-generated performic acid-mediated
Ionic polymer-supported O-trimethylsilyl-α,α-diphenyl-(S)-prolinols as recoverable organocatalysts for the asymmetric Michael reactions of carbon acids with α,β-enals
作者:Oleg V. Maltsev、Alexander S. Kucherenko、Sergei G. Zlotin
DOI:10.1016/j.mencom.2011.04.011
日期:2011.5
A recyclable organocatalyst bearing O -trimethylsilyl-α,α-diphenyl-( S )-prolinol unit tagged to the imidazolium cation and poly(4-styrenesulfonate) anion in the reaction of CH-acids with α,β-enals provided the respective Michael adducts in high yields (up to 99%) and with high enantioselectivities (up to 98% ee ).
Highly Enantioselective Organocatalytic Conjugate Addition of Nitromethane to α,β-Unsaturated Aldehydes: Three-Step Synthesis of Optically Active Baclofen
作者:Liansuo Zu、Hexin Xie、Hao Li、Jian Wang、Wei Wang
DOI:10.1002/adsc.200700353
日期:2007.12.10
An efficient, organocatalytic, highlyenantioselective, conjugateaddition reaction of nitromethane with α,β-unsaturated aldehydes has been developed. The process serves as the key step for a practical 3-step synthesis of chiral baclofen, an antispastic drug.