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 Enantioselective Michael Addition of Silyl Nitronates to α,β-Unsaturated Aldehydes Catalyzed by Designer Chiral Ammonium Bifluorides: Efficient Access to Optically Active γ-Nitro Aldehydes and Their Enol Silyl Ethers
作者:Takashi Ooi、Kanae Doda、Keiji Maruoka
DOI:10.1021/ja0352810
日期:2003.7.1
Highly enantioselective Michaeladdition of silyl nitronates to α,β-unsaturated aldehydes has been accomplished by the utilization of designer N-spiro C2-symmetric chiral quaternary ammonium bifluoride 1 as an efficient catalyst, providing direct access to both optically active γ-nitro aldehydes, a very useful precursor to various complex organic molecules including aminocarbonyls, and their enol silyl
A New Imidazole-Containing Imidazolidinone Catalyst for Organocatalyzed Asymmetric Conjugate Addition of Nitroalkanes to Aldehydes
作者:Leila Hojabri、Antti Hartikka、Firouz Matloubi Moghaddam、Per I. Arvidsson
DOI:10.1002/adsc.200600316
日期:2007.3.5
Herein we report a new organocatalyst for the asymmetric Michael addition of nitroalkanes to α,β-unsaturatedaldehydes. This catalyst incorporates a basic imidazole group in addition to the secondary amine responsible for activation of the α,β-unsaturated carbonyl compounds via iminium ion formation. The new organocatalyst is capable of catalyzing the enantioselective carbon-carbon bond formation with
Evaluation of the Relationship between the Catalyst Structure and Regio- as well as Stereoselectivity in the Chiral Ammonium Bifluoride–Catalyzed Asymmetric Addition of Silyl Nitronates to α,β-Unsaturated Aldehydes
Unique relationship between the catalyst structure and regio- and stereoselectivity in the chiral quaternary ammonium bifluoride–catalyzed asymmetric addition of silyl nitronates to α,β-unsaturated aldehydes has been reported.
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 %.