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
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.
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 %.
Efficient, Enantioselective Iminium Catalysis with an Immobilized, Recyclable Diarylprolinol Silyl Ether Catalyst
作者:Ina Mager、Kirsten Zeitler
DOI:10.1021/ol100166z
日期:2010.4.2
A highlyefficient approach for the synthesis, application, and recycling of immobilized diarylprolinol silyl ethers was developed. The MeOPEG-supported Jørgensen−Hayashi catalyst provides unchanged reactivity and selectivity as compared to the homogeneous catalyst, as demonstrated for the Michaeladdition of nitromethane to α,β-unsaturated aldehydes via iminium activation. In addition, the immobilization