4-Substituted-α,α-diaryl-prolinols Improve the Enantioselective Catalytic Epoxidation of α,β-Enones
作者:Yawen Li、Xinyuan Liu、Yingquan Yang、Gang Zhao
DOI:10.1021/jo0617619
日期:2007.1.1
To seek novel metal-free organic catalysts for epoxidation with high stereoselectivity, a series of 4-substituted-α,α-diaryl-prolinols were synthesized in four steps from trans-4-hydroxyl-l-proline. These prolinol derivatives catalyzed the asymmetric epoxidation of α,β-enones to give the corresponding chiral epoxides in good yields and high enantioselectivities under mild reaction conditions. Studies
Diaryl-2-pyrrolidinemethanols catalyzed enantioselective epoxidation of α,β-enones: new insight into the effect of structural modification of the catalyst on reaction efficiency
作者:Alessandra Lattanzi、Alessio Russo
DOI:10.1016/j.tet.2006.10.005
日期:2006.12
Catalytic enantioselectiveepoxidation of α,β-unsaturated ketones promoted by diaryl-2-pyrrolidinemethanols and tert-butyl hydroperoxide (TBHP) is described. Investigation on structural modifications of the diaryl-2-pyrrolidinemethanols showed that fine tuning of the stereoelectronics of the substituents on the aryl moiety is important to achieve high efficiency. By employing a structurally optimized
Asymmetric Epoxidation of Enones Promoted by Dinuclear Magnesium Catalyst
作者:Joanna A. Jaszczewska‐Adamczak、Jacek Mlynarski
DOI:10.1002/adsc.202100482
日期:2021.9.7
still a challenging task. In this perspective, we present the application of chiral dinuclear magnesium complexes for asymmetricepoxidation of a broad range of electron-deficient enones. We demonstrate that the in situ generated magnesium-ProPhenol complex affords enantioenriched oxiranes in high yields and with excellent enantioselectivities (up to 99% ee). Our extensive study verifies the literature
Enantioselective (up to 87% ee) epoxidation of a variety of α,β-enones to form α,β-epoxy ketones is described using a series of fluorous α,α-diaryl-l-prolinols as bifuncational organocatalysts and tert-butyl hydrogenperoxide (TBHP) as an oxidant.
Asymmetric C–C bond formation via Darzens condensation and Michael addition using monosaccharide-based chiral crown ethers
作者:Péter Bakó、Zsolt Rapi、György Keglevich、Tamás Szabó、Péter L. Sóti、Tamás Vígh、Alajos Grűn、Tamás Holczbauer
DOI:10.1016/j.tetlet.2011.01.094
日期:2011.3
phase asymmetric Darzens condensations were promoted by d-glucose- and d-mannose-based crown ethers. The corresponding aromatic and heteroaromatic α,β-epoxyketones were obtained with moderate to high enantioselectivities (up to 96%) as well as diastereoselectivities (up to 98:2) under mild reaction conditions. The absolute configurations of several of the epoxyketones were determined by single crystal