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
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.
A highly efficient catalytic kinetic resolution of 2,3-epoxy 3-aryl ketones via asymmetric ring-opening with pyrazole derivatives has been achieved by using a chiral N,N′-dioxide–Sc(iii) complex as the catalyst.
Highly Enantioselective Epoxidation of Multisubstituted Enones Catalyzed by Non‐Heme Iron Catalysts
作者:Bin Wang、Shoufeng Wang、Chungu Xia、Wei Sun
DOI:10.1002/chem.201200992
日期:2012.6.11
Iron(II) efficiency: The iron complexes of N4 ligands, derivedfrom proline and benzimidazole, exhibited an unprecedented activity and enantioselectivity for the epoxidation of a variety of di‐ and trisubstituted enones (see scheme). This system, based on synthetic non‐heme iron catalysts, provides ready access to a wide range of epoxyketones of high enantiomeric purity.