one-pot, two-step process was disclosed for production of chiral α,β-epoxy ketonesfrom benzaldehydes and acetophenones catalyzed by imidazolium-modified poly(l-leucine). Two effective reaction systems with complementary high enantioselectivities (up to 98% ee) or satisfactory yields (up to 89%) have been developed. Importantly, the poly(aminoacid) catalyst can be easily recovered and recycled for ten
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
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.
Convenient Preparation of Chiralα,β-Epoxy Ketonesvia Claisen–Schmidt Condensation-Epoxidation Sequence
作者:Yongcan Wang、Jinxing Ye、Xinmiao Liang
DOI:10.1002/adsc.200600592
日期:2007.5.7
A novel Clasisen–Schmidt condensation-epoxidationsequence of aldehydes and ketones was developed to produce a series of chiral α,β-epoxy ketones under asymmetric phase-transfer catalytic conditions. The organocatalytic method reported here can afford chiral α,β-epoxy ketones under mild conditions with moderate to good yields and up to 96 % ee.
Enantioselective epoxidation of α,β-enones promoted by (1R,3S,4S)-2-azanorbornyl-3-methanol as an organocatalyst
作者:Jun Lu、Yun-He Xu、Feng Liu、Teck-Peng Loh
DOI:10.1016/j.tetlet.2008.07.175
日期:2008.10
(1R,3S,4S)-2-Azanorbornyl-3-methanol was synthesized form (R)-1-phenylethylamine and used as a catalyst for the enantioselectiveepoxidation of α,β-enones to afford the corresponding epoxides in good yields and high enantioselectivities at room temperature.