Biomimetic hydrogenation: a reusable NADH co-enzyme model for hydrogenation of α,β-epoxy ketones and 1,2-diketones
摘要:
A biomimetic method has been developed to transform alpha,beta-epoxy ketones or 1,2-diketones into corresponding beta-hydroxy ketones or alpha-hydroxy ketones using a catalytic amount of BNAH or BNA(+)Br(-). The regeneration of BNAH or BNA(+)Br(-) is achieved by a mixture of HCOOH/Et3N. A radical mechanism is proposed to explain these observations. (C) 2013 Elsevier Ltd. All rights reserved.
Solvent microstructure effect on reaction stereochemistry; ring opening of chalcone oxides
作者:Dana Durham、Charles A. Kingsbury
DOI:10.1039/p29860000923
日期:——
The stereochemistry and kinetics of acid-catalysed ring-opening reactions of epoxides are reported. Predominant inversion is found in the usual hydroxylic solvents. As the nucleophilicity of the solvent diminishes and acidity increases, the stereochemistry changes to predominant retention. Electron-donating substituents also tend to favour retention. In mixed solvents, the solvent microstructure is
Visible-Light-Driven Epoxyacylation and Hydroacylation of Olefins Using Methylene Blue/Persulfate System in Water
作者:Gabriela F. P. de Souza、Juliano A. Bonacin、Airton G. Salles
DOI:10.1021/acs.joc.8b01026
日期:2018.8.3
olefins in water using methylene blue as photoredox catalyst and persulfate as oxidant is reported. In this unprecedented unified approach, two different transformations are accomplished using only one set of reagents. The method has a broad scope spanning a range of aromatic and aliphatic aldehydes as well as conjugated and nonconjugated olefins to deliver ketones and epoxyketones from abundant and
1,1,2,2‐Tetrahydroperoxy‐1,2‐diphenylethane was used for the efficient and metal‐free epoxidation of various α,β‐unsaturated ketones, carried out under mild alkaline conditions at room temperature.
Facile epoxidation of α, β-unsaturated ketones with urea-2,2-dihydroperoxypropane as a new oxidant
作者:Kaveh Khosravi、Shirin Naserifar
DOI:10.1007/s13738-016-0980-1
日期:2017.2
AbstractVarious aromatic α, β-unsaturatedketones were successfully transformed into their corresponding epoxides using urea-2,2-dihydroperoxypropane as the oxygen source for the first time. The reactions were carried out under mild alkaline conditions at room temperature in high yields and short reaction times. Graphical Abstract
Facile epoxidation of α,β-unsaturated ketones with cyclohexylidenebishydroperoxide
作者:Kavitha Jakka、Jinyun Liu、Cong-Gui Zhao
DOI:10.1016/j.tetlet.2006.12.104
日期:2007.2
Cyclohexylidenebishydroperoxide was successfully used as the oxygen source for the oxidation of α,β-unsaturatedketones for the first time. The corresponding epoxides were obtained in excellent yields under the Weitz–Scheffer reaction conditions.