Deracemization of (±)-cis-dialkyl substituted oxides via enantioconvergent hydrolysis catalysed by microsomal epoxide hydrolase
摘要:
Both enantiomers of cis-(+/-)-2,3-epoxyheptane 1a, cis-3,4-epoxyheptane 1b, cis-3,4-epoxynonane 1c, cis-3,4-epoxynonane-1-ol Id, and cis-1-methoxy-3,4-epoxynonane le undergo a highly stereoselective microsomal epoxide hydrolase catalysed hydration at the (S) carbon to give the corresponding three (R,R)-diol at complete conversion. A total kinetic resolution of racemic epoxides is also obtained with la and 1e. (C) 1998 Elsevier Science Ltd. All rights reserved.
Proton-Promoted and Anion-Enhanced Epoxidation of Olefins by Hydrogen Peroxide in the Presence of Nonheme Manganese Catalysts
作者:Chengxia Miao、Bin Wang、Yong Wang、Chungu Xia、Yong-Min Lee、Wonwoo Nam、Wei Sun
DOI:10.1021/jacs.5b11579
日期:2016.1.27
in the epoxidation of olefins by nonheme manganesecatalysts and aqueous hydrogen peroxide. More specifically, a mononuclear nonheme manganesecomplex bearing a tetradentate N4 ligand, Mn(II)(Dbp-MCP)(OTf)2 (Dbp-MCP = (1R,2R)-N,N'-dimethyl-N,N'-bis((R)-(3,5-di-tert-butyl-phenyl)-2-pyridinylmethyl)cyclohexane-1,2-diamine; OTf(-) = CF3SO3(-)), is a highly efficientcatalyst in the epoxidation of olefins
Iron(II) Complexes with Bio-Inspired N,N,O Ligands as Oxidation Catalysts: Olefin Epoxidation andcis-Dihydroxylation
作者:Pieter C. A. Bruijnincx、Inge L. C. Buurmans、Silvia Gosiewska、Marcel A. H. Moelands、Martin Lutz、Anthony L. Spek、Gerard van Koten、Robertus J. M. Klein Gebbink
DOI:10.1002/chem.200700573
日期:2008.1.28
iron(II) coordination chemistry of the ligands 3,3-bis(1-methylimidazol-2-yl)propionate (L1) and its neutral propyl ester analogue propyl 3,3-bis(1-methylimidazol-2-yl)propionate (PrL1). The molecular structures of two iron(II) complexes with PrL1 were determined and two different coordination modes of the ligand were observed. In [Fe(II)(PrL1)(2)](BPh(4))(2) (3) the ligand is facially coordinated to the metal
Iron-Catalyzed Olefin Epoxidation in the Presence of Acetic Acid: Insights into the Nature of the Metal-Based Oxidant
作者:Rubén Mas-Ballesté、Lawrence Que
DOI:10.1021/ja075115i
日期:2007.12.1
[BPMEN = N,N'-bis-(2-pyridylmethyl)-N,N'-dimethyl-1,2-ethylenediamine; TPA = tris-(2-pyridylmethyl)amine] catalyze the oxidation of olefins by H2O2 to yield epoxides and cis-diols. The addition of acetic acid inhibits olefin cis-dihydroxylation and enhances epoxidation for both 1 and 2. Reactions carried out at 0 degrees C with 0.5 mol % catalyst and a 1:1.5 olefin/H2O2 ratio in a 1:2 CH3CN/CH3COOH
catalyst containing a tetradentate ligand derived from triazacyclononane exhibits high catalytic activity in epoxidation reactions using peracetic acid as oxidant. The system exhibits broad substrate scope and requires small (0.1-0.15 mol %) catalyst loading. The catalyst is remarkably selective toward aliphatic cis-olefins. Mechanistic studies point toward an electrophilic oxidant delivering the oxygen
Highly Efficient Catalysts for Epoxidation Mediated by Iminium Salts
作者:Philip C. Page、Benjamin R. Buckley、Louise F. Appleby、Paul A. Alsters
DOI:10.1055/s-2005-918483
日期:——
A range of substituted dihydroisoquinolinium salts has been tested in the catalytic epoxidation of several alkenes. Catalyst loadings as low as 0.5 mol% have been used in the epoxidation of 1-phenylcyclohexene.