epoxidized without formation of the corresponding amides. In addition, I could rapidly (≤10 min) catalyze epoxidation of various kinds of terminal, internal, and cyclic alkenes with H2O2 under the stoichiometric conditions. The mechanistic, spectroscopic, and kinetic studies showed that the I‐catalyzed epoxidation consists of the following three steps: 1) The reaction of I with H2O2 leads to reversible formation
甲二钒取代的磷钨,[γ-PW 10 ö 38 V 2(μ-OH)2 ] 3-(我),显示出最高的催化活性对H 2 ö 2中钒和钨络合物的乙酸烯丙酯的环氧化的基于营业额为210。在存在I的情况下,烯丙基位置带有乙酸盐,醚,羰基和氯基的各种缺电子烯烃可以高收率将其化学等价地氧化成相应的环氧化物,而等摩尔量的H 2 O 2关于基板。甚至丙烯腈和甲基丙烯腈也可以被环氧化而不形成相应的酰胺。另外,在化学计量比下,我可以快速(≤10分钟)用H 2 O 2催化各种末端,内部和环状烯烃的环氧化。的机理,光谱学,和动力学研究表明,我催化的环氧化反应由以下三个步骤组成:1)的反应我用H 2 ö 2所导致可逆形成一个氢过物种的[γ-PW 10 ö 38 V 2(μ-OH)(μ-OOH)] 3−(II),2)的连续脱水II形式的活性氧种与过氧组[γ-PW 10 ö 38 V 2(μ-η 2:η 2 -O 2)]
Titanium Salalen Catalysts Based on<i>cis</i>-1,2-Diaminocyclohexane: Enantioselective Epoxidation of Terminal Non-Conjugated Olefins with H<sub>2</sub>O<sub>2</sub>
Help for the neglected: Terminal, non‐conjugated olefins, such as 1‐octene, are difficult to epoxidize asymmetrically. Ti salalen complexes based on cis‐1,2‐diaminocyclohexane catalyze this demanding reaction giving high yields and enantioselectivities (up to 95 % ee), with H2O2 as the oxidant. The X‐ray structures of the μ‐oxo and peroxocomplexes shed light on the coordination behavior of this novel
被忽视的帮助:末端非共轭烯烃(例如1-辛烯)难以不对称环氧化。基于顺式1,2-二氨基环己烷的Ti salalen络合物以H 2 O 2为氧化剂,可催化要求苛刻的反应,从而提供高收率和对映选择性(最高95% ee)。μ-oxo和peroxo配合物的X射线结构阐明了这类新型配体的配位行为。
A discrete {Co<sub>4</sub>(μ<sub>3</sub>-OH)<sub>4</sub>}<sup>4+</sup>cluster with an oxygen-rich coordination environment as a catalyst for the epoxidation of various olefins
作者:Sun Young Lee、Namseok Kim、Myoung Mi Lee、Young Dan Jo、Jeong Mi Bae、Min Young Hyun、Sungho Yoon、Cheal Kim
DOI:10.1039/c5dt03422a
日期:——
A tetranuclear Co(ii) complex was active for epoxidation reactions of various olefins, and CoVO and CoIVO species were proposed to be the possible reactive intermediates.
Ultrasound-Assisted Epoxidation of Olefins and α,β-Unsaturated Ketones over Hydrotalcites Using Hydrogen Peroxide
作者:Unnikrishnan R. Pillai、Endalkachew Sahle-Demessie、Rajender S. Varma
DOI:10.1081/scc-120021028
日期:2003.7
Abstract An efficient ultrasound-assisted epoxidation of olefins and α,β-unsaturated ketones over hydrotalcite catalysts in the presence of hydrogenperoxide and acetonitrile is described. This general and selective protocol is relatively fast and is applicable to a wide variety of substrates.
Neighbouring effects on catalytic epoxidation by Fe-cyclam in M<sub>2</sub>-PDIxCy complexes
作者:Andreas J. Hofmann、Lukas Niederegger、Corinna R. Hess
DOI:10.1039/d0dt03758c
日期:——
unsymmetric PDIeCy ligand, featuring pyridinediimine and cylam sites, can be selectively metalated. Complementing the diiron compound, we have synthesized two heterobimetallic isomers, [ZnPDIFeCy(PDIeCy)(OTf)4] (3) and [FePDIZnCy(PDIeCy)(OTf)4] (4), and a dizinc complex, [Zn2(PDIeCy)(OTf)4] (5). Olefin epoxidation by the series of complexes was investigated. The M-PDI site influences the reactivity of