Olefins were smoothly epoxidized under O2 (1 atm) in the presence of a hydrocarbon such as ethylbenzene or tetralin, using N-hydroxyphthalimide (NHPI) and Mo(CO)6 as catalyst; the present reaction involves autoxidation of the hydrocarbon assisted by NHPI and epoxidation of alkenes with the resulting hydroperoxide catalyzed by Mo(CO)6; cis-alkene was epoxidized in a stereospecific manner to form the
Manganese(II)/Picolinic Acid Catalyst System for Epoxidation of Olefins
作者:Ross A. Moretti、J. Du Bois、T. Daniel P. Stack
DOI:10.1021/acs.orglett.6b00518
日期:2016.6.3
An in situ generated catalyst system based on Mn(CF3SO3)2, picolinic acid, and peracetic acid converts an extensive scope of olefins to their epoxides at 0 °C in <5 min, with remarkable oxidant efficiency and no evidence of radical behavior. Competition experiments indicate an electrophilic active oxidant, proposed to be a high-valent Mn = O species. Ligand exploration suggests a general ligand sphere
基于Mn(CF 3 SO 3)2,吡啶甲酸和过氧乙酸的原位生成的催化剂体系在0°C下于<5分钟内将大量烯烃转化为环氧化物,具有显着的氧化效率并且没有自由基的迹象行为。竞争实验表明,一种亲电子活性氧化剂被认为是高价Mn = O物种。配体探索表明,一般的配体球基序有助于有效氧化。该方法以其简单性和使用廉价试剂来快速获得高附加值产品而得到强调。
Titanium<i>cis</i>-1,2-Diaminocyclohexane (<i>cis</i>-DACH) Salalen Catalysts for the Asymmetric Epoxidation of Terminal Non-Conjugated Olefins with Hydrogen Peroxide
Chiral Ti salalen complexes catalyze the asymmetric epoxidation of terminal non‐conjugated olefins with hydrogen peroxide. Modular ligands based on cis‐1,2‐diamino‐cyclohexane (cis‐DACH) were developed, giving high yields and enantiomeric excesses (ee, up to 96 %) at catalyst loadings as low as 0.1–0.5 mol %, and even under solvent‐free conditions.
Olefin-Dependent Discrimination between Two Nonheme HOFe<sup>V</sup>O Tautomeric Species in Catalytic H<sub>2</sub>O<sub>2</sub>Epoxidations
作者:Anna Company、Yan Feng、Mireia Güell、Xavi Ribas、Josep M. Luis、Lawrence Que、Miquel Costas
DOI:10.1002/chem.200802597
日期:2009.3.23
water incorporation into products (up to 75 %) is observed in epoxidation reactions with H2O2 by a bioinspired nonheme iron catalyst. A surprising substrate‐dependent incorporation of water is observed, and is proposed to arise from fast equilibrium betweentwo high‐valent HOFeVO isomeric species exhibiting different reactivity.
湿式加氧酶模型:在通过生物启发的非血红素铁催化剂与H 2 O 2进行的环氧化反应中,观察到前所未有的高水平的水混入产品(高达75%)。水的令人惊讶的衬底依赖性掺入观察到的,并提出了两个高价HO之间从快速平衡出现铁V表现出不同的反应性O异构体物种。