4478-63-1Relevant articles and documents
Neighbouring effects on catalytic epoxidation by Fe-cyclam in M2-PDIxCy complexes
Hofmann, Andreas J.,Niederegger, Lukas,Hess, Corinna R.
supporting information, p. 17642 - 17648 (2020/12/30)
The 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 the M-cyclam, resulting in increased activity toward enones. This journal is
Olefins oxidation with molecular O2 in the presence of chiral Mn (III) salen complex supported on magnetic CoFe2O4@SiO2@CPTMS
Hemmat, Kaveh,Nasseri, Mohammad A.,Allahresani, Ali
, (2019/04/26)
In the present study, CoFe2O4@SiO2@CPTMS nanocomposite was synthesized and the homogeneous chiral Mn-salen complex was anchored covalently onto the surface of CoFe2O4@SiO2@CPTMS nanocomposite. The heterogeneous Mn-salen magnetic nanocatalyst (CoFe2O4@SiO2@CPTMS@ chiral Mn (III) Complex) was characterized by different techniques including transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Then, the aerobic enantioselective oxidation of olefins to the corresponding epoxide was investigated in the presence of magnetic chiral CoFe2O4@SiO2@Mn (III) complex at ambient conditions within 90?min. The results showed the corresponding products were synthesized with excellent yields and selectivity. In addition, the heterogeneous CoFe2O4@SiO2@ CPTMS@ chiral Mn (III) complex has benefits such as high selectivity and comparable catalytic reactivity with its homogeneous analog as well as mild reaction condition, facile recovery, and recycling of the heterogeneous catalyst.
Metal-Free and Efficient Epoxidation of α,β-Unsaturated Ketones with 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane as a Powerful Solid Oxidant
Khosravi, Kaveh,Naserifar, Shirin,Mahmoudi, Boshra
, p. 683 - 689 (2017/06/19)
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.
Oxidation of olefins using molecular oxygen catalyzed by a part per million level of recyclable copper catalyst under mild conditions
Yang, Guoqiang,Du, Huiyuan,Liu, Jia,Zhou, Zheng,Hu, Xingbang,Zhang, Zhibing
, p. 675 - 681 (2017/08/14)
Copper catalysts with an imidazole salt tag ([Cu-Imace-R-H][X], X- = F-, Cl-, Br-, I-, CF3CO2-, HSO4-, NO3-, PF6- or BF4-; R = H or CH3) show quite high reactivity for the oxidation of non-aromatic olefins with good selectivity for epoxides. The reactions perform well with a part per million (ppm) catalyst loading at mild temperature and ambient pressure. The highest turnover frequency (TOF) reaches up to 900:000 h-1. The catalytic activity is easy to control by changing the anion of [Cu-Imace-R-H][X]. This catalyst is effective for a series of substrates, including internal and terminal olefins, tri- and tetra-substituted olefins and aromatic olefins. In addition, the copper catalyst can be conveniently separated from the reaction system and reused for at least six cycles without any obvious loss of catalytic activity.
The cinchona primary amine-catalyzed asymmetric epoxidation and hydroperoxidation of α,β-unsaturated carbonyl compounds with hydrogen peroxide
Lifchits, Olga,Mahlau, Manuel,Reisinger, Corinna M.,Lee, Anna,Fares, Christophe,Polyak, Iakov,Gopakumar, Gopinadhanpillai,Thiel, Walter,List, Benjamin
supporting information, p. 6677 - 6693 (2013/06/05)
Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogen peroxide as the oxidant, we have developed highly enantioselective Weitz-Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonyl compounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5-15-membered cyclic enones, and α-branched enals as substrates. In addition to an expanded scope, synthetic applications of the products are presented. We also report detailed mechanistic investigations of the catalytic intermediates, structure-activity relationships of the cinchona amine catalyst, and rationalization of the absolute stereoselectivity by NMR spectroscopic studies and DFT calculations.
Epoxidation of alkenes with aqueous hydrogen peroxide and quaternary ammonium bicarbonate catalysts
Mielby, Jerrik,Kegnaes, Soren
, p. 1162 - 1165 (2014/01/06)
A range of solid and liquid catalysts containing bicarbonate anions were synthesised and tested for the epoxidation of alkenes with aqueous hydrogen peroxide. The combination of bicarbonate anions and quaternary ammonium cations opens up for new catalytic systems that can help to overcome challenges with catalyst separation and reuse. Graphical Abstract: [Figure not available: see fulltext.]
Novel basic ionic liquid based on alkylammonium as efficient catalyst for Knoevenagel reaction
Zhou, Shuai,Liu, Lu,Wang, Bo,Ma, Mingguo,Xu, Feng,Sun, Runcang
experimental part, p. 1384 - 1391 (2012/04/10)
The typical Knoevenagel condensation was carried out smoothly in the presence of a basic ionic liquid of N,N,N′,N′-tetramethyl-N′- hexyl-ethylenediammonium tetrafluoroborate ([TMHEDA]BF4), and 99% of yield was obtained using ethyl cyanoacetate and benzaldehyde as substrates at 60 °C for 1 h. Four reuses of the ionic liquid without dramatic decrease in catalytic activity for Knoevenagel condensation demonstrated the good stability and operability of the ionic liquid. Moreover, the typical nucleophilic addition reactions were also accomplished by the same ionic liquid to check its feasibility. The dual function of the basic ionic liquid both as solvent and catalyst, combined with simple product separation and recycling, is expected to contribute to the development of a green and environmentally friendly strategy. Copyright Taylor & Francis Group, LLC.
Amino-acid-mediated epoxidation of α,β-unsaturated ketones by hydrogen peroxide in aqueous media
Kim, Juhyun,Jung, Suhyun,Park, Seongsoon,Park, Sojung
experimental part, p. 2866 - 2868 (2011/06/21)
Amino acids, such as arginine and lysine, can be used as an efficient catalyst in the epoxidation of α,β-unsaturated ketones with aqueous hydrogen peroxide. Up to >99% conversion was obtained in the reaction toward 11 α,β-unsaturated ketones.
Mesoporous SBA-15 materials modified with PW or W active species as catalysts for the epoxidation of olefins with H2O2
Zhang, Aiping,Zhang, Yi,Wang, Puguang,Li, Jun,Lv, Ying,Gao, Shuang
experimental part, p. 975 - 984 (2012/05/20)
Five catalysts containing PW or W active species that anchored onto aminosilylated mesoporous silica SBA-15 by a post-grafting route were prepared and the resulting PW or W/APTES/SBA-15 hybrid materials were characterized by XRD, N2 adsorption/desorption, surface area analysis, TEM, FT-IR, and ICP (inductively coupled plasma atomic emission spectroscopy). The names of these catalysts have been abbreviated as SBA-15m-a, SBA-15m-b, SBA-15m-c, SBA-15m-d, and SBA-15m-e according to the different active species. The PW or W active species were highly dispersed in the channels of the modified mesoporous materials. The interaction between PW or W species and amino groups grafted on the channel surface of SBA-15 led to the immobilization of PW or W species. Their catalytic activity in the epoxidation of cyclooctene with H 2O2 as oxidant was investigated. Among them, SBA-15m-a showed the best performance, with 98.9% conversion and 98.4% selectivity. The catalyst could be reused for six times with a little decrease in activity.
Epoxidation of olefins with O2 and isobutyraldehyde catalyzed by cobalt (II)-containing zeolitic imidazolate framework material
Zhang, Aiping,Li, Linqing,Li, Jun,Zhang, Yi,Gao, Shuang
experimental part, p. 1183 - 1187 (2012/05/20)
Co-containing zeolitic imidazolate framework material (Co-ZIF) was prepared and its catalytic performance in the aerobic epoxidation of olefins using isobutyraldehyde as reductant under mild conditions was first studied. Co-ZIF was characterized by XRD, FT-IR and X-ray single-crystal diffraction. It showed good performance in the epoxidation of olefins, with 100% conversion, 98.5% selectivity and 638.3 turnover frequency for the epoxidation of cyclooctene. Co-ZIF could be reused for 5 times without loss of its catalytic activity and the structure of the recovered catalyst was almost unchanged compared to that of the fresh one.
