882-59-7Relevant academic research and scientific papers
Simple metal oxides as efficient heterogeneous catalysts for epoxidation of alkenes by molecular oxygen
Liang, Jun,Tang, Qinghu,Meng, Guanyu,Wu, Hongli,Zhang, Qinghong,Wang, Ye
, p. 1140 - 1141 (2004)
Magnetite iron oxide (Fe3O4) has been found to be an efficient heterogeneous catalyst for the epoxidation of alkenes by molecular oxygen in the absence of a sacrificial reductant among various transition metal oxides. The reaction probably proceeds via a radical mechanism.
A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles
Rossi-Fernández, Lucía,Dorn, Viviana,Radivoy, Gabriel
supporting information, p. 519 - 526 (2021/03/31)
A new heterogeneous catalytic system consisting of cobalt nanoparticles (CoNPs) supported on MgO and tert-butyl hydroperoxide (TBHP) as oxidant is presented. This CoNPs@MgO/t-BuOOH catalytic combination allowed the epoxidation of a variety of olefins with good to excellent yield and high selectivity. The catalyst preparation is simple and straightforward from commercially available starting materials and it could be recovered and reused maintaining its unaltered high activity.
Facile synthesis of libraries of functionalized cyclopropanes and oxiranes using ionic liquids – A new approach to the classical Corey-Chaykovsky reaction
Malunavar, Shruti S.,Sutar, Suraj M.,Prabhala, Pavankumar,Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Aridoss, Gopalakrishnan,Laali, Kenneth K.
supporting information, (2021/09/13)
The potential of [PAIM][NTf2]/BMIM-ILs as a base/solvent in the Corey-Chaykovsky reaction is demonstrated by the facile synthesis of libraries of functionalized cyclopropanes from enones and oxiranes from aldehydes and ketones, at room temperature in respectable isolated yields. To demonstrate their application, the synthesized epoxides were employed as substrates for the synthesis of a library of 2,3-disubstituted quinolines, using [BMIM(SO3H)][OTf]/[BMIM][PF6] as a catalyst/solvent. The potential for recycling/reuse of the IL solvents was also explored.
Oxidative Cleavage of Alkene C=C Bonds Using a Manganese Catalyzed Oxidation with H2O2 Combined with Periodate Oxidation
Mecozzi, Francesco,Dong, Jia Jia,Angelone, Davide,Browne, Wesley R.,Eisink, Niek N. H. M.
supporting information, p. 7151 - 7158 (2019/11/16)
A one-pot multi-step method for the oxidative cleavage of alkenes to aldehydes/ketones under ambient conditions is described as an alternative to ozonolysis. The first step is a highly efficient manganese catalyzed epoxidation/cis-dihydroxylation of alkenes. This step is followed by an Fe(III) assisted ring opening of the epoxide (where necessary) to a 1,2-diol. Carbon–carbon bond cleavage is achieved by treatment of the diol with sodium periodate. The conditions used in each step are not only compatible with the subsequent step(s), but also provide for increased conversion compared to the equivalent reactions carried out on the isolated intermediate compounds. The described procedure allows for carbon–carbon bond cleavage in the presence of other alkenes, oxidation sensitive moieties and other functional groups; the mild conditions (r.t.) used in all three steps make this a viable general alternative to ozonolysis and especially for use under flow or continuous batch conditions.
Retro-Corey-Chaykovsky Epoxidation: Converting Geminal Disubstituted Epoxides to Ketones
Li, Siqi,Li, Pingfan,Xu, Jiaxi
, (2019/09/13)
Corey-Chaykovsky epoxidation has been widely applied in the conversion of aldehydes and ketones to epoxides with sulfonium and sulfoxonium ylides. The reverse transformation is realized for conversion of geminal disubstituted epoxides to ketones in the presence of DABCO in refluxing mesitylene. The method is a weak basic transformation from epoxides to ketones with loss of a methylene group and can be applied as an alternative strategy of the acid-catalyzed Meinwald rearrangement or oxidation for conversion of epoxides to carbonyl compounds.
Continuous Flow Synthesis of Terminal Epoxides from Ketones Using in Situ Generated Bromomethyl Lithium
Von Keutz, Timo,Cantillo, David,Kappe, C. Oliver
supporting information, p. 10094 - 10098 (2019/12/24)
A scalable procedure for the direct preparation of epoxides from ketones has been developed. The method is based on the carefully controlled generation of (bromomethyl)lithium (LiCH2Br) from inexpensive CH2Br2 and MeLi in a continuous flow reactor. The reaction has shown excellent selectivity for a variety of substrates, including α-chloroketones, which typically fail under classic Corey-Chaykovsky conditions. This advantage has been used to develop a novel route toward the drug fluconazole.
QUINUCLIDINE DERIVATIVE
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Paragraph 0234; 0235; 0236; 0237; 0238, (2018/03/10)
Provided is a novel therapeutic agent for chronic obstructive pulmonary disease. Provided are a quinuclidine derivative and a medicament comprising the quinuclidine derivative. wherein R1 represents a hydrogen atom, a halogen atom, a lower alkyl group, a haloalkyl group, a lower alkoxy group, or a haloalkoxy group; Y represents —C(C═O)—O—, —CH2—, or —CH2O—; m represents an integer of 1 to 5; Z represents an oxygen atom or a sulfur atom; l represents a number of 0 or 1; n represents an integer of 0 to 4; X? represents an anion; and a substituent of a quinuclidine ring represents a 1,3-bond, or 1,4-bond, provided that when m is 3, l is 1, and n is 0, R1 represents a halogen atom, a lower alkyl group, a haloalkyl group, a lower alkoxy group, or a haloalkoxy group.
Rhenium complex-catalyzed Meinwald rearrangement reactions of oxiranes
Umeda, Rui,Muraki, Masahito,Nakamura, Yuudai,Tanaka, Tomoyuki,Kamiguchi, Kyohei,Nishiyama, Yutaka
supporting information, p. 2393 - 2395 (2017/05/29)
The Meinwald rearrangement reaction of oxiranes to the corresponding carbonyl compounds is efficiently catalyzed by the ReBr(CO)5 complex.
Substituent and Lewis Acid Promoted Dual Behavior of Epoxides towards [3+2]-Annulation Reactions with Donor-Acceptor Cyclopropanes: Synthesis of Substituted Cyclopentane and Tetrahydrofuran
Pandey, Ashok Kumar,Varshnaya, Rohit Kumar,Banerjee, Prabal
, p. 1647 - 1656 (2017/04/06)
Substituent and Lewis acid promoted generation of functionalized enolates from epoxides is developed. Divergent attack of the enolate on donor-acceptor cyclopropanes, i.e. C-attack or O-attack depending upon substituents present in both reacting partners, produced different products. C-attack gave functionalized cyclopentane derivatives, whereas O-attack furnished tetrahydrofuran derivatives through [3+2]-annulation reactions. Moreover, to increase the utility of our method, synthesized diastereomeric cyclopentane derivatives were converted into synthetically useful cyclopentene and cyclopentanone analogs.
Regioselective hydrosilylation of epoxides catalysed by nickel(II) hydrido complexes
Wenz, Jan,Wadepohl, Hubert,Gade, Lutz H.
supporting information, p. 4308 - 4311 (2017/04/21)
Bench-stable nickel fluoride complexes bearing NNN pincer ligands have been employed as precursors for the regioselective hydrosilylation of epoxides at room temperature. A nickel hydride assisted epoxide opening is followed by the cleavage of the newly formed nickel oxygen bond by σ-bond metathesis with a silane.
