1713-33-3Relevant articles and documents
Direct formation of pinacols from olefins over various titano-silicates
Sasidharan,Wu, Peng,Tatsumi, Takashi
, p. 260 - 265 (2002)
The epoxidation and successive pinacol formation of tri- and tetraalkyl-substituted olefins using Ti-β/H2O2/H2O as the catalytic system has been investigated. Aluminum-free Ti-β exhibits better activity and pinacol selectivity than TS-1, TS-2, Ti-MCM-22, and mesoporous Ti-MCM-41. Pinacol (vic-diol) is obtained as the major product with small amounts of the side products pinacolone, alcohol (via hydration), and oligomers. The conversion and pinacol selectivity increase with an increase in reaction temperature and time. The change in product distribution with reaction time over Ti-β shows that the epoxide is the initial product which undergoes a secondary reaction to give pinacol as the major product. The conversion and H2O2 selectivity decrease with the bulkiness of the substituents at the C=C bond but the selectivity of pinacol is not significantly affected. The reactivity of cyclic 1-methyl-1-cyclohexene is considerably lower than that of the corresponding open-chain analogue 2-methyl-2-butene. The symmetrical tetramethyl-substituted 2,3-dimethyl-2-butene led to the formation of small amount of dimers over medium-pore titanium silicates TS-1, TS-2, and Ti-MCM-22. The epoxidation of these substituted olefins proceeded more rapidly when using acetonitrile as a cosolvent than under triphase conditions. Mechanistically, the primary epoxide product undergoes acid-catalyzed nucleophilic ring opening by H2O molecules to give pinacol.
Studies Relating to the Oxidative Degradation of Natural Rubber. The Autoxidation of 1-Methylcyclohexene: Primary Product Analysis, Allylic Hydroperoxide Isolation, and Regiochemistry of the Initial Events
Courtneidge, John L.,Bush, Melanie
, p. 1227 - 1229 (1989)
The autoxidation of 1-methylcyclohexene has been examined; the regiochemistry of the initial events has been defined by direct examination and isolation of the first-formed products and a synthetically useful method has been developed in which t-butyl hydroperoxide-loaded mixtures undergo rapid, low temperature autoxidation.
Epoxidation of Alkenes by 3-Bromo-4,5-dihydro-5-hydroperoxy-4,4-dimethyl-3,5-diphenyl-3H-pyrazole
Baumstark, Alfons L.,Pilcher, Robert S.
, p. 1141 - 1143 (1982)
-
Homogeneous catalytic oxidation of alkenes employing mononuclear vanadium complex with hydrogen peroxide
Maurya, Abhishek
, p. 3261 - 3269 (2020/07/14)
Abstract: Homogeneous liquid-phase oxidation of alkenes (allylbenzene, cis-cyclooctene, 4-chlorostyrene, styrene, 2-norbornene, 1-methyl cyclohexene, indene, lemonine, and 1-hexene) were catalyzed by using vanadium complex [VO(hyap)(acac)2] in existence of H2O2. The complex [VO(hyap)(acac)2] was formed as a crystal by the reaction of [VO(acac)2] and 2-hydroxyacetophenone (hyap) in the presence of methanol by refluxing the reaction mixture. Various analytical and spectroscopic techniques, namely FTIR, ESI–MS, UV–Vis, single-crystal XRD, and EPR, were used to analyze and optimize the structure of the complexes. Graphic abstract: [Figure not available: see fulltext.].
Pyrazine dicarboxylate-bridged arsenotungstate: Synthesis, characterization, and catalytic activities in epoxidation of olefins and oxidation of alcohols
Ma, Xinyi,He, Peipei,Xu, Baijie,Lu, Jingkun,Wan, Rong,Wu, Hechen,Wang, Yuan,Ma, Pengtao,Niu, Jingyang,Wang, Jingping
supporting information, p. 12956 - 12963 (2019/09/07)
A praseodymium(iii)-containing arsenotungstate K16H15Li7[Pr2(H2O)3(pzdc)As3W29O103]2·38H2O (1) (pzdc = pyrazine-2,3-dicarboxylic acid) was synthesized by a conventional aqueous solution method and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), and single crystal X-ray diffraction. Structural analysis revealed that compound 1 was constructed by two identical subunits {Pr2(H2O)3(AsW9O33)3W2O4} bridged together by two pzdc ligands. In addition, compound 1 could act as an efficient catalyst for the epoxidation of olefins and oxidation of alcohols with hydrogen peroxide (H2O2) as the oxidant. In particular, the turnover frequency (TOF) in the oxidation of 1-phenylethanol reached up to 10170 h-1, which is higher than that of previously reported catalysts.