18428-16-5Relevant articles and documents
Confined space-controlled hydroperoxidation of trisubstituted alkenes adsorbed on pentasil zeolites
Chen, Yu-Zhe,Wu, Li-Zhu,Zhang, Li-Ping,Tung, Chen-Ho
, p. 4676 - 4681 (2005)
Photosensitized oxidation of trialkylalkenes 2-methyl-2-pentene (1), 1-methylcyclohexene (2), trans-3-methyl-2-pentene (3), cis-3-methyl-2-pentene (4), and 2-methyl-2-butene (5) included in the internal framework of Na-ZSM-5 zeolites was investigated. The zeolite samples having adsorbed the alkenes were suspended in isooctane, and the sensitizer, tetraphenylporphyrin (TPP), was dissolved in the solution. Singlet oxygen produced in the solution diffused into the internal framework of the zeolites and reacted with alkenes. For all the substrates studied, the ene-type allylic hydroperoxides were obtained in a highly regioselective manner. The regiochemistry for 1-4 in favor of the allylic hydrogen abstraction from the largest substituents is in contrast to their photooxidation within the dye-supported zeolite Na-Y, where the secondary hydroperoxides are preferentially produced. The tight confinement of the alkenes within the narrow channels of the ZSM-5 zeolites is likely to be responsible for this selectivity.
Initiated, tert-Butyl Hydroperoxide-loaded, Low-temperature Autoxidation of Alkenes: A Chemoselective Synthesis of Allylic Hydroperoxides, allowing Analysis of the Regioselectivity of Hydrogen Atom Abstraction from some Unsymmetrically Substituted Substrates
Courtneidge, John L.,Bush, Melanie
, p. 1531 - 1538 (1992)
A method for the preparation of allylic hydroperoxides is introduced: the method involves the rapid, low-temperature, initiated autoxidation of an alkene (in these instances 1-methylcyclohexene and the isomeric 4-methyloct-4-enes) in the presence of tert-butyl hydroperoxide.The success of the method relies upon the selectivity of hydrogen atom abstraction from the substrate by the chain-carrying tert-butylperoxyl radicals, according to the preference for formation of the most stable intermediate allylic radicals, and the reduced rates of chain termination via thesesame radicals.The method gives a regioselectivity for attack broadly in agreement with predictions from Bolland's rules, and a sufficiently high chemoselectivity for allylic hydroperoxide formation that ready isolation of these products in good yields is achieved.
Controlling photoreactions with restricted spaces and weak intermolecular forces: Exquisite selectivity during oxidation of olefins by singlet oxygen
Natarajan, Arunkumar,Kaanumalle, Lakshmi S.,Jockusch, Steffen,Gibb, Corinne L. D.,Gibb, Bruce C.,Turro, Nicholas J.,Ramamurthy
, p. 4132 - 4133 (2007)
Highly regioselective photooxidation of methyl cycloalkenes has been performed in an aqueous medium by selectively blocking two of the three allylic hydrogens through supramolecular steric effect. Hydrophobic, steric, and weak intermolecular C-H-π interac
An entirely solvent-free photooxygenation of olefins under continuous flow conditions
Bayer, Patrick,Jacobi Von Wangelin, Axel
, p. 2359 - 2364 (2020/05/28)
Photooxygenations of alkenes with singlet oxygen are a versatile, atom-economical transformation. The choice of solvents is key to the success of this oxyfunctionalization with direct impact on the solubility of substrates, the lifetime of the reactive oxygen species, and the up-scaling of the process. We report an entirely solvent-free continuous-flow photooxygenation that operates at very high substrate/sensitizer ratios and enables high space-time yields.
Strategies for cleaner oxidations using photochemically generated singlet oxygen in supercritical carbon dioxide
Han, Xue,Bourne, Richard A.,Poliakoff, Martyn,George, Michael W.
scheme or table, p. 1787 - 1792 (2011/03/18)
Photochemically generated singlet oxygen, 1O2, has been reacted with four different substrates in supercritical carbon dioxide. By using fluorous surfactants and a co-solvent to solubilise more polar photosensitisers and reactants respectively, the applicability of the system is greatly enhanced. The Royal Society of Chemistry 2009.
