56595-77-8Relevant academic research and scientific papers
Sunlight induced oxidative photoactivation of N-hydroxyphthalimide mediated by naphthalene imides
Melone, Lucio,Franchi, Paola,Lucarini, Marco,Punta, Carlo
, p. 3210 - 3220 (2013/12/04)
We report the aerobic photoactivation of N-hydroxyphthlimide (NHPI) to the phthalimido-N-oxyl (PINO) radical mediated by naphthalene monoimides (NI) for promoting the selective oxidation of alkylaromatics and allylic compounds to the corresponding hydroperoxides. In the absence of either NI or NHPI no oxidation was observed, meaning that the two molecules operate in a synergistic way. Sunlight as well as artificial UV-light irradiation was necessary in order to perform the process at low temperature (30-35 °C). EPR spectroscopy confirmed the role of NI and oxygen in promoting the formation of the superoxide radicals O2.- which, in turn, increased the concentration of PINO radicals during the UV light irradiation of NI/NHPI mixtures in MeCN. The investigation was extended to NI bearing different substituents on the naphthalene moiety. Finally, the synthesis and application of a unique photocatalyst including the NI and NHPI moieties linked by a suitable spacer was also considered. In this case the photocatalyst showed a substrate-dependent behaviour with some peculiarities in comparison to the system where NI and NHPI are independent units in the same reacting system. This photocatalytic system paves the way to a non-thermal, metal-free approach for C-H bond activation towards aerobic oxidation under very mild conditions. Copyright
Initiated tert-Butyl Hydroperoxide-loaded Low-temperature Autoxidation of Alkenes: Alternative Hydroperoxide Syntheses and the Preparation of a Complete Set of Reference Material
Courtneidge, John L.,Bush, Melanie,Loh, Lay-See
, p. 1539 - 1548 (2007/10/02)
A complete set of characterization data for the allylic hydroperoxides prepared from 1-methylcyclohexene and the isomeric 4-methyloct-4-enes is presented.The data relies upon the preparation of allylic hydroperoxides by tert-butyl hydroperoxide-loaded autoxidations, singlet-ene oxidations and nucleophilic substitution reactions.Appropriate allylic alcohols and relevant scission products have been prepared to support the assignments given.
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 (2007/10/02)
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.
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 (2007/10/02)
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.
REACTIVITY OF CYCLOALKENES.
Azhikova,Syroezhko,Proskuryakov
, p. 2133 - 2140 (2007/10/02)
The objective of this work is to investigate the kinetic relationships, to determine the composition of the products, and to elucidate the mechanism of their formation during liquid-phase oxidation of cyclohexene and of isomeric methylcyclohexenes (RH). Experiments show that the main products of oxidation of cyclohexene and of isomeric methylcyclohexenes are mixtures of hydroperoxides, unsaturated alcohols, ketones, and oxides. The isomeric methylcyclohexenes form the following series in order to selectivity of formation of methylcyclohexenols: 3-methylcyclohexene greater than 1-methylcyclohexene greater than 4-methylcyclohexene greater than cyclohexene; the corresponding series for alpha -oxide formation is 1-methylcyclohexene greater than 4-methylcyclohexene greater than 3-methylcyclohexene. A mathematical model of noncatalytic oxidation of cyclohexene has been formulated, and the rate constants of the process have been determined.
Studies on the Autoxidation of Some Monocyclic Olefins
Blau, K.,Mueller, U.,Pritzkow, W.,Schmidt-Renner, W.,Sedshaw, Z.
, p. 915 - 932 (2007/10/02)
The autoxidations of cyclopentene, cyclohexene, cycloheptene, cyclooctene, cycloocta-1,5-diene, 1-methylcyclopentene, 1-methylcyclohexene, 1-methylcycloheptene, 1-methylcyclooctene, methylene cyclopentene, and methylene cyclohexene with pure oxygen under normal pressure were studied.The epoxides formed were determined gaschromatographically.In most cases also the products of allylic oxidation were analyzed and their structures elucidated after reduction to the corresponding allyl alcohols.The portions of high boiling or polymeric products which could not be detected gaschromatographically and also the real yields of epoxides were determined by balance experiments in the presence of inert internal standards.
