Topic
Cyclohexanone
About: Cyclohexanone is a research topic. Over the lifetime, 7205 publications have been published within this topic receiving 99572 citations. The topic is also known as: Anone & Cyclohexyl ketone.
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TL;DR: The solid Lewis acid Sn-zeolite β is obtained in a simple and scalable procedure (see scheme) and a high metal content can be obtained, without undesirable side-effects.
Abstract: Tin goes in: The solid Lewis acid Sn-zeolite β is obtained in a simple and scalable procedure (see scheme). A high metal content can be obtained, without undesirable side-effects. The space-time-yields of the resulting catalysis are over one order-of-magnitude larger than those of the state-of-the-art materials for the Baeyer–Villiger oxidation of cyclohexanone and the synthesis of ethyl lactate from the triose dihydroxyacetone.
283 citations
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TL;DR: Framework-substituted, molecular-sieve, aluminophosphate, microporous solids are the centerpieces of a new approach to the aerobic oxyfunctionalization of saturated hydrocarbons.
Abstract: Framework-substituted, molecular-sieve, aluminophosphate, microporous solids are the centerpieces of a new approach to the aerobic oxyfunctionalization of saturated hydrocarbons. The sieves, and the few percent of the AlIII sites within them that are replaced by catalytically active, transition-metal ions in high oxidation states (CoIII, MnIII, FeIII), are designed so as to allow free access of oxygen in to and out of the interior of these high-area solids. Certain metal-substituted, molecular sieves permit only end-on approach of linear alkanes to the active centers, thereby favoring enhanced reactivity of the terminal methyl groups. By optimizing cage dimension, with respect to that of the hydrocarbon reactant, as well as adjusting the average separation of active centers within a cage, and by choosing the sieve with the appropriate pore aperture, highly selective conversions such as n-hexane to hexanoic acid or adipic acid, and cyclohexane to cyclohexanol, cyclohexanone, or adipic acid, may be effected...
275 citations
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TL;DR: In this article, the gas phase reactions of O 3 with a series of alkenes have been investigated at 296±2 K and atmospheric pressure of air in the presence of cyclohexane at concentrations sufficient to scavenge any OH radicals formed.
Abstract: The gas-phase reactions of O 3 with a series of alkenes have been investigated at 296±2 K and atmospheric pressure of air in the presence of cyclohexane at concentrations sufficient to scavenge any OH radicals formed. The expected products of the OH radical-initiated reaction of cyclohexane, cyclohexanone and cyclohexanol, were observed in all cases. From a knowledge of the chemistry of cyclohexane in these reaction systems and the cyclohexanone and cyclohexanol formation yields obtained, the following formation yields of OH radicals in these O 3 -alkene reactions were derived: propene, 0.33; 1-butene, 0.41; 2-methylpropene, 0.84; cis-2-butene, 0.41; trans-2-butene, 0.64; 2-methyl-1-butene, 0.83; 2-methyl-2-butene, 0.89; 2,3-dimethyl-2-butene, 1.00; cyclohexene, 0.68; 1,3-butadiene, 0.08; all with estimated overall uncertainties of a factor of ∼1.5
266 citations
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TL;DR: The rate-determining step in catalysis was shown to be the release of NADP from the oxidized enzyme, which is consistent with a Baeyer-Villiger rearrangement mechanism for the enzymatic oxygenation of cyclohexanone.
Abstract: Cyclohexanone monooxygenase (CHMO), a bacterial flavoenzyme, carries out an oxygen insertion reaction on cyclohexanone to form a seven-membered cyclic product, e-caprolactone. The reaction catalyzed involves the four-electron reduction of O2 at the expense of a two-electron oxidation of NADPH and a two-electron oxidation of cyclohexanone to form e-caprolactone. Previous studies suggested the participation of either a flavin C4a-hydroperoxide or a flavin C4a-peroxide intermediate during the enzymatic catalysis [Ryerson, C. C., Ballou, D. P., and Walsh, C. (1982) Biochemistry 21, 2644−2655]. However, there was no kinetic or spectral evidence to distinguish between these two possibilities. In the present work we used double-mixing stopped-flow techniques to show that the C4a-flavin−oxygen adduct, which is formed rapidly from the reaction of oxygen with reduced enzyme in the presence of NADP, can exist in two states. When the reaction is carried out at pH 7.2, the first intermediate is a flavin C4a-peroxide w...
245 citations
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TL;DR: In this article, N-doped ordered mesoporous carbons were used as supports to immobilize small-sized Pd nanoparticles (PdNPs), which provided a unique platform to investigate the influence of metal nanoparticle size, mesostructural properties, and N-functionalized supports on the selective hydrogenation of phenol to cyclohexanone, an important intermediate in the production of nylon 6 and nylon 66 in the chemical industry.
Abstract: N-functionalized ordered mesoporous carbons could be readily obtained by post-synthesis treatment with nitrogen containing molecules to achieve materials with a nitrogen loading as high as 8.6 wt % and well preserved mesopore structure. Using NH3 as nitrogen source dramatically increased the Brunauer–Emmett–Teller (BET) surface area and pore volume of the resultant hybrid material; however, N-doping with melamine as a source resulted in the contrary results. The N-doped carbons were used as supports to immobilize small-sized Pd nanoparticles (PdNPs), which provided a unique platform to investigate the influence of metal nanoparticle size, mesostructural properties, and N-functionalized supports on the selective hydrogenation of phenol to cyclohexanone, an important intermediate in the production of nylon 6 and nylon 66 in the chemical industry. The catalyst with ultrasmall (about 1.2 nm) PdNPs gave the best reaction activity and selectivity under mild conditions. In addition, the present multifunctional c...
243 citations