Xn:Harmful;590-67-0Relevant articles and documents
Acid-Catalyzed Hydrolysis of Bridged Bi- and Tricyclic Compounds. 25. Comparison of the Hydrations of 2-Methyl-2-norbornene and 2-Methylenenorbornane with Those of 1-Methylcyclohexene and Methylenecyclohexane
Lajunen, Martti,Hiukka, Risto
, p. 1522 - 1525 (1986)
Hydration rates of 2-methyl-2-norbornene, 2-methylenenorbornane, 1-methylcyclohexene, and methylenecyclohexane were measured spectrophotometrically in aqueous perchloric acid.The activation parameters and solvent deuterium isotope effects are in all cases in agreement with the slow proton transfer to an olefinic carbon atom.The free energy diagrams show that the Gibbs energy of the transition state of protonation (hydration) is higher for methylenecycloalkanes than for methylcycloalkenes.The energy difference is small (0.8 kJ mol-1) in the case of the bicyclic olefins and large (11.5 kJ mol-1) in the case of the monocyclic olefins mentioned.Thus, no marked difference in the energies of the transition states caused by a possible distortion of the ?-orbitals of 2-methyl-2-norbornene can be seen in the hydrations of the bicyclic olefins.An explanation for the latter large difference is evidently a change of conformation during the protonation of 1-methylcyclohexene, which possibly also causes an exceptionally low isotope effect (kH/kD=1.13).
Hydrogen-atom and oxygen-atom transfer reactivities of iron(
Banerjee, Sridhar,Haukka, Matti,Hossain, Md. Kamal,Huelsmann, Ricardo Dagnoni,Martendal, Edmar,Munshi, Sandip,Nordlander, Ebbe,Paine, Tapan K.,Peralta, Rosely,Singh, Reena,Sinha, Arup,Valiati, Andrei Felipe,Wendt, Ola F.,Xavier, Fernando,Yiga, Solomon
supporting information, p. 870 - 884 (2022/02/01)
A series of iron(ii) complexes with the general formula [FeII(L2-Qn)(L)]n+ (n = 1, L = F?, Cl?; n = 2, L = NCMe, H2O) have been isolated and characterized. The X-ray crystallographic data reveals that
Deciphering Reactivity and Selectivity Patterns in Aliphatic C-H Bond Oxygenation of Cyclopentane and Cyclohexane Derivatives
Martin, Teo,Galeotti, Marco,Salamone, Michela,Liu, Fengjiao,Yu, Yanmin,Duan, Meng,Houk,Bietti, Massimo
supporting information, p. 9925 - 9937 (2021/06/30)
A kinetic, product, and computational study on the reactions of the cumyloxyl radical with monosubstituted cyclopentanes and cyclohexanes has been carried out. HAT rates, site-selectivities for C-H bond oxidation, and DFT computations provide quantitative information and theoretical models to explain the observed patterns. Cyclopentanes functionalize predominantly at C-1, and tertiary C-H bond activation barriers decrease on going from methyl- and tert-butylcyclopentane to phenylcyclopentane, in line with the computed C-H BDEs. With cyclohexanes, the relative importance of HAT from C-1 decreases on going from methyl- and phenylcyclohexane to ethyl-, isopropyl-, and tert-butylcyclohexane. Deactivation is also observed at C-2 with site-selectivity that progressively shifts to C-3 and C-4 with increasing substituent steric bulk. The site-selectivities observed in the corresponding oxidations promoted by ethyl(trifluoromethyl)dioxirane support this mechanistic picture. Comparison of these results with those obtained previously for C-H bond azidation and functionalizations promoted by the PINO radical of phenyl and tert-butylcyclohexane, together with new calculations, provides a mechanistic framework for understanding C-H bond functionalization of cycloalkanes. The nature of the HAT reagent, C-H bond strengths, and torsional effects are important determinants of site-selectivity, with the latter effects that play a major role in the reactions of oxygen-centered HAT reagents with monosubstituted cyclohexanes.
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.].
