1728-46-7Relevant articles and documents
Solvent free ion exchange catalysis in the oxidation of organic compounds with sodium bromate
Shaabani, Ahmad,Lee, Donald G.
, p. 1255 - 1260 (2003)
The oxidation of organic compounds under solvent free ion exchange resin (IER) catalysis by sodium bromate has been studied at room temperature. Primary benzylic and secondary alcohols are converted to aldehydes and ketones and alkylarenes are oxidized to the corresponding α-ketones. The experimental procedure is simple and products are easily isolated in high yields at room temperature.
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.
Selective phenol hydrogenation under mild condition over Pd catalysts supported on Al2O3 and SiO2
Li, Xinzheng,Cheng, Ling,Wang, Xingyi
, p. 1249 - 1262 (2019/02/24)
Cyclohexanone (CHONE) is the key intermediate in the manufacture of nylon-6 and nylon-66. Selective hydrogenation of phenol into CHONE was investigated over Pd/SiO2 and Pd/Al2O3. The results show that the yield of CHONE reaches 98% or more over Pd/Al2O3 and Pd/SiO2 at 333?K under atmospheric pressure in cyclohexane solvent. High activity of Pd/Al2O3 is promoted by Lewis acidity, and phenol can be converted 100% within 300?min. The hydrogenation of CHONE occurs until the conversion of phenol approaches completion. Pd/SiO2 with smaller Pd nano-particles presents higher selectivity. For polar solvent, such as ethanol and dichloromethane, the activity of Pd catalysts decreases greatly. Auxiliary experiments verify that phenol adsorbs on Pd catalysts via the formation of π–c with an aromatic ring. Increased hydrogen pressure not only promotes significantly the rates of hydrogenation, but also increases the selectivity for CHONE, especially over Pd/SiO2-1 catalyst.
