ChemInform Abstract: Catalytic Oxidation of Alcohols: Recent Advances

Abstract

Review: 330 refs.

First-Row-Transition Ion Metals(II)-EDTA Functionalized Magnetic Nanoparticles as Catalysts for Solvent-Free Microwave-Induced Oxidation of Alcohols

“…With the growing concern to bring out a more environmentally friendly chemical process, the use of a solvent-free synthetic protocol is of great significance. In addition, the heating mode through MW irradiation that requires low power and possibility to enhance the activity of alcohol oxidation reactions [6,7,14,[34][35][36][37][38][39][40][41] is a feature to take into account. In order to find the optimized reaction conditions, 1-phenylethanol was selected as a model alcohol substrate to oxidize (Scheme 1).…”

“…In general, the activity was enhanced upon increasing the temperature up to 110 • C. For 5 MNPs full conversion (99% yield of acetophenone) is reached at 6 h and 110 • C, in comparison with 77% (80 • C) and 79.2% (140 • C) yields obtained at the same reaction time. The second and third most active catalytic systems at 110 • C were 1 and 3 MNPs, which produce acetophenone in a yield of 95% and 85%, respectively, after 6 h. Screening at the highest temperature, 140 • C, resulted in a slightly increase of activity till 1 h reaction time, whereafter the corresponding yield of acetophenone was lower than at 110 • C and even lower than at 80 • C after 15 h. The increase in activity with temperature is expected on kinetic basis and can enhance the formation of radical species (t-BuOO· and t-BuO) that will further interact with the alcohol substrate and promote the oxidation reaction [6,7,41]. However, at 140 • C, overoxidation and/or decomposition of the oxidant can result in a lower yield of acetophenone.…”

“…85%, respectively, after 6 h. Screening at the highest temperature, 140 °C, resulted in a slightly increase of activity till 1 h reaction time, whereafter the corresponding yield of acetophenone was lower than at 110 °C and even lower than at 80 °C after 15 h. The increase in activity with temperature is expected on kinetic basis and can enhance the formation of radical species (t-BuOO•and t-BuO) that will further interact with the alcohol substrate and promote the oxidation reaction [6,7,41]. However, at 140 °C, overoxidation and/or decomposition of the oxidant can result in a lower yield of acetophenone.…”

“…Nowadays it is imperative to convert alcohol substrates into the desired more oxidized forms, to fulfill the demand of the market, in a sustainable manner. The oxidative chemical process should not generate large amounts of waste materials or use hazardous oxidizing agents and should occur in a catalytic-mediated system [4][5][6][7]. Hence, it is also highly desirable to develop cheap catalysts.…”

Solvent-Free Microwave-Induced Oxidation of Alcohols Catalyzed by Ferrite Magnetic Nanoparticles

“…In order to improve this type of catalytic system, a valid approach is to turn it into a microwave (MW)-induced catalytic oxidation process, which is about a promising technology for a high activity, especially coupled with appropriate MW absorbent catalysts [31][32][33]. MW irradiation can provide a much more efficient synthetic protocol than conventional heating towards the production of an added value product, since that similar yields can be obtained in a shorter time and/or the selectivity can be improved [33][34][35][36][37][38][39][40].…”