Oxidovanadium complexes with tridentate aroylhydrazone as catalyst precursors for solvent-free microwave-assisted oxidation of alcohols

Abstract

a b s t r a c tAroylhydrazone oxidovanadium compounds, viz.

Copper(II) and Sodium(I) Complexes based on 3,7‐Diacetyl‐1,3,7‐triaza‐5‐phosphabicyclo[3.3.1]nonane‐5‐oxide: Synthesis, Characterization, and Catalytic Activity

“…Increasing the temperature to 80 8Cr esulted in an increase in the yield up to 41 %i n6h ( Table 5, entry 2), anda ne xtension of the reaction time, keeping this latter temperature, led to as ignificant improvement in the yield (78 %a fter 21 ha nd 89 %a fter 48 h: Ta ble 5, entries 3 and 4). In agreement with that already reported, [43][44][45][46] the presence of both ab ase (K 2 CO 3 )a nd TEMPO is crucial for the reaction to proceed ( Table 5, entries 5a nd 6).…”

“…[41,42] Several copper-and other transition-metal-based complexes that effectively catalyze this reactionu nder different conditions have been studied by our group. [43][44][45][46] Among the metalloenzymes that perform the oxidation of organic compounds by activating molecular dioxygen is catechol oxidase,at ype III metalloprotein that contains copper at the active center.S uch an enzyme has the ability to catalyze the oxidation of ortho-phenols to the appropriate ortho-quinones by molecular oxygen. [47][48][49] The catecholase activity of variousm ono-and dicopper compounds, as well as that of copperc lusters with differents tructural topologies, has been widely explored.…”

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

“…of t-BuOOH, 0.5 h of reaction time). This increasing activity behaviour along with the temperature rising was expected since temperature has influence in the formation of radical intermediates promoted by the organic peroxidative oxidant [32,[36][37][38]40,49,50]. At 120 • C t-BuOOH is more effectively consumed and no increased yield was observed at 150 • C due its self-decomposition at such a temperature.…”

“…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]. In addition, ferrites or materials composed of ferrite powder have attracted a great interest for their strong MW absorption ability, for instance they have been used as absorbing walls for radio waves [41] and for MW-induced degradation of environmental organic contaminants [42].…”

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).…”