A Catalytic Oxidative Esterification of Aldehydes Using V₂O₅−H₂O₂

Abstract

[reaction: see text] Aldehydes, in the presence of methanol, undergo oxidative transformation to the corresponding esters upon treatment with catalytic amounts of vanadium pentoxide in combination with oxidant hydrogen peroxide. Mild reaction conditions, shorter reaction times, high efficiencies, cost-effectiveness, and facile isolation of the desired products make the present methodology a practical alternative.

Attempted [2]Catenane Synthesis via a Quasi[1]catenane by a Templated Backfolding Strategy

“…[14] Furtheroxidationtothe esters with V 2 O 5 and hydrogen peroxide in acidic ethanol yielded the terephthalic ester in 69 % yield. [15] Because some monocarboxylic acid was still present due to hydrolysis this yield may be improved. Fortunately, the subsequent radical bromination went cleanly, giving dibromide 22 in 66 % yield after recrystallization.…”

The Effect of Indium(III) Triflate in Oxone-Mediated Oxidative Methyl Esterification of Aldehydes

“…Although a couple of the esterifying transformations of aldehydes using metal-based reagents have been reported, including iridium, [3][4][5] rhenium, 6) ruthenium, 7) rhodium, 8) palladium, 9,10) manganese, 11) iron, 12) copper, 13) tin, 14) and pyridinium dichromate (PDC), 15,16) those heavy/transition metal oxidants might not be sufficiently environmentally benign. As a consequence, esterification methodologies employing H 2 O 2 and catalytic amounts of metal-based reagents, such as titanosilicate, 17) vanadium pentoxide, 18,19) iron salt, and zinc salt, 20,21) have been introduced. However, in many cases, the reagents are limited by the use of H 2 O 2 with the combination of fourth-row transition elements.…”

Selective functionalization of n-hexane with molecular O2 catalyzed by immobilized Cu/Co, Cu/Fe and Co/V complexes on modified Al2O3

“…The oxidation of n-hexane appears to proceed mainly by a mechanism involving both C-and O-centred radicals since the formation of oxidized products clearly decreases [37] when the reaction (18.6% overall conversion, run 4, Table 2) with CuFeL 2 is carried out in the presence of a trap for carbon (such as trichlorobromomethane, CBrCl 3 ) or oxygen radicals (such as diphenylamine, Ph 2 NH) in stoichiometric amounts relative to the substrate (ca. 14.2 and 13.9% overall conversion, respectively).…”

“…Mechanistic considerations Alkane oxidation can proceed by three main mechanisms: oxidation via a free-radical chain process, oxidation through coordination of the substrate and catalytic oxygen transfer [37,38]. These are mainly dependent upon the reaction conditions.…”