Oxidation of alcohols by molybdenum and tungsten peroxo complexes

Mononuclear and dinuclear peroxotungsten complexes with co-ordinated dipeptides as potent inhibitors of alkaline phosphatase activity

“…The result of the investigation is consistent with the proposal implicating formation of a monoperoxo-W (VI) intermediate, which is inactive in GSH oxidation and is in accord with the earlier suggestions that for a peroxotungsten complex to be active in oxidation an oxo-diperoxo configuration may be a prerequisite [6]. Significantly, during one of our previous studies involving redox activity of the complexes 1 and 2 in oxidative bromination, only two of the peroxo groups out of 4 peroxides present per molecule of the complex were found to be involved in bromide oxidation [26].…”

Transition Metal Peroxides. Synthesis and Role in Oxidation Reactions*Dedicated, on the occasion of his 80th birthday, to our ‘vitae ac studiorum magister in secunda et in adversa fortuna’ Emeritus Professor Giorgio Modena, Padova University, who showed us the way toward Chemistry.

“…This kind of reaction is usually observed with early transition metal ions having a d 0 configuration, namely Mo(VI), W(VI), Ti(IV) and Re(VII), and is performed under both homogeneous and heterogeneous conditions in the presence of H 2 O 2 (or ROOH) as primary oxidant 371 . Anionic W(VI) and Mo(VI) peroxo complexes, containing either H + 101 372 or a lipophilic cation 102 373,374 , have been employed as effective oxidants of primary and secondary alcohols to carbonyl compounds. Using stoichiometric amounts of 102 in nonpolar solvents, no competition with double-bond epoxidation or aldehyde over-oxidation is observed 374 377 .…”

Oxidoperoxidotungsten(VI) Complexes with Secondary Hydroxamic Acids: Synthesis, Structure and Catalytic Uses in Highly Efficient, Selective and Ecologically Benign Oxidation of Olefins, Alcohols, Sulfides and Amines with H2O2 as a Terminal Oxidant

“…Alcohol and sulfide oxidation with other oxido-or oxidoperoxidotungsten catalysts [24][25][26][27] was less efficient than our system in terms of yield and TON. In heteropolytungstate-catalyzed alcohol and amine oxidations, [28][29][30] the yield, TON and selectivity are much lower than our results.…”

“…Reports of metal complexes in the catalytic oxidation of alcohols [21] to aldehydes/ketones and carboxylic acids, sulfides to sulfoxides and sulfones, [22] and amines to nitro, nitroso-and hydroxylamines have appeared in the literature. [23] Jacobson et al, [24] along with many other authors, [25][26][27] reported homogeneous oxidation of alcohols to carbonyl compounds with various transition-metal complexes, including those of Mo and W, as catalysts that operated with moderate efficiency. Heteropolytungstate(VI) systems were also used [28][29][30] for the catalytic oxidation of alcohols, tertiary amines and sulfides.…”