Recent advances in vanadium catalyzed oxygen transfer reactions

Abstract

Vanadium complexes have proven to be effective catalysts for the activation of peroxides and the selective oxidation of substrates like bromides, sulfides and alkenes. Besides their capability to form metalloperoxo species, which effectively transfer oxygen atoms to the substrate, these systems are synthetically useful for obtaining valuable oxidized molecules on a preparative scale, with a high degree of selectivity and TONs. Furthermore, the use of environmentally friendly oxidants like hydrogen and alkyl hydroperoxides increases significantly their potential application at an industrial level. Here we report a critical survey on the most effective homogeneous vanadium catalysts reported in the last decade concerning their synthetic application in oxygen transfer reactions (sulfoxidation, epoxidation, haloperoxidation) using hydrogen peroxide or alkyl hydroperoxides, demonstrating the different classes of ligands and complexes, their catalytic performances, their reactivity, chemo, stereo and substrate selectivity. Some examples of the use of non conventional reaction media or techniques and catalyst recycling studies will be also discussed

Vanadium haloperoxidases: From the discovery 30 years ago to X-ray crystallographic and V K-edge absorption spectroscopic studies

“…In view of the still increasing power of computational approaches such as the ADF Density Functional Theory package [145], it is also tempting to generate computational structures which can be validated/adjusted in both the EXAFS and XANES part of the X-ray absorption spectrum. and dioxidovanadium (V) stabilized by organic molecules [45,152]. However, recent studies [56] have shown that the influence of the protein stabilization of the active center goes beyond the first coordination sphere.…”

Salophen and salen oxo vanadium complexes as catalysts of sulfides oxidation with H2O2: Mechanistic insights

“…On the basis of economic and environmental reasons [2,3], oxidation processes with H 2 O 2 are sustainable processes: first of all H 2 O 2 is, besides dioxygen, the most appealing oxidant and the one with the highest "atom efficiency" (47% of active oxygen); in addition, aqueous hydrogen peroxide is readily accessible, safe to use and upon reduction only water is formed [4][5][6][7]. Catalytic systems based on different metals have been employed in conjunction with hydrogen peroxide for oxidation reactions [5].…”

Microwave‐Assisted Meyer–Schuster Rearrangement of Propargylic Alcohols Catalyzed by the Oxovanadate Complex [V(O)Cl(OEt)2]

“…In agreement with the well-known ability of oxo-vanadium(V) complexes to catalyze oxygen transfer reactions, [20] several orthovanadate derivatives of general composition [V(O)(OR)3] (R = alkyl, aryl or silanyl group) have proven to act as promoters of Meyer-Schuster-type rearrangements. [21] However, they usually operate under high temperature regimes (140-160 ºC) or in the presence of acidic co-catalysts, which limits seriously their synthetic applications.…”