The role of MoO2Cl2 and some complexes containing MoO2Cl2 as catalysts for various Lewis acid catalysed organic transformations, oxidation and reduction reactions is reviewed. © Indian Academy of Sciences.

Dillip Kumar Chand

Department Of Chemistry

Kandasamy Jeyakumar

catalysis

molybdenum oxide

Rate constants

Lewis acid

Organic transformations

Oxidation and reduction

Chlorine compounds

Fulltext

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Chemical Sciences

A surfactant based oxodiperoxo molybdenum complex, which could activate molecular oxygen, has been employed as a catalyst for controlled oxidation of benzylic alcohols to corresponding carbonyls. The oxidation reactions were carried out under aqueous environment, however, in the absence of any extraneous base or co-catalyst. Sensitive/oxidizable functional groups like cyano, sulfide, hydroxyl, aryl-hydroxyl, alkene (internal/terminal), alkyne (internal/terminal), and acetal were tolerated during the transformations. Such selectivity is attributed to the mild nature of the catalyst. The methodology could also be scaled-up for multi-gram synthesis and the protocol is likely to find practical use since it requires an inexpensive recyclable-catalyst and easily available oxidant (under green conditions). A plausible mechanism is proposed with the help of preliminary computational study. © 2019 Elsevier Inc.

Journal of Catalysis

A molybdenum based metallomicellar catalyst for controlled and chemoselective oxidation of activated alcohols in aqueous medium

A surfactant based molybdenum system that exhibits catalytic activity for sulfoxidation reactions of various organic sulfides in aqueous medium has been developed and comprehensively characterized using IR, XRD, NMR, ESI-MS, DLS and TEM. The catalyst showcases remarkable selectivity for the preparation of both sulfoxides and sulfones in the range of good to excellent yields. Furthermore, the catalyst showed a high degree of tolerance towards various sensitive functional groups such as hydroxyl, acetal, aldehyde, amine, imine, oxime, cyano and alkene. © the Partner Organisations 2014.

Green Chemistry

A molybdenum based metallomicellar catalyst for controlled and selective sulfoxidation reactions in aqueous medium

Oxo-molybdenum chemistry is of great interest since such units are found in the active sites of a majority of molybdo-enzymes. In order to mimic the biological systems, a number of oxo-molybdenum complexes have been synthesised and studied. This review describes synthesis, structure and applications of oxomolybdenum complexes particularly cis-MoO2(L)(D) where L stands for a dianionic tridentate ONO ligand and D for a donor solvent molecule/monodentate ligand. The ligand moieties are derived from Schiff base, hydrazide Schiff base and other related tridentate ligands L(H)2. The coordination geometry around the Mo center in these complexes can be best described as a distorted octahedron in which the ONO-tridentate ligand occupies meridional position with two anionic oxygen donors mutually trans and are cis to the oxygen centers of the cis-dioxo group. Mostly the applications of cis-MoO2-(ONO) type complexes seen in literature are oxo transfer reactions like epoxidation, sulfoxidation and phosphine oxidation reactions. © Indian Academy of Sciences.

Synthesis, structure and applications of [cis-dioxomolybdenum(VI)-(ONO)] type complexes

Six new cis-dioxomolybdenum(VI) complexes of chiral Schiff-base ligands, derived from condensation of various amino alcohols and substituted salicylaldehydes, have been prepared and characterized by NMR, IR, ESI-MS and single crystal X-ray diffraction techniques. The geometry around the molybdenum center is distorted octahedral in which a tridentate Schiff-base ligand with two anionic oxygens and one neutral imine nitrogen occupies meridional position. The octahedral geometry of the cis-dioxomolybdenum center is additionally completed by a coordinated labile solvent molecule. In some complexes the sixth site is found to be vacant where the relatively bulky substituents hinder the coordination of the solvent. These complexes are tested for catalytic enantioselective sulfoxidation reactions using hydrogen peroxide as oxidant at low temperature which shows high selectivity along with good to moderate enantiomeric excess. ESI-MS study of the reaction mixture indicates the formation of oxoperoxoMo(VI) complexes during catalysis. The steric effect originated from the substituent on chiral ligand on the catalytic reaction is also discussed. It is found that the substituents at the β position of the amino alcohol seem to greatly influence the enantioselectivity of the oxidation reactions. © 2011 Elsevier B.V. All rights reserved.

Inorganica Chimica Acta

New chiral molybdenum complex catalyzed sulfide oxidation with hydrogen peroxide

A simple and efficient method for the oxidation of sulfides to sulfones at room temperature using ammonium heptamolybdate and 30% H2O2 is developed. The reactions provide excellent yields within short time, also sensitive functional groups such as allyl, vinyl, propargyl, alcohol, ketone, ester, pyridine and nitrile are found to be tolerated. © 2009 Elsevier B.V. All rights reserved.

Catalysis Communications

Simple and efficient method for the oxidation of sulfides to sulfones using hydrogen peroxide and a Mo(VI) based catalyst

Selective oxidation of sulfides to sulfoxides and sulfones is achieved by H2O2 using MoO2Cl2 as the catalyst. Various substituted sulfides having functional groups such as methyl, methoxy, bromo, nitro, alkene, alkyne, alcohol, ester, aldehyde and remarkably an oxime are successfully and selectively oxidized without affecting the sensitive functionalities. © 2006 Elsevier Ltd. All rights reserved.

Tetrahedron Letters

Selective oxidation of sulfides to sulfoxides and sulfones at room temperature using H2O2 and a Mo(VI) salt as catalyst

Selective and controlled aerobic oxidation of activated benzyl alcohols to the corresponding aldehydes is achieved in refluxing CH3CN using catalytic amounts of MoO2Cl2(L)2 where L is DMSO, DMF or THF. The catalysis reactions are possible under open air in the absence of any other external co-oxidants. However, bubbling of oxygen to the reaction mixture is useful in making the catalysis reaction sustained. Both activated and deactivated varieties of α-substituted benzyl alcohols (secondary alcohols) give ketones in the same reaction conditions. The inexpensive catalyst is selective towards activated primary benzyl alcohols and also, being mild, stops the oxidation at the aldehyde stage, making it synthetically useful. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Applied Organometallic Chemistry

Aerobic oxidation of benzyl alcohols by MoVI compounds

Журнал прикладной химии

ДИЭЛЕКТРИЧЕСКАЯ СПЕКТРОСКОПИЯ РАСТИТЕЛЬНЫХ МАСЕЛ

Molybdenum pentachloride (MoCl5) or molybdenum dichloride dioxide (MoO2Cl2): advanced catalysts for thioacetalization of heterocyclic, aromatic and aliphatic compounds

Journal	Data powered by TypesetJournal of Chemical Sciences
Publisher	Data powered by TypesetSpringer India
ISSN	09743626
Open Access	Yes