22710-09-4Relevant articles and documents
Oxido-alcoholato/thiolato-molybdenum(VI) complexes with a dithiolene ligand generated by oxygen atom transfer to the molybdenum(IV) complexes
Sugimoto, Hideki,Sato, Masanori,Asano, Kaoru,Suzuki, Takeyuki,Ogura, Takashi,Itoh, Shinobu
, p. 42 - 48 (2018/10/20)
Oxido-alcoholato- and oxido-thiolato-molybdenum(VI) complexes bearing two ene-1,2-dithiolate ligands (cyclohexene-1,2-dithiolate) are prepared as synthetic models of molybdenum(VI) reaction centers of dimethyl sulfoxide reductase family of molybdenum enzymes. These complexes are prepared by oxygen atom transfer from tertiary amine N-oxide (trimethylamine N-oxide and N,N-dimethylaniline N-oxide) to the five-coordinate alcoholato- and thiolato-molybdenum(IV) complexes, and are characterized by UV–vis, cold-spray-ionization mass, resonance Raman, and 1H NMR spectroscopies. The oxygen atom transfer reactions are studied kinetically at a low temperature (?40 °C) to demonstrate that the reactivity of the thiolato-molybdenum(IV) complex is higher than that of alcoholato-molybdenum(IV) complex by about 7 times, and that the oxygen atom transfer reactivity increases with increasing the electron withdrawing ability of the p-substituent of N,N-dimethylaniline N-oxide derivatives. Mechanistic details are discussed based on the reactivity studies.
Renewable waste rice husk grafted oxo-vanadium catalyst for oxidation of tertiary amines to N-oxides
Panwar, Vineeta,Bansal, Ankushi,Ray, Siddharth S.,Jain, Suman L.
, p. 71550 - 71556 (2016/08/05)
Low cost renewable waste rice husks (RH) have been used as a support for grafting of an oxo-vanadium Schiff base via covalent attachment for the oxidation of tertiary amines to N-oxide. The synthesis of the desired RH grafted oxo-vanadium complex involves prior functionalization of the RH support with amino-propyltrimethoxysilane (APTMS) followed by its reaction with salicylaldehyde to get an RH-functionalized Schiff base which subsequently reacted with vanadyl sulphate to get the targeted oxo-vanadium catalyst. The synthesized catalyst was found to be an efficient heterogeneous catalyst and afforded an excellent yield of corresponding N-oxides via oxidation of tertiary amines with hydrogen peroxide as an oxidant. Furthermore, the synthesized catalyst was found to be quite stable and showed consistent activity for five runs without any loss in activity.
Oxovanadium(IV)-salen ion catalyzed H2O2 oxidation of tertiary amines to n-oxides- critical role of acetate ion as external axial ligand
Mathavan, Alagarsamy,Ramdass, Arumugam,Ramachandran, Mohanraj,Rajagopal, Seenivasan
supporting information, p. 315 - 326 (2015/04/14)
The oxovanadium(IV)-salen ion catalyzed H2O2 oxidation of N,N-dimethylaniline forms N-oxide as the product of the reaction. The reaction follows Michaelis-Menten kinetics and the rate of the reaction is accelerated by electron donating groups present in the substrate as well as in the salen ligand. This peculiar substituent effect is accounted for in terms of rate determining bond formation between peroxo bond of the oxidant and the N-atom of the substrate in the transition state. Trichloroacetic acid (TCA) shifts the λmax value of the oxidant to the red region and catalyzes reaction enormously. The cleavage of N￡O bond by vanadium complex leads to moderate yield of the product. But the percentage yield of the product becomes excellent in the presence of TCA.
