6406-91-3Relevant articles and documents
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Aleksanyan et al.
, p. 264,265 (1965)
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Niobium(V) oxido tris-carbamate as easily available and robust catalytic precursor for the selective sulfide to sulfone oxidation
Bresciani, Giulio,Ciancaleoni, Gianluca,Crucianelli, Marcello,Gemmiti, Mario,Marchetti, Fabio,Pampaloni, Guido
, (2021/11/01)
The oxidation of the sulfide function promoted by a variety of vanadium compounds has been largely explored, whereas the use of homogeneous catalytic systems based on the heavier group 5 metals remains less explored. We report the use of easily available niobium and tantalum carbamates, i.e. [M(O2CNMe2)5] (M = Nb, 1; M = Ta, 2), [Nb(O2CNMe2)4], 3, [NbO(O2CNEt2)3], 4, and [NbCl3(O2CNEt2)2], 5, as effective catalysts for the conversion of a series of alkyl aryl and aromatic sulfides into the corresponding sulfones. NMR investigations on the performant niobium catalyst 4 unexpectedly revealed the substantial stability of this compound in the protic catalytic environment, and a plausible catalytic cycle was obtained by DFT studies. The two active catalytic species, i.e. 4 and its minor mono-methoxide derivative, presumably interconvert to each other exploiting the versatile coordination of the carbamato ligand.
A new phosphotungstate-supported rhenium carbonyl derivative: Synthesis, characterization and catalytic selective oxidation of thiophenes
Lu, Jingkun,Feng, Junwei,Ma, Xinyi,Wang, Ping,Xu, Baijie,He, Peipei,Jia, Jiage,Ma, Pengtao,Niu, Jingyang,Wang, Jingping
, p. 7322 - 7328 (2019/12/09)
A monomeric phosphotungstate-supported rhenium carbonyl derivative, [N(CH3)4]6H4[P2W17O62{Re(CO)3}2]·25H2O (1), has been synthesized in a conventional solution system and structurally characterized by single crystal X-ray diffraction crystallography, IR spectroscopy, thermogravimetric (TG) analyses, X-ray powder diffraction (XRPD), and electrospray ionization mass spectrometry (ESI-MS). To our knowledge, this is the first time that the {Re2} fragment existing in the polyoxoanion has been observed in polyoxometalate-supported metal carbonyl derivatives. Moreover, UV-vis spectroscopy was employed to elucidate the stability of the polyoxoanion, and its electrochemical properties were also investigated. In particular, complex 1 could act as an efficient homogeneous catalyst for selective oxidation of thiophenes. For example, dibenzothiophene (DBT) undergoes up to 99% conversion and 99% sulfone selectivity in acetonitrile with 30% H2O2 as an oxidant.
