612-75-9Relevant articles and documents
Hydrodesulfurization of 4,6-DMDBT in the high boiling fraction of gas oil
Choi, Ki-Hyouk,Korai, Yozo,Mochida, Isao
, p. 434 - 435 (2003)
A high boiling fraction of straight run gas oil, which contained 4,6-DMDBT by addition but free from dimethylbiphenyl and dimethylcyclohexylbenzene of its HDS products, was desulfurized over commercial catalysts to find principal products of 4,6-DMDBT. Thus, HDS of 4,6-DMDBT in the high boiling fraction of real feed was proved to proceed principally through hydrogenative route. During the HDS of the fraction, 4,6-DMDBT was found to be produced from trimethyldibenzothiophenes. This activity depended very much on the acidity of the catalyst.
Noble metal silicides catalysts with high stability for hydrodesulfurization of dibenzothiophenes
Yang, Kaixuan,Chen, Xiao,Bai, Zongxuan,Liang, Changhai
, p. 205 - 212 (2021)
Development of highly efficient and long stable hydrodesulfurization (HDS) catalysts still is a great challenge for the refining industry. In this work, a series of intermetallic noble metal silicides supported by carbon nanotubes catalysts (Pt2Si/CNTs, RhxSi/CNTs, and RuSi/CNTs) have been developed by chemical vapor deposition successfully, using dichlorodimethylsilane as Si source. These materials were used as efficient catalysts for the deep HDS of dibenzothiophenes (4,6-DMDBT and DBT) and performed high selectivity to the direct desulfurization pathway. The sequence of HDS activity over noble metal silicides catalysts is in keeping with the sequence of HDS activity of the corresponding metal catalysts, which is Pt2Si/CNTs > RhxSi/CNTs >> RuSi/CNTs. In addition, the Pt2Si/CNTs performed an excellent stability in 100 h stability testing for HDS of 4,6-DMDBT. Therefore, this sulfur-tolerant noble metal silicides could be as promising catalysts for the ultra-deep HDS of fossil-fuel.
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Bock,Moyer,Adams
, p. 2054,2056 (1930)
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PALLADIUM-CATALYZED CROSS-COUPLING OF DIARYLIODONIUM SALTS WITH ORGANOTIN COMPOUNDS
Bumagin, N. A.,Sukhomlinova, L. I.,Igushkina, S. O.,Banchikov, A. N.,Tolstaya, T. P.,Beletskaya, I. P.
, p. 2128 - 2129 (1992)
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Erker
, p. 189,198,199 (1977)
Activity of Mo(W)S2/SBA-15 Catalysts Synthesized from SiMoW Heteropoly Acids in 4,6-Dimethyldibenzothiophene Hydrodesulfurization
Koklyukhin,Nikul’shina,Sheldaisov-Meshcheryakov,Mozhaev,Lancelot,Blanchard,Lamonier,Nikul’shin
, p. 1293 - 1299 (2019)
Abstract: Mo(W)/SBA-15 catalysts are prepared using heteropoly acids H4SiMo12O40, H4SiW12O40, and H4SiMo3W9O40. The catalysts in the sulfide form are studied by low-temperature nitrogen adsorption, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Catalytic properties are tested in the hydrodesulfurization of 4,6-dimethyldibenzothiophene. It is shown that the gas-phase sulfiding of Mo(W)/SBA-15 catalysts leads to increase in the average length of particles and the number of Mo(W)S2 layers in active phase particles compared with liquid-phase sulfiding with the use of dimethyl sulfide. The replacement of a quarter of tungsten atoms with molybdenum ones makes it possible to considerably improve the catalytic activity of the mixed catalyst Mo + W/SBA-15 compared with the monometallic counterparts. This effect can be enhanced due to the use of mixed heteropoly acid H4SiMo3W9O40 as a precursor of the active phase of the MoW/SBA-15 catalyst, which is apparently associated with the formation of MoWS2 active sites.
Visible Light Induced Aerobic Coupling of Arylboronic Acids Promoted by Hydrazone
Xia, Hongyu,Wang, Ganghu,Zhao, Dongbo,Zhu, Chunyin
supporting information, p. 922 - 929 (2022/02/10)
A visible-light-induced oxidative coupling of arylboronic acids has been developed for the synthesis of biaryls. The reaction that employs polydentate hydrazones as the bifunctional catalyst works smoothly under room temperature. It is compatible with a w
Zirconium-redox-shuttled cross-electrophile coupling of aromatic and heteroaromatic halides
Fu, Yue,Liu, Fang-Jie,Liu, Peng,Tang, Jian-Tao,Toste, F. Dean,Wu, Ting-Feng,Ye, Baihua,Zhang, Yue-Jiao
supporting information, p. 1963 - 1974 (2021/07/07)
Transition metal-catalyzed cross-electrophile coupling (XEC) is a powerful tool for forging C(sp2)–C(sp2) bonds in biaryl molecules from abundant aromatic halides. While the synthesis of unsymmetrical biaryl compounds through multimetallic XEC is of high synthetic value, the selective XEC of two heteroaromatic halides remains elusive and challenging. Herein, we report a homogeneous XEC method, which relies on a zirconaaziridine complex as a shuttle for dual palladium-catalyzed processes. The zirconaaziridine-mediated palladium (ZAPd)-catalyzed reaction shows excellent compatibility with various functional groups and diverse heteroaromatic scaffolds. In accord with density functional theory (DFT) calculations, a redox transmetallation between the oxidative addition product and the zirconaaziridine is proposed as the crucial elementary step. Thus, cross-coupling selectivity using a single transition metal catalyst is controlled by the relative rate of oxidative addition of Pd(0) into the aromatic halide. Overall, the concept of a combined reducing and transmetallating agent offers opportunities for the development of transition metal reductive coupling catalysis.
Tandem Mn–I Exchange and Homocoupling Processes Mediated by a Synergistically Operative Lithium Manganate
Uzelac, Marina,Mastropierro, Pasquale,de Tullio, Marco,Borilovic, Ivana,Tarrés, Màrius,Kennedy, Alan R.,Aromí, Guillem,Hevia, Eva
supporting information, p. 3247 - 3253 (2020/12/11)
Pairing lithium and manganese(II) to form lithium manganate [Li2Mn(CH2SiMe3)4] enables the efficient direct Mn–I exchange of aryliodides, affording transient (aryl)lithium manganate intermediates which in turn undergo spontaneous C?C homocoupling at room temperature to furnish symmetrical (bis)aryls in good yields under mild reaction conditions. The combination of EPR with X-ray crystallographic studies has revealed the mixed Li/Mn constitution of the organometallic intermediates involved in these reactions, including the homocoupling step which had previously been thought to occur via a single-metal Mn aryl species. These studies show Li and Mn working together in a synergistic manner to facilitate both the Mn–I exchange and the C?C bond-forming steps. Both steps are carefully synchronized, with the concomitant generation of the alkyliodide ICH2SiMe3 during the Mn–I exchange being essential to the aryl homocoupling process, wherein it serves as an in situ generated oxidant.
