3282-54-0Relevant academic research and scientific papers
Selective dimerization of cyclohexene over a Re2O7-B2O3/Al2O3 catalyst under mild conditions
Greish, Alexander A.,Barkova, Alexandra P.,Finashina, Elena D.,Salmi, Tapio O.,Kustov, Leonid M.
, (2021)
A Re2O7-B2O3/Al2O3 catalyst was demonstrated to reveal significant activity in cyclohexene dimerization into 1-cyclohexenylcyclohexane with a total yield of 95 % and a selectivity close to
Kinetic study of the hydrodenitrogenation of carbazole over bulk molybdenum carbide
Szymanska, Agnieszka,Lewandowski, Marek,Sayag, Celine,Djega-Mariadassou, Gerald
, p. 24 - 31 (2003)
Hydrodenitrogenation (HDN) of N-containing compounds (carbazole in this paper) in the presence of a small amount of sulfur (50 ppm) requires a strong catalytic hydrogenating function. Bulk molybdenum carbide, Mo2C, behaves like a noble metal and has strong hydrogenating properties and can catalyse deep HDN if the S content is not too high. A kinetic investigation monitored both the hydrogenating function through carbazole consumption and the HDN of carbazole through two kinetically coupled cycles. Biphenyl was not observed. Kinetic coupling occurs by means of adsorbed orthocyclohexylaniline. The first route is the direct HDN reaction, leading to cyclohexylbenzene, while the second hydrogenation route leads to bicyclohexyl. At 633 K, a zero-order reaction is observed with respect to carbazole; total HDN is observed for 0.4 s, and the selectivity ratio of bicyclohexyl to cyclohexylbenzene is equal to 9.
Triphosgene and DMAP as Mild Reagents for Chemoselective Dehydration of Tertiary Alcohols
Ganiu, Moshood O.,Cleveland, Alexander H.,Paul, Jarrod L.,Kartika, Rendy
supporting information, p. 5611 - 5615 (2019/08/01)
The utility of triphosgene and DMAP as mild reagents for chemoselective dehydration of tertiary alcohols is reported. Performed in dichloromethane at room temperature, this reaction is readily tolerated by a broad scope of substrates, yielding alkenes preferentially with the (E)-geometry. While formation of the Hofmann products is generally favored, a dramatic change in alkene selectivity toward the Zaitzev products is observed when the reaction is carried out in dichloroethane at reflux.
Promising Ni/Al-SBA-15 catalysts for hydrodeoxygenation of dibenzofuran into fuel grade hydrocarbons: Synergetic effect of Ni and Al-SBA-15 support
Gbadamasi, Sharafadeen,Ali, Tammar Hussein,Voon, Lee Hwei,Atta, Abdulazeez Yusuf,Sudarsanam, Putla,Bhargava, Suresh K.,Abd Hamid, Sharifah Bee
, p. 25992 - 26002 (2016/03/25)
This work has been undertaken with the aim of designing promising noble-metal-free catalysts for efficient hydrodeoxygenation (HDO) of dibenzofuran (DBF) into fuel grade hydrocarbons. For this, various Ni/Al-SBA-15 catalysts with different Si/Al (50, 60, 70 and 80) mole ratios were synthesized and their catalytic performance was tested for HDO of DBF in a batch reactor. The catalysts were systematically characterized using XRD, N2-adsorption-desorption, Raman, H2-TPR, NH3-TPD, XRF, and FESEM techniques. The activity results showed that the HDO of DBF proceeds via hydrogenation of benzene on the Ni sites followed by cleavage of C-O bonds on the acidic sites of the catalyst to yield unsaturated hydrocarbons. Further hydrogenation of unsaturated hydrocarbons on the Ni sites gives bicyclohexane as the major product. Remarkably, a 100% DBF conversion was found for all the catalysts except for Ni/SBA-15 and Ni/Al-SBA-15(80) (Si/Al mole ratio = 80) catalysts, which showed 97.97 and 99.31%, respectively. A significant observation noticed in this study is that the incorporation of Al into Ni/SBA-15 results in an outstanding improvement in the selectivity of the bicyclohexane product. Among the catalysts tested, the Ni/Al-SBA-15(50) (Si/Al mole ratio = 50) catalyst showed the highest efficiency, with superior selectivity of ～87% for bicyclohexane and ～96% degree of deoxygenation at 10 MPa, 260 °C and 5 h. The obtained structure-activity results reveal the synergetic effect of Ni and support in HDO of DBF reaction: the concentration of acidic sites has a significant effect on the selectivity of the desired products.
Effective hydrodeoxygenation of dibenzofuran by a bimetallic catalyst in water
Dong, Peng,Lu, Guo-Ping,Cai, Chun
, p. 1605 - 1609 (2016/02/19)
Effective hydrodeoxygenation (HDO) of dibenzofuran (DBF) catalyzed by a bimetallic nickel/platinum (Ni/Pt) catalyst in water was demonstrated at 200 °C and 1.2 MPa hydrogen (H2) pressure. The bimetallic catalysts prepared by a wet chemical method exhibit prominent activity that overcomes the limitations of use of a single Ni or Pt metal catalyst. The yield of HDO products can be up to 90%. Reaction results indicate that the conversion of DBF was affected by the reaction temperature and H2 pressure. The deoxygenation selectivity was strongly dependent on reaction temperature. The reaction pathway is also proposed.
Following solid-acid-catalyzed reactions by MAS NMR spectroscopy in liquid phase - Zeolite-catalyzed conversion of cyclohexanol in water
Vjunov, Aleksei,Hu, Mary Y.,Feng, Ju,Camaioni, Donald M.,Mei, Donghai,Hu, Jian Z.,Zhao, Chen,Lercher, Johannes A.
supporting information, p. 479 - 482 (2014/01/23)
A microautoclave magic angle spinning NMR rotor is developed enabling insitu monitoring of solid-liquid-gas reactions at high temperatures and pressures. It is used in a kinetic and mechanistic study of the reactions of cyclohexanol on zeolite HBEA in 130 °C water. The 13Cspectra show that dehydration of 1-13C-cyclohexanol occurs with significant migration of the hydroxy group in cyclohexanol and the double bond in cyclohexene with respect to the 13C label. A simplified kinetic model shows the E1-type elimination fully accounts for the initial rates of 1- 13C-cyclohexanol disappearance and the appearance of the differently labeled products, thus suggesting that the cyclohexyl cation undergoes a 1,2-hydride shift competitive with rehydration and deprotonation. Concurrent with the dehydration, trace amounts of dicyclohexyl ether are observed, and in approaching equilibrium, a secondary product, cyclohexyl-1-cyclohexene is formed. Compared to phosphoric acid, HBEA is shown to be a more active catalyst exhibiting a dehydration rate that is 100-fold faster per proton. Hot analysis: The catalytic conversion of cyclohexanol on zeolite HBEA in hot liquid water leads to dehydration as well as alkylation products. A novel microautoclave suitable for application in magic angle spinning (MAS) NMR at high temperatures has been successfully applied to obtain new insight into the mechanistic pathway leading to an understanding of the reactions under selected experimental conditions.
Fluorinated metal oxide-assisted oligomerization of olefins
Lermontov, Sergey A.,Malkova, Alena N.,Yurkova, Lyudmila L.,Ivanov, Vladimir K.,Baranchikov, Alexander E.,Vasilyeva, Larisa P.
, p. 110 - 112 (2013/05/21)
Fluorinated alumina is an efficient catalyst for hex-1-ene, cyclohexene and isobutene oligomerization, whereas fluorinated titania and zirconia are inactive.
Selective dimerization of higher cycloolefins in the presence of micro- and micromesoporous zeolite catalysts
Grigor'Eva,Bubennov,Khazipova,Khalilov,Kutepov
, p. 444 - 449 (2014/01/17)
Selective synthesis of dimers of cycloolefins C6-C8 was carried out in the presence of highly dispersed zeolite catalysts HY, HBeta, and HZSM-12 and granulated zeolite HY-WB, which differ in acidic properties and pore structure. The high selectivity of microporous zeolite HZSM-12 in cyclohexene dimerization (100%) and micromesoporous zeolite HY-WB in cycloheptene and cyclooctene dimerization (90-95%) was established.
Comparison of the catalytic activity of [(η5-C 5H5)Ru(2,2′-bipyridine)(L)]OTf versus [(η5-C5H5)Ru(6,6′-diamino-2,2′- bipyridine)(L)]OTf (L = labile ligand) in the hydrogenation of cyclohexanone. Evidence for the presence of a metal-ligand bifunctional mechanism under acidic conditions
Dimondo, Domenico,Thibault, Michelle E.,Britten, James,Schlaf, Marcel
, p. 6541 - 6554 (2013/12/04)
The two title complexes as well as the dimeric complex [Ru(II) (η5-C5H5)(6,6′-diamino-2,2′- bipyridine)]2(OTf)2 have been synthesized and characterized by NMR and single-crystal X-ray crystallography. The direct structural comparison of the 2,2′-bipyridine and 6,6′-diamino-2, 2′-bipyridine complexes suggests that the electronic and steric environments of the ruthenium centers in both complexes are essentially equivalent, providing for a unique opportunity to probe the influence of the noncoordinated amine substituent on the relative reactivity and catalytic activity of the complexes. Opposite to what would be anticipated on the basis of steric effects, the bulkier amine-substituted ligand results in a catalyst showing substantially higher activity in the hydrogenation of cyclohexanone in acidic medium, which is attributed to the operation of a metal-ligand bifunctional hydrogenation mechanism mediated by the amine substituents in their protonated form acting as proton shuttles.
Sulfated SnO2 as a high-performance catalyst for alkene oligomerization
Yurkova, L. L.,Lermontov, S. A.,Kazachenko, V. P.,Ivanov, V. K.,Lermontov, A. S.,Baranchikov, A. E.,Vasil'Eva, L. P.
, p. 1012 - 1019,8 (2012/12/11)
Nanoparticulate (3-5 nm) sulfated tin dioxide shows high catalytic activity for the oligomerization of isobutylene, hexene-1, and cyclohexene. The acidity (Hammett acidity function H0) of sulfated stannia reaches H 0 = -16.04. We have studied the effect of synthesis conditions on the physicochemical and functional properties of sulfated SnO2.
