- Shape-selective Synthesis of 2,6-Diisopropylnaphthalene over H-Mordenite Catalyst
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2,6-Diisopropylnaphthalene is selectively produced in the liquid phase alkylation of naphthalene with propene or propan-2-ol over H-mordenite catalyst.
- Katayama, Atsuhiko,Toba, Makoto,Takeuchi, Genki,Mizukami, Fujio,Niwa, Shu-ichi,Mitamura, Shuichi
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- The isopropylation of naphthalene over USY zeolite with FAU topology. The selectivities of the products
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The isopropylation of naphthalene (NP) over USY zeolite (FAU06, SiO2/Al2O3 = 6) gave all eight possible diisopropylnaphthalene (DIPN) isomers: β,β- (2,6- and 2,7-), α,β- (1,3-, 1,6-, and 1,7-), and α,α- (1,4- and 1,5-). Th
- Sugi, Yoshihiro,Joseph, Stalin,Ramadass, Kavitha,Indirathankam, Sathish Clastinrusselraj,Premkumar, Selvarajan,Dasireddy, Venkata D.B.C.,Yang, Jae-Hun,Al-Muhtaseb, Alaa H.,Liu, Qing,Kubota, Yoshihiro,Komura, Kenichi,Vinu, Ajayan
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p. 606 - 615
(2021/03/31)
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- C-C Bond-Forming and Bond-Breaking Processes from the Reaction of Diesters with Me3SnLi. Synthesis of Complex Bridged Polycycles and Dialkyl Aromatic Compounds
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1,2-Aromatic diesters can be transformed into strained bridged polycyclic structures by a two-step procedure consisting of an initial reductive alkylation promoted by alkaline metals, followed by a reaction of the resulting unsaturated diesters with Me3SnLi. We propose that a stanna-Brook rearrangement plays a fundamental role in the formation of the polycyclic organotin acetals obtained. These unusual compounds could be further functionalized by tin-lithium exchange followed by alkylation of the newly formed tertiary carbanion. Alternatively, dialkylated aromatic hydrocarbons have been prepared via a decarbonilation reaction promoted by Me3SnLi. 1,4-Aromatic diesters were reductively dialkylated and then transformed into norbornadienone derivatives by reaction with Me3SnLi. Several stable dibenzonorbornadienones 41 have been prepared in just two steps starting from anthracene 38. The corresponding naphthalene analogues gave 1,4-dialkylnaphthalenes. The synthetic protocols described provide access to structures that are not easily obtained through existing synthetic methodologies.
- Martínez-García, Lucas,Lobato, Rubén,Prado, Gustavo,Monje, Pablo,Sardina, F. Javier,Paleo, M. Rita
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p. 1887 - 1897
(2019/02/14)
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- Isopropylation of naphthalene by isopropanol over conventional and Zn- and Fe-modified USY zeolites
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Catalytic performances of USY, MOR, and BEA zeolites were compared for the isopropylation of naphthalene by isopropyl alcohol in a high-pressure, fixed-bed reactor. The USY catalyst showed a high conversion of 86% and good stability but a low 2,6-/2,7-DIPN shape selectivity ratio of 0.94. In contrast, over the MOR catalyst, 2,6-DIPN was selectively synthesized with a high 2,6-/2,7-DIPN ratio of 1.75, but low naphthalene conversions and fast deactivation of the catalyst were observed. The USY catalyst was modified by Zn and Fe using the wet impregnation method to enhance the selectivity for 2,6-DIPN. The highest conversion (~95%) and selectivity for 2,6-DIPN (~20%) were achieved with 4% Zn/USY catalyst. It appeared that small metal oxide islands formed in the USY pores to decrease the effective pore size and thus render it mildly shape-selective. Zn loading also decreased the number of strong acid sites responsible for coke formation and increased the number of weak acid sites. The high conversion and stability of Zn-modified catalysts were ascribed to the presence of a suitable admixture of weak and strong acid sites with less coke deposition. The Fe-modified USY catalysts were less effective because the modification increased the number of the strong acid sites.
- Banu, Marimuthu,Lee, Young Hye,Magesh, Ganesan,Lee, Jae Sung
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p. 120 - 128
(2014/01/06)
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- Shape-selective synthesis of 2,6-diisopropylnaphthalene on H-mordenite catalysts
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To finally dispel any doubts on the shape-selective formation of 2,6-diisopropylnaphthalene (2,6-DIPN) over H-MOR zeolites, naphthalene alkylation was carried out over high-silica H-MOR catalysts with propylene or isopropanol as an alkylating agent and with or without cyclohexane as a solvent. Isomeric composition of DIPN's, determined by one-dimensional GC analysis, was additionally confirmed with advanced two-dimensional GC × GC. Our results proved beyond any doubt shape-selective formation of 2,6-DIPN over these H-MOR catalysts from naphthalene and propylene and without cyclohexane as a solvent. The DIPN mixture contained 60-64% 2,6-DIPN, and the ratio of 2,6-DIPN/2,7-DIPN was in the range 2.5-2.8. We also showed that shape-selective formation of 2,6-DIPN over H-MOR catalyst was depressed by using isopropanol instead of propylene and in the presence of cyclohexane.
- Brzozowski, Robert,Buijs, Wim
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experimental part
p. 181 - 187
(2012/10/07)
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- Shape-selective diisopropylation of naphthalene in H-Mordenite: Myth or reality?
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Selective diisopropylation of naphthalene to 2,6-diisopropylnaphthalene is a challenging goal in sustainable catalysis. Ultrastable Y and H-Mordenite zeolites are the best catalysts reported in the literature with respect to 2,6-diisopropylnaphthalene selectivity. It is generally accepted that in the case of H-Mordenite, shape-selectivity is responsible for the observed 2,6-diisopropylnaphthalene selectivity, while on Ultrastable Y-zeolite, the observed selectivity reflects the internal thermodynamic equilibrium of positional isomers. Revisiting both the experimental and the computational work in this field now leads to the conclusion that shape-selectivity of whatever kind can be ruled out in the case of H-Mordenite. H-Mordenite catalysts produce usually a kinetically controlled mixture of diisopropylnaphthalene isomers which can shift to the direction of a thermodynamical distribution at high reaction temperatures or over more active catalysts.
- Bouvier, Christophe,Buijs, Wim,Gascon, Jorge,Kapteijn, Freek,Gagea, Bogdan C.,Jacobs, Pierre A.,Martens, Johan A.
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scheme or table
p. 60 - 66
(2010/06/19)
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- Regioselective arene functionalization: Simple substitution of carboxylate by alkyl groups
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Arenes with various alkyl side-chains were synthesized in high yields and excellent regioselectivities. Starting from toluic and naphthoic acids, the carboxylate group was conveniently substituted by alkyl halides by Birch reduction and subsequent decarbonylation. The method is characterized by inexpensive starting materials and reagents, and methylation of arenes was realized. Besides simple alkyl substituents, the scope of arene functionalization was extended by benzyl, fluoro, amino, and ester groups. We were able to control the alkylation of 1-naphthoic acid during Birch reduction by the addition of tert-butanol. This allowed the regioselective synthesis of mono and bis-substituted naphthalenes from the same starting material.
- Krueger, Tobias,Vorndran, Katja,Linker, Torsten
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experimental part
p. 12082 - 12091
(2010/05/17)
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- The alkylation of naphthalene over one-dimensional fourteen-membered ring zeolites. the influence of zeolite structure and alkylating agent on the selectivity for dialkylnaphthalenes
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The alkylation, i.e., isopropylation, s-butylation, and t-butylation, of naphthalene (NP) was examined over one-dimensional fourteen-membered (14-MR) zeolites: CIT-5 (CF1), UTD-1 (DON), and SSZ-53 (SFH), and compared to the results over H-mordenite (MOR)
- Sugi, Yoshihiro,Maekawa, Hiroyoshi,Naiki, Hiroaki,Komura, Kenichi,Kubota, Yoshihiro
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experimental part
p. 1166 - 1174
(2009/05/06)
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- Zeolite pore entrance effect on shape selectivity in naphthalene isopropylation
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Naphthalene alkylation with propylene was studied over various large-pore zeolites and also over amorphous aluminosilicate catalysts. Isomeric distribution of isopropylnaphthalenes (IPN) and diisopropylnaphthalenes (DIPN) were compared at different temperatures. The shape-selectivity effect that occurred in the entrances to the pores could be responsible for high α-selectivity in monoisopropylation and 1NR-selectivity in diisopropylation observed in the naphthalene alkylation over wide pore zeolites. The product was then relatively rich in 1-IPN, 1,3-DIPN, and 1,4-DIPN. This type of shape selectivity suppressed other shape-selectivity effects, e.g., high β-selectivity of reactions occurring inside channels or cavities of the zeolite. High concentration of TIPN in alkylation products could be explained superbly with the help of catalysis in pore entrances. The explanation of such results was proposed to be a specific shape-selectivity effect of alkylation reaction occurring in the entrances to the pores of zeolite.
- Brzozowski,Skupinski
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p. 313 - 318
(2007/10/03)
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