1196-58-3Relevant academic research and scientific papers
Aromatic Substitution in the Gas Phase. Alkylation of Arenes by Gaseous C4H9+ Cations
Cacace, Fulvio,Ciranni, Giovanna,Giacomello, Pierluigi
, p. 1513 - 1516 (1981)
Butyl cations, obtained in the dilute gas state from the radiolysis of butane in the pressure range from 70 to 750 torr, have been allowed to react with benzene, toluene, and their mixtures or with trace amounts of o-xylene in the gaseous system.The gas-phase butylation yields invariably sec-butylarenes, remarkably free of isomeric byproducts, namely n- and tert-butylarenes.Other alkylation experiments, where gaseous butyl cations from the reaction of butane with radiolytically formed H3+ ions were used as reagent, confirmed the exclusive formation of sec-butylarenes.The butylation process displays the positional and substrate selectivity and the dependence of orientation on the pressure of the system, typical of other gas-phase ionic substitutions.At high pressures, ortho-para orientation predominates in the sec-butylation of toluene, with a ortho:meta:para ratio of 43:30:27 at 715 torr.As the pressure is reduced, a gradual shift in favor of the thermodynamically most stable meta-subsltituted arenium ion is observed, leading to a ortho:meta:para ratio of 31:48:21 at 70 torr.
Scandium(III) trifluoromethanesulfonate-catalyzed Friedel-Crafts alkylation of aromatic compounds with secondary alcohol methanesulfonates
Kotsuki, Hiyoshizo,Oshisi, Takeshi,Inoue, Motoshi
, p. 255 - 256 (1998)
Scandium(III) inflate was found to be an efficient catalyst for the Friedel-Crafts alkylation of aromatic compounds with methanesulfonates derived from secondary alcohols; the catalyst can be reused without a significant loss of activity.
Terminal-Selective Functionalization of Alkyl Chains by Regioconvergent Cross-Coupling
Dupuy, Stéphanie,Zhang, Ke-Feng,Goutierre, Anne-Sophie,Baudoin, Olivier
, p. 14793 - 14797 (2016/11/23)
Hydrocarbons are still the most important precursors of functionalized organic molecules, which has stirred interest in the discovery of new C?H bond functionalization methods. We describe herein a new step-economical approach that enables C?C bonds to be constructed at the terminal position of linear alkanes. First, we show that secondary alkyl bromides can undergo in situ conversion into alkyl zinc bromides and regioconvergent Negishi coupling with aryl or alkenyl triflates. The use of a suitable phosphine ligand favoring Pd migration enabled the selective formation of the linear cross-coupling product. Subsequently, mixtures of secondary alkyl bromides were prepared from linear alkanes by standard bromination, and regioconvergent cross-coupling then provided access to the corresponding linear arylation product in only two steps.
Effects of the carbon support nature and ruthenium content on the performances of Ru/C catalysts in the liquid-phase hydrogenation of benzaldehyde to benzyl alcohol
Mironenko, Roman M.,Belskaya, Olga B.,Zaikovskii, Vladimir I.,Likholobov, Vladimir A.
, p. 923 - 930 (2015/08/06)
Abstract The hydrogenation of benzaldehyde in ethanol medium in the presence of Ru/C catalysts was shown to proceed with the preferential formation of benzyl alcohol without subsequent hydrodeoxygenation into toluene. An increase in ruthenium content of t
Microwave-assisted silica-supported aluminum chloride-catalyzed Friedel-Crafts alkylation
Zupp, Laurine R.,Campanella, Veronica L.,Rudzinski, Diandra M.,Beland, Franois,Priefer, Ronny
, p. 5343 - 5346 (2012/10/30)
Microwave irradiation is a popular method in organic synthesis to achieve high yields in shorter reaction times. This decreases total 'man-hours' in a synthetic setting. Another technique used in organic chemistry to decrease manual manipulations, is solid support reagents. The benefits of this approach is that upon completion of a reaction, a simple filtration can be performed which expedites the work-up and also produces less organic waste. Friedel-Crafts alkylation has been explored using microwave chemistry as well as with solid-supported reagents. In comparison with traditional heating, as well as with AlCl3, superior yields were observed with silica-gel bound aluminum chloride (Si-AlClx) when microwave irradiated for only 5 min.
Iron(II) complexes with functionalized amine-pyrazolyl tripodal ligands in the cross-coupling of aryl Grignard with alkyl halides
Xue, Fei,Zhao, Jin,Hor, T. S. Andy
experimental part, p. 8935 - 8940 (2011/10/19)
Structurally distinctive Fe(ii) complexes with furan, thiophene and pyridine functionalized amine-pyrazolyl tripodal hybrid ligands have been synthesized and crystallographically characterized. The tether substituent at the central amine plays an active role in determining the coordination mode of the ligand and the metal geometry. All complexes are catalytically active towards cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides with β-hydrogen under ambient conditions. ESI-MS spectra analysis revealed the ligand-stabilised Fe(ii) and Mg(ii) species. The Royal Society of Chemistry 2011.
Synergistic effects of alkali metals in the alkylation of naphthalene and toluene with ethene in the ArH-alkali metal systems in THF (ArH - naphthalene, phenanthrene)
Rummel,Yunusov,Kalyuzhnaya,Shur
experimental part, p. 1467 - 1472 (2009/09/06)
The use of mixtures of metallic lithium and sodium in the naphthalene-alkali metal systems in THF leads to a synergistic acceleration of the naphthalene alkylation with ethene at room temperature and atmospheric pressure. The greatest synergistic effect is observed at a Li:Na molar ratio of 2:1. Under these conditions, the overall conversion of naphthalene into alkylation products (linear 1-alkylnaphthalenes and their dihydro derivatives) attains 88% after 24 h (a (Li + Na):C10H8 ratio is 2:1). The use of mixtures of metallic lithium and potassium in such systems results, however, in a synergistic retardation of the alkylation process. The strongest retarding effect is observed at a Li:K molar ratio of 1:1. The efficiency of the toluene alkylation with ethene in the naphthalene-alkali metal systems in THF is also increased on the replacement of lithium or sodium by their mixtures. The best results are obtained at a Li:Na molar ratio of 1:3. With this Li:Na ratio, toluene is almost quantitatively converted into linear and α-branched higher monoalkylbenzenes (24 h, (Li + Na):C10H8 = 2:1). The rate of the naphthalene alkylation with ethene in the presence of toluene is enhanced as well on an introduction of mixtures of lithium and sodium into the system. However the maximum of the activity is shifted here towards higher lithium content (Li:Na = 1:1). A similar synergistic effect of lithium and sodium was found on studying the toluene alkylation with ethene in the phenanthrene-Li-Na systems in THF (a (Li + Na):phenanthrene ratio is 3:1). An addition of potassium to sodium also considerably increases the efficiency of the toluene and naphthalene alkylation with ethene in the naphthalene-based systems. The possible mechanism of the alkali metal synergism in the above-mentioned alkylation reactions is discussed.
Activation of C-H bonds of hydrocarbons by the ArH-alkali metal systems in THF (ArH - naphthalene, biphenyl, anthracene, phenanthrene, trans-stilbene, pyrene). Alkylation of naphthalene and toluene with ethene
Rummel,Ilatovskaya,Yunusov,Kalyuzhnaya,Shur
experimental part, p. 1459 - 1466 (2009/09/06)
Systems based on naphthalene and alkali metals (Li, Na, K) in THF are able to induce the alkylation of naphthalene with ethene at room temperature and atmospheric pressure. The highest activity in this reaction is exhibited by the naphthalene-potassium system which converts naphthalene into 1-ethylnaphthalene (1) and small amounts of two isomeric dihydro derivatives of 1 in a yield of 85% (24 h, K:C10H8 = 2:1). The same alkylation products are formed when metallic sodium is used instead of potassium. The interaction of ethene with the naphthalene-lithium system (24 h, Li:C10H8 = 2:1) affords 1 together with 1-n-butylnaphthalene (4), 1-n-hexylnaphthalene (5), 1-n-oktylnaphthalene (6) and dihydro derivatives of 5 and 6 in a total yield of 60%. Alkylation of toluene with ethene in the naphthalene-alkali metal systems leads to the formation of higher monoalkylbenzenes. The greatest toluene conversion (48%, 24 h) is observed on using the lithium-containing system (Li:C10H8 = 2:1), in the presence of which a mixture of n-propylbenzene (11), n-pentylbenzene (12), 3-phenylpentane (13) and 3-phenylheptane (14) is produced from ethene and toluene. On the replacement of lithium by sodium or potassium, only 11 and 13 are obtained. A treatment of biphenyl, phenanthrene, trans-stilbene, pyrene and anthracene with alkali metals in THF also gives systems capable of catalyzing the alkylation of toluene with ethene at 22 °C. Of particularly active is the stilbene-lithium system (Li:stilbene = 3:1) which converts toluene into a mixture of 11-14, n-heptylbenzene and 5-phenylnonane in a yield of 58%. In all cases, the rate of the alkylation considerably increases in the presence of the solid phase of alkali metal. The mechanism of the reactions found is discussed.
Carbon-carbon coupling of C(sp3)-F bonds using alumenium catalysis
Gu, Weixing,Haneline, Mason R.,Douvris, Christos,Ozerov, Oleg V.
experimental part, p. 11203 - 11212 (2009/12/05)
Dialkylalumenium cation equivalents coupled with the hexabromocarborane anion function as efficient and long-lived catalysts for alkylation of aliphatic C-F bonds (alkylative defluorination or AlkDF) by alkylaluminum compounds. Only C(sp3)-F bo
SYNTHESIS OF PROPYLBENZENE FROM TOLUENE AND ETHYLENE
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Page/Page column 5-7, (2008/12/04)
Methods are provided for producing alkylbenzenes, such as propylbenzene, from aromatics, such as toluene, and alkenes, such as ethylene. Such methods comprise combining the toluene with about 100 ppm to about 350 ppm water and alkali metal catalyst, activating the catalyst at about 18O°C to about 220°C, adding the ethylene and conducting the synthesis reaction at about 130°C to about 15O°C.
