heteropoly acids such as 12-tungstophosphoric, molybdophosphoric, and tungstosilicicacidsefficiently catalyzed Friedel–Crafts alkylation and acylation reactions of aromatic hydrocarbons with 1-octene, benzyl chloride and benzoyl chloride in the liquid phase. The catalytic activity of heteropoly acid was generally enhanced when supported on silica. Silica-supported tungstosilicicacid worked as an
Adsorption and catalytic properties of sulfated aluminum oxide modified with cobalt ions
作者:S. N. Lanin、A. A. Bannykh、E. V. Vlasenko、I. N. Krotova、O. N. Obrezkov、M. I. Shilina
DOI:10.1134/s0036024417010150
日期:2017.1
The adsorption properties of sulfatedaluminum oxide (9% SO 2-4 /γ-Al2O3) and a cobalt-containing composite (0.5%Сo/SO 2-4 /γ-Al2O3) based on it are studied via dynamic sorption. The adsorption isotherms of such test adsorbates as n-hydrocarbons (C6–C8), benzene, ethylbenzene, chloroform, and diethyl ether are measured, and their isosteric heats of adsorption are calculated. It is shown that the surface
Detailed Characterization of <i>p</i>-Toluenesulfonic Acid Monohydrate as a Convenient, Recoverable, Safe, and Selective Catalyst for Alkylation of the Aromatic Nucleus
作者:Mathew P. D. Mahindaratne、Kandatege Wimalasena
DOI:10.1021/jo971832r
日期:1998.5.1
Alkylation of the aromatic nucleus, an important reaction in industry and synthetic organic chemistry, has traditionally been carried out by the well-known Friedel-Crafts reaction employing Lewis acid catalysts such as AlCl3 and BF3 or by using highly reactive organometallic reagents. Although protic acids such as anhydrous HF and concentrated H2SO4 have also been used in the alkylation of the aromatic nucleus, the notoriously corrosive, highly toxic, and hazardous nature of these agents has precluded their common use under ordinary laboratory conditions. Various organic sulfonic acids have, on occasion, been used as catalysts in Friedel-Crafts alkylations, but to our knowledge the chemistry and the scope of these reactions for common laboratory use have never been exploited in detail. In the present study we have characterized commercially available p-toluenesulfonic acid monohydrate (TsOH) as an efficient catalyst for the intermolecular coupling of the aromatic nucleus with activated alkyl halides, alkenes, or tosylates under mild conditions in an open atmosphere. In comparison to conventional Friedel-Crafts catalysts such as AlCl3, BF3, HF, and concentrated H2SO4, the extent of the formation of undesired products from side reactions such as transalkylation, polymerization, etc. was minimal with the TsOH-catalyzed reaction. The ability to recover and reuse the catalyst from the reaction mixtures, minimal generation of environmentally unfriendly waste, high specificity of the reaction, and the low cost of the catalyst are important advantages of the TsOH catalyst over the other conventional Friedel-Crafts catalysts.
Selective hydrogenation of substituted dienes catalyzed by an organoyttrium complex
作者:Gary A. Molander、John O. Hoberg
DOI:10.1021/jo00038a004
日期:1992.6
Cp*2YMe(THF) has been developed as an efficient catalyst for the selective reduction of substituted dienes.
Olson, Industrial and Engineering Chemistry, 1960, vol. 52, p. 835