Alumina-Supported Copper(II) Halides as Friedel-Crafts Catalysts

1993 Fiscal Year Final Research Report Summary

• Project/Area Number: 04650784
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 有機工業化学
• Research Institution: Shibaura Institute of Technology
• Principal Investigator: KODOMARI Mitsuo Faculty of Shibaura Institute of Technology, Professor, 工学部, 教授 (50052824)
• Project Period (FY): 1992 – 1993
• Keywords: Friedel-Crafts catalyst / Supported reagent / Silica gel-supported zinc chloride / Benzylation / Alkylation / Alumina-supported copper (II) chloride

Research Abstract

Catalytic activity of copper (II) chloride in Friedel-Crafts benzylation was remarkably increased when copper (II) chloride was supported on neutral alumina. Free copper (II) chloride was inactive for the benzylation of benzenes with benzyl chloride. In contrast, alumina-supported copper (II) chloride catalyzed Friedel-Crafts benzylation of benzenes with benzyl chloride under mild conditions. The CuCl_2/Al_2O_3 catalyst is easily recovered from the reaction mixture and reused without a decrease in catalytic activity. Silica gel-supported zinc chloride showed a higher activity compared with CuCl_2/Al_2O_3. Benzylation of polymethylbenzenes catalyzed by ZnCl_2/SiO_2 gave selectively the corresponding monobenzylated compounds in high yields. Reaction of benzenes with bis(chloromethyl)benzene using ZnCl_2/SiO_2 as a catalyst gave the corresponding dibenzylbenzenes in high selectivity. For example, in the reaction of diphenylmethane, bis (4-benzylphenyl) -p-xylene was obtained in high yield. ZnCl_2/SiO_2 can be reused as well as CuCl_2/Al_2O_3.