The Oxidative Coupling of Alkyl Aryl Ketones by Iron(III) Chloride

• Published in: Bulletin of the Chemical Society of Japan Vol. 46; no. 7; pp. 2211 - 2215
• Main Authors: Inoue, Hiroo, Sakata, Mitsuya, Imoto, Eiji
• Format: Journal Article
• Language: English
• Published: The Chemical Society of Japan 01.07.1973
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.46.2211

The oxidative carbon-carbon coupling of two enolizable ketones, propiophenone and butyrophenone, with iron(III) chloride is investigated. The ketones are converted to γ-diketones(II) and 2,5-diphenylfurans(III) in high yields, while iron(III) chloride is reduced to iron(II) chloride. III is produced by the dehydration of II with iron(III) chloride and/or hydrogen chloride. During the reaction, iron(III) chloride is regenerated partially by the oxidation of iron(II) chloride with oxygen in the presence of hydrogen chloride. However, oxygen enhances the formation of III and the polymeric material. The addition of pyridine, calcium oxide, or zinc oxide to the iron(III) chloride-ketone system brings about the selective formation of α-chloroketones. A combination of iron(III) chloride with copper(II) chloride or oxide is effective for the oxidative coupling. Under irradiation, the reactions result both in oxidative coupling and in chlorination at the α-position of the carbonyl group, accompanied by chlorination at the β-position.