Arylation of Unsaturated Compounds by Diazonium Salts (The Meerwein Arylation Reaction)

Abstract

The arylation of olefinic compounds by diazonium halides with a copper salt catalyst was discovered by Meerwein. The Meerwein arylation reaction proceeds best when the olefinic double bond is activated by an electron attracting group Z, such as cyano, carbonyl, or aryl. The net result is the union of the aryl group from diazonium salt with carbon atom beta to the activating group, either by substitution of a beta hydrogen atom or the addition of Ar and Cl to the double bond. The reaction is a valuable synthetic tool. This chapter is confined to reactions in which a new carbon-carbon bond is formed between the aromatic ring of a diazonium salt and aliphatic unsaturated compound. Keywords: arylation; unsaturated compounds; diazonium salts; Meerwein arylation reaction; unsaturated component; quinones; arylation; cinnamic acid; maleic acid; side reactions; decarboxylation; experimental conditions