Selective synthesis of unsymmetrical 2,2′-dihydroxylated biaryls via electrophilic arylation of metal phenolates with p-benzoquinone monoketals

Abstract

Unsymmetrical 2,2′-dihydroxylated biaryls are obtained by arylation of phenols with p-benzoquinone monoketals in the presence of EtAlCl₂. The reaction consists of an unusual and highly selective electrophilic attack at the α-position of the monoketal. A crystal structure determination of biaryl, 1-(2-hydroxy-5-methoxyphenyl)-2-hydroxynaphthalene, 3fx is presented.