4-Aryl-8-hydroxyquinolines from 4-chloro-8-tosyloxyquinoline using a Suzuki-Miyaura cross-coupling approach

4-Chloro-8-tosyloxyquinoline was successfully cross-coupled with various arylboronic acids in anhydrous Suzuki-Miyaura conditions. The protective tosyl group was stable during the anhydrous coupling. The use of tosyl protection in association with anhydrous Suzuki-Miyaura reaction conditions allows the use of commercially available but relative inert 5-chloro-8-hydroxyquinoline for the synthesis of 5-phenyl-8-hydroxyquinoline. Deprotection could easily be made by using suitable nucleophiles to afford the final 5-phenyl and 4-aryl-8-hydroxyquinolines in high yields. Under acidic conditions the tosyloxy group is sufficiently stable to allow selective further modification of acid labile functional groups. (C) 2008 Elsevier Ltd. All rights reserved.