Preparation of 3-hydroxyquinolines from direct oxidation of dihydroquinolinium salts

RSC Adv. 2018 Nov 14;8(67):38166-38174. doi: 10.1039/c8ra07940d.

Abstract

A series of functionalized 3,4-dihydroquinolinium salts were prepared from the reaction of aryldiazonium salt with alkene in a nitrile solution. Further oxidation yielding either 3-hydroxyquinoline or quinoline products was investigated. A one-pot process from aryldiazonium salts, alkenes and nitriles leading to 3-hydroxyquinolines was also developed. Furthermore, an intramolecular trapping of an N-arylnitrilium ion with a vinyl group at the ortho position leading to 2-substituted quinolines was revealed.