Microwave-Assisted Generation and Capture by Azoles of ortho-Quinone Methide Intermediates under Aqueous Conditions

Abstract

An efficient activator-free protocol for the coupling of o-hydroxybenzyl alcohols and azoles in water has been developed. This C–N bond-formation process is supposed to proceed through an ortho-quinone methide intermediate. A broad range of o-hydroxybenzyl alcohols that include those with alkenyl and alkynyl functionalities is compatible with this protocol. In most cases, the products are isolated in good to excellent yields without chromatographic purification. Preliminary results demonstrated that this methodology can also be used for the generation and trapping of isomeric para-quinone methide intermediates.