Cycloaddition reactions of glycine imine anions to phenylazocarboxylic esters - a new access to 1,3,5-trisubstituted 1,2,4-triazoles

Phenylazocarboxylic tert-butyl esters have recently been shown to be highly versatile building blocks due to their ability to undergo nucleophilic aromatic substitutions under mild conditions, particularly well with [F-18]fluoride, and to act as precursors for aryl radicals. In this article, we now report first examples for cycloaddition reactions to phenylazocarboxylates. In a one-pot reaction with readily accessible glycine imines, a variety of highly substituted 1,2,4-triazoles could be obtained. (C) 2015 Elsevier Ltd. All rights reserved.