Tandem approach for the synthesis of imidazo[1,2-a]pyridines from alcohols

Propylphosphonic anhydride ((R) T3P) is shown to be an effective and mild reagent for the one-pot synthesis of imidazo[1,2-a]pyridines from a variety of alcohols. Alcohols are oxidized in situ to aldehydes under mild conditions, which in turn undergo a three-component reaction with various 2-aminopyridines and isocyanides to afford imidazo[1,2-a]pyridines in excellent yields. T3P acts as an activator for both DMSO in oxidation reaction and the Schiff base in nucleophilic addition reaction with isocyanides. (C) 2012 Elsevier Ltd. All rights reserved.