One-pot oxidative Groebke–Blackburn–Bienayme reaction of alcohols: using bio-supported and magnetically recyclable Fe2O3@cellulose and Fe2O3@cellulose–SO3H nanocomposites for the synthesis of 3-aminoimidazo[1,2-a]pyridines

Abstract

One-pot oxidative Groebke–Blackburn–Bienayme three-component reaction has been successfully developed with primary alcohols instead of their corresponding aldehydes in the presence of recyclable Fe2O3@cellulose and Fe2O3@cellulose–SO3H catalysts. In this work, an efficient protocol for the oxidative synthesis of 3-aminoimidazo[1,2-a]pyridines via an alcohol, 2-aminopyridine, and an isocyanide in excellent yields in the presence of a catalytic amount of Fe2O3@cellulose or Fe2O3@cellulose–SO3H as magnetically recoverable heterogeneous catalysts is described. The reaction workup is simple and the catalysts can be easily magnetically separated from the reaction medium and reused in subsequent reactions.