Organosilane sulfonated graphene oxide in the Biginelli and Biginelli-like reactions

Abstract

Organosilane sulfonated graphene oxides (SSi-GO) have been synthesized by a two-step procedure involving the grafting of graphene oxide (GO) using 3-chloropropyltriethoxysilane (CCPTES) and subsequent oxidation using sulfanilic acid. It has been shown that organosilane sulfonated graphene oxide (SSi-GO) exhibits a superior catalytic performance to produce pyrimidines in the Biginelli and Biginelli-like reactions. This stronger acidity corresponds to the cooperative effects of the aryl sulfonic acid groups and other kinds of acid sites (carboxylic acids). However, the acidic functionalities bonded to the SSi-GO surface are stable under the catalytic reaction conditions resulting in its efficient reuse.