Cooperative ruthenium complex catalyzed multicomponent synthesis of pyrimidines

Abstract

A new set of 2-(2-benzimidazolyl) pyridine ligand based air and moisture stable ruthenium complexes were synthesized and characterized. The catalytic behaviors of these complexes were evaluated towards the multicomponent synthesis of highly substituted pyrimidines directly from various amidines, primary alcohols, and secondary alcohols. Among all the metal complexes, 2-hydroxypyridine and benzimidazole fragments containing complex A showed the best reactivity in this reaction. In addition, it was observed that the N–H proton of benzimidazole and the hydroxyl group of pyridine played a critical role in enhancing catalytic activity. Several control experiments and mechanistic studies were carried out to understand this multicomponent synthesis of pyrimidines using complex A.