A Triazine Based Porous Organic Polymer as an Efficient Hydrogen-Bond Donor and Acceptor Cooperative Heterogeneous Catalyst for the Synthesis of 2-Substituted Benzimidazoles

A novel hydrogen bond donor and acceptor cooperative catalyst based on a triazine cored porous organic polymer has been developed by a simple one pot synthesis. The catalyst was demonstrated to be highly efficient for the synthesis of 2-substituted benzimidazole and its derivatives under mild reaction condition. The major highlight of the catalyst is the presence of multiple potential sites for hydrogen bonding which facilitates hydrogen bond mediated electrophilic activation of the aldehyde carbonyl for the facile conversion to the 2-substituted benzimidazole. A plausible reaction mechanism of the catalysis has been proposed which is validated through Density Functional Theory calculations. The method developed offers the production of benzimidazoles by green catalytic procedure with fascinating properties such as one step preparation of catalyst, very good yield of product, mild reaction condition and reusability of the catalyst. Porous organic polymers (POPs) into very efficient materials for catalytic applications. This study focuses on the use of POPs as metal-free hydrogen bond donor-acceptor cooperative organocatalyst. Here we introduce a nitrogen abundant triazine based porous organic polymer named POP CCTAP as an efficient organocatalyst for the room temperature synthesis of pharmaceutically important compounds like 2-substituted benzimidazole scaffolds.image