Co-catalyst and solvent free nitrogen rich triazole based organocatalysts for cycloaddition of CO₂ into epoxide

A general synthesis of triazole-based catalysts remains a significant challenge. Consequently, triazole-based catalysts are rarely studied. Herein, the first report is presented for the construction of cyclic carbonates using triazole-based organocatalysts, which is a crucial technology to a genuinely sustainable and atom-efficient economy. A series of triazole-based organocatalysts was synthesized, entirely characterized by FTIR, NMR, mass spectrometry, and elemental analysis. This work is mainly based on the construction of nucleophilic-electrophilic bifunctional catalysts (N-rich triazole ring-carboxylic group) combined with substituents, which evaluate the vital effect of substituents for the catalytic cycloaddition reaction of CO₂ into epoxide. In general, various systems required the Lewis basic site in the form of cocatalyst or solvent to be optimally effective. However, our designed catalyst contained Lewis basic and acidic sites. It, therefore, can catalyze the reaction proficiently without the aid of solvent, cocatalysts and can perform at ambient pressure of CO₂ (1 bar) to produce different cyclic carbonates. Moreover, the catalyst is reusable, maintaining the same activity along with remarkable catalyst stability.