The cooperation of porphyrin-based porous polymer and thermal-responsive ionic liquid for efficient CO2 cycloaddition reaction

The cooperation of catalyst and co-catalyst, together with efficient recycling, is one of the most important and still big challenges for CO2 cycloaddition reaction. Herein, we report a facile and atom-efficient method to synthesize a porous zinc-porphyrin-based framework (P-POF-Zn) as a catalyst for the synthesis of cyclic carbonates. It was demonstrated for the first time that the combination of P-POF-Zn and thermal-responsive ionic liquid [CPeDMAPy] Br (soluble in PO and PC at high temperature but not at room temperature) could efficiently catalyze the cycloaddition reaction of CO2 and propylene oxide to afford a turnover frequency of 433 h(-1). The high catalytic activity is mainly attributed to the efficient cooperation of P-POF-Zn (Lewis acid site) and [CPeDMAPy] Br (nucleophile). Both P-POF-Zn and [CPeDMAPy] Br could be fully recovered after reaction by simple filtration for stable recycling. This work demonstrates the efficiency of the combination of thermal-responsive reagents with solid catalyst for catalyzing chemical reactions via a cooperation activation pathway.