Insertion of pillar[5]arene into Tröger's base-derived porous organic polymer for promoted heterogeneous catalytic performance in Knoevenagel condensation and CO2 fixation

Development of new metal-free heterogeneous catalysts has long been the focus of intense research interest. The integration of multifunctional monomers into the skeletons of porous organic polymers (POPs) provides an efficient pathway to achieve this goal. Herein, we rationally designed and successfully prepared a new Tröger's base (TB)-derived POPs by insertion of pillar[5]arene macrocycle as a positively auxiliary group. Combined the both merits of pillar[5]arene macrocycle and TB moiety, the as-prepared polymer was further explored as an effective metal-free heterogeneous catalyst and exhibited promoted catalytic performance in Knoevenagel condensation and CO2 conversion. This work provides a new strategy to fabricate metal-free heterogeneous catalysts based on macrocyclic POPs.