Conversion of CO2 into cyclic carbonates using an ionic porous organic cage

and epoxides, generating cyclic carbonates in high yields. This POC catalyst is highly efficient, achieving a maximum yield of up to 90% with a turnover number (TON) of 3000 without requiring reaction solvents. Moreover, with the synergistic effect of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), the catalytic performance can be further enhanced across a wide substrate range.