Industrial waste gas is one of the major sources of atmospheric CO2, yet the direct conversion of the low concentrations of CO2 in waste gases into high value‐added chemicals have been a great challenge. Herein, a copper‐based N‐heterocyclic carbene porous polymer catalyst (Cu@NHC‐1) for the direct conversion of low concentration CO2 into oxazolidinones was successfully fabricated via a facile copolymerization process followed by the complexation with Cu(OAc)2. A continuous flow device was designed to deliver a continuous and stable carbon source for the reaction. Due to the triple synergistic effect of its porous structure, nitrogen activation sites and catalytic Cu center, Cu@NHC‐1 shows highly efficient and selective adsorption, activation, and conversion of the low concentration CO2 (30 vol%). Its practical application potential is demonstrated by the ability to successfully convert the CO2 in lime kiln waste gas into oxazolidinones in satisfactory yields under mild conditions.

The anaerobic fermentation gas (AFG) with CO2 removed is a sustainable energy resource, and converting CO2 in AFG to value‐added chemicals can kill two birds with one stone. Herein, an ionic porous organic polymer (IPOP‐3) catalyst, with triply synergistic effect of its hydroxide anions, nitrogen activation sites and porous structure, is synthesized. IPOP‐3 exhibits an excellent ability to enrich and convert 50 vol.% CO2 by the reactions with various amines into corresponding formamides. The catalyst is also successfully applied to the N‐formylation of CO2 in AFG, and can be easily recovered and reused. The plausible mechanism for the catalytic N‐formylation is proposed. The hydroxide anion in IPOP‐3 activates the Si−H bond of phenyl silane which reacts with the captured CO2 to form formate anion to facilitate the subsequent conversion into formamide. Our work provides a new idea for the purification of AFG and the resource utilization of CO2.

3,4-dihydroquinolone is an important drug and biological compound molecule. o-halophenylacrylamides were cyclized by two-electron reduction under electrochemical catalysis to obtain the corresponding 3,4-dihydroquinolinone products. This electrochemical cyclization improves the selectivity...