Copper(i) anchored on a covalent triazine framework/ionic liquid as a recyclable catalytic system for cyclization of propargylic amines with CO2 under ambient conditions†

Abstract

The conversion of carbon dioxide (CO₂) into high-value organic molecules as a C1 building block offers a promising strategy to mitigate escalating atmospheric CO₂ accumulation. A key challenge in this field lies in developing efficient methodologies for synthesizing 2-oxazolidinones via propargylamine–CO₂ coupling reactions under ambient conditions, using non-noble metal-based heterogeneous catalysts. To address this, we report a novel hybrid catalyst system: a Cu(I)-functionalized covalent triazine framework (CTF). This catalyst enables the carboxylative cyclization of propargylamines with CO₂ to form 2-oxazolidinones at room temperature under atmospheric pressure in an ionic liquid, demonstrating exceptional catalytic performance. The CTF's nitrogen-rich porous architecture provides well-defined coordination environments for Cu(I) species, creating structurally robust active sites that ensure high catalytic efficiency and recyclability without significant activity loss. Notably, this work showcases the direct utilization of CO₂ from automobile exhaust emissions, exemplifying a sustainable approach for chemical synthesis that leverages cost-effective, environmentally benign CO₂ feedstocks.