Functionalized Covalent Triazine Framework (CTF) for Catalytic CO2 Fixation and Synthesis of Value-Added Chemicals

• Published in: Crystal growth & design 2024-10, Vol.24 (19), p.7878-7887
• Main Authors: Kishan, Ram, Rani, Pooja, Singh, Gulshan, Nagaraja, C. M.
• Format: Article
• Language: English
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.4c00739

The capture and utilization of CO2 for sustainable synthesis of commodity products represent a significant move toward mitigating the growing atmospheric CO2 content for environmental remediation. Meanwhile, Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions are considerable tools for generating valuable feedstock compounds, such as agrochemicals, natural products, drugs, etc. In this regard, we present the strategic incorporation of catalytically active Pd­(II) in a porous covalent triazine framework (CTF) composed of bipyridine sites (bpy-CTF) by postsynthetic modification. Notably, Pd­(II) anchored framework, Pd­(II)@bpy-CTF, demonstrated exceptional catalytic function in the cyclization of CO2 with propargylic amines and in cross-coupling reactions (Heck and Suzuki-Miyaura), producing high-value commodity products under mild conditions. Further, various electronically and sterically challenging substrates were converted into the corresponding products by using Pd­(II)@bpy-CTF as a catalyst. Notably, Pd­(II)@bpy-CTF exhibited efficient reusability, sustaining eight catalytic cycles without substantial degradation. The exceptional catalytic behavior of Pd­(II)@bpy-CTF is accredited to high abundance of N-rich triazine units and the exposed catalytic Pd­(II) sites within the one-dimensional channels of the CTF. This work establishes the potential utility of triazine-based frameworks for utilizing carbon dioxide and stabilizing catalytically active metal ions in developing highly recyclable catalysts to generate value-added chemicals efficiently.