Functionalized Covalent\nTriazine Framework (CTF) for\nCatalytic CO<sub>2</sub> Fixation and Synthesis of Value-Added Chemicals

The capture and utilization of CO<sub>2</sub> for sustainable\nsynthesis\nof commodity products represent a significant move toward mitigating\nthe growing atmospheric CO<sub>2</sub> content for environmental remediation.\nMeanwhile, Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions\nare considerable tools for generating valuable feedstock compounds,\nsuch as agrochemicals, natural products, drugs, etc. In this regard,\nwe present the strategic incorporation of catalytically active Pd(II)\nin a porous covalent triazine framework (CTF) composed of bipyridine\nsites (bpy-CTF) by postsynthetic modification. Notably, Pd(II) anchored\nframework, Pd(II)@bpy-CTF, demonstrated exceptional catalytic function\nin the cyclization of CO<sub>2</sub> with propargylic amines and in\ncross-coupling reactions (Heck and Suzuki-Miyaura), producing high-value\ncommodity products under mild conditions. Further, various electronically\nand sterically challenging substrates were converted into the corresponding\nproducts by using Pd(II)@bpy-CTF as a catalyst. Notably, Pd(II)@bpy-CTF\nexhibited efficient reusability, sustaining eight catalytic cycles\nwithout substantial degradation. The exceptional catalytic behavior\nof Pd(II)@bpy-CTF is accredited to high abundance of N-rich triazine\nunits and the exposed catalytic Pd(II) sites within the one-dimensional\nchannels of the CTF. This work establishes the potential utility of\ntriazine-based frameworks for utilizing carbon dioxide and stabilizing\ncatalytically active metal ions in developing highly recyclable catalysts\nto generate value-added chemicals efficiently.