Copper-dithiocarbamate decorated graphitic carbon nitride as a robust heterogeneous cross-coupling catalyst for diaryl ether synthesis

A novel copper/dithiocarbamate-decorated graphitic carbon nitride (g-C₃N₄@DTC-Cu) catalyst was developed and applied as a robust, heterogeneous catalytic system for the C–O cross-coupling reaction of aryl halides with phenols to form diaryl ethers for the first time. Interestingly, the dithiocarbamate ligand effectively stabilized Cu(I) species on the carbon nitride surface resulted in enhanced dispersion, redox accessibility, and resistance to leaching under basic conditions. Comprehensive characterizations (XRD, SEM, TEM, IR, AFM, NMR, ICP-OES, BET, and EDS) have confirmed uniform metal–ligand anchoring and strong Cu–N/C coordination in the newly synthesised catalyst. Furthermore, the catalyst exhibited high reactivity toward diverse substrates bearing electron-donating and electron-withdrawing groups, affording diaryl ether derivatives in excellent yields. Recyclability tests demonstrated sustained catalytic performance over multiple cycles with negligible copper loss. The synergistic interaction between Cu centres and the conjugated C₃N₄ framework underlies the enhanced efficiency and durability of g-C₃N₄@DTC-Cu, offering a green and scalable platform for ether bond formation in fine-chemical synthesis.