Harnessing the Dual Properties of Thiol-Grafted Cellulose Paper for Click Reactions: A Powerful Reducing Agent and Adsorbent for Cu

A new approach exploiting the dual properties of thiol‐grafted cellulose paper for promoting copper‐catalyzed [3+2]‐cycloadditions of organic azides with alkynes and adsorbing residual copper species in solution was developed. The thiol‐grafted cellulose paper, used as a paper strip, effects the reduction of CuII to catalytically active CuI and acts as a powerful adsorbent for copper, thereby facilitating the work‐up process and leaving the crude mixture almost free of copper residues after a single filtration. Looks good on paper: An approach that exploits the dual properties of thiol‐grafted cellulose paper for promoting copper‐catalyzed [3+2]‐cycloaddition of organic azides with alkynes and adsorbing residual copper species in solution was developed. Thiol‐grafted cellulose paper effects the reduction of CuII to catalytically active CuI and acts as a powerful adsorbent for copper, thereby facilitating the work‐up process.