Aryne Polymerization Enabled by Pyrazole-Induced Nucleophilic Aromatic Substitution

Despite the widespread use of arynes in organic synthesis, their polymerization remains a significant challenge due to the intrinsic instability and short lifetime of aryne intermediates. Here, we report a method for aryne polymerization using a simple organonucleophile, <i>N</i>-arylpyrazole, as an initiator. This polymerization proceeds via a unique pyrazole-induced nucleophilic aromatic substitution mechanism, facilitating the formation of poly(<i>ortho</i>-arylene)s with narrow polydispersity and well-defined structures. The high chemical stability of <i>N</i>-arylpyrazole allows for a broader scope of applications, including aryne polymerization at the side chain of preformed polymers (graft polymerization) and the synthesis of star-shaped poly(<i>ortho</i>-arylene)s.