Mechanical Force Induces Ylide‐Free Cycloaddition of Nonscissible Aziridines

The application of aziridines as nonvulnerable mechanophores is reported. Upon exposure to a mechanical force, stereochemically pure nonactivated aziridines incorporated into the backbone of a macromolecule do not undergo cis–trans isomerization, thus suggesting retention of the ring structure under force. Nonetheless, aziridines react with a dipolarophile and seem not to obey conventional reaction pathways that involve C−C or C−N bond cleavage prior to the cycloaddition. Our work demonstrates that a nonvulnerable chemical structure can be a mechanophore. The force awakens: Mechanical‐force‐induced cycloaddition of intact aziridine groups in a macromolecule with dipolarophiles does not follow the reaction pathways that occur under traditional thermal and photochemical conditions. The aziridines do not undergo cis–trans isomerization, thus suggesting retention of the ring structure under force. This demonstrates that nonvulnerable chemical structures can be attractive mechanophores.