Ethynylsulfone‐Based Phenol‐Yne Click Polymerization Toward Multiple Stimulus‐Responsive Poly( <i>β</i> ‐aryloxylvinylsulfone)s

Abstract We reported a metal‐free ethynylsulfone‐based phenol‐yne click polymerization for the efficient synthesis of stereoregulated poly( β ‐aryloxylvinylsulfone)s (PAVSs), a new class of polymers exhibiting inherent responsiveness to multiple stimuli. This polymerization exhibits superior reactivity, yielding high‐molecular‐weight polymers whose stereochemistry ( Z / E configuration) can be precisely modulated by catalysts, monomer concentration, and solvents. The resulting Z ‐ and E ‐enriched PAVSs demonstrate distinct thermal and mechanical properties, highlighting the impact of stereochemical control on material performance. Furthermore, new stimulus‐induced transformations have been developed on the PAVS platform. A catalyst‐free amine exchange reaction enables both precise polymer degradation and direct polymer‐to‐polymer conversion under mild conditions. Moreover, an unprecedented C═C bond cleavage reaction between PAVSs and N,N' ‐diethylethylenediamine affords methylated products, representing a rare example of alkene bond scission via simple diamine treatment. A photoinduced rearrangement reaction has also been established, leading to significant fluorescence enhancement upon UV irradiation. This photochemical behavior underpins potential applications in secure information encoding and encrypted communication.