Programmable Macrocyclic Enoate-Mediated Regioselective ROMP for Sequence-Controlled Polymer Synthesis

Entropy-driven ring-opening metathesis polymerization (ED-ROMP) of macrocyclic olefins with built-in sequence information has emerged as a powerful strategy for synthesizing sequence-controlled polymers. However, conventional cyclic templates often require intricate synthetic procedures to achieve high regio- and stereospecificity. Leveraging the inherent selectivity of olefin cross-metathesis between acrylates and terminal olefins, we developed an easily accessible macrocyclic olefin template featuring an enoate motif. The information within the sequence-defined cyclic enoate monomer can be precisely encoded via an iterative stepwise growth approach. The resulting sequence-controlled polymers, with tunable sequence compositions, serve as an excellent model system for investigating how specific monomer sequences influence the polymer physical properties. This work expands the library of sequence-programmable macrocyclic monomers compatible with a tail-to-head-type polymerization strategy, offering a versatile and efficient platform for precision macromolecular engineering.