cis-Selective Acyclic Diene Metathesis Polymerization Using Bulky Cyclometalated Ruthenium Carbene Catalysts

The regulation of the cis - trans configuration is important for investigating the structure-property relationship and fine-tuning the properties of olefin-containing polymers. While classic metathesis polymerization typically yields trans-enriched polymer backbones, the selective construction of all-cis-configured polyalkenamers was previously restricted to the use of strained cyclic olefins or methyl/ethyl-capped acyclic cis-dienes as monomers. Here, we report an efficient and diverse-oriented cis-selective acyclic diene metathesis (ADMET) using readily available terminal acyclic dienes, which achieves a high cis-percentage of up to 99% and satisfactory molar mass by a bulky cyclometalated ruthenium-carbene catalyst. This method is further compatible with trans-olefin embedded triene monomers, providing a convenient tool for constructing alternative cis - trans configurations in polyalkenamers. A cis-ADMET-prepared and G2-degradable polymer was also explored. This work expands the possibilities for precision polymer synthesis and may offer new avenues for material design.