cis-Selective Acyclic Diene Metathesis Polymerization of α,ω-Dienes

The cis/trans stereochemistryof repeating alkenes in polymers provides a powerful handle to modulatethe thermal and mechanical properties of these soft materials, butsynthetic methods to precisely dictate this parameter remain scarce.We report herein a cis-selective acyclic diene metathesis(ADMET) polymerization of readily available alpha,omega-dienemonomers with high functional group tolerance. Identification of ahighly stereoselective cyclometalated Ru catalyst allowed the synthesisof a broad array of polymers with cis contents upto 99%. This platform was leveraged to study the impact of the cis geometry on the thermal and mechanical properties ofpolyalkenamers, including an ABA triblock copolymer synthesized viaextension of a cis-rich telechelic polyoctenamerwith d,l-lactide. These results suggest that cis-selective ADMET affords an efficient strategy to tunethe properties of a variety of polymers.

Automated summary

The stereochemistry of repeating alkenes in polymers has a significant impact on the thermal and mechanical properties of soft materials. However, there are limited methods to precisely control this parameter. In this study, a cis-selective acyclic diene metathesis (ADMET) polymerization was successfully developed using a highly stereoselective cyclometalated Ru catalyst, allowing for the synthesis of polymers with high cis contents up to 99%. The impact of cis geometry on the properties of polyalkenamers was investigated, demonstrating that cis-selective ADMET is an efficient strategy to tune the properties of various polymers.