Ring-opening metathesis polymerization (ROMP) is used extensively in both industrial and fine-chemical synthesis to convert feedstock cyclic olefins into high-value polymers. These unique polymerizations have been enabled by a variety of heterogeneous and homogeneous transition metal catalysts, including those based on tungsten, titanium, tantalum, niobium, rhenium, iron, and especially ruthenium and molybdenum complexes (Figure ). While the impact of these reactions on the field of chemistry, and indeed human society, has been profound, there are some wellrecognized drawbacks to the use of transition metal reagents. In particular, issues of toxicity, expense, scarcity, and complex purification can complicate the utilization of ROMP polymers. In addition, certain applications such as those involving biomedical devices or electronics are incompatible with polymeric materials that contain metal impurities. Thus, there has been an interest in the discovery of non-metal alternatives for ROMP. Most notable in this regard, Boydston developed an elegant photoredox-mediated ROMP that utilized vinyl ethers as the propagating functionality. Despite the highly creative and useful nature of this chemistry, issues of generality and scalability present challenges for its wider adoption. Thus, the development of alternatives to metal-based ROMP chemistries remains a goal of high interest.