Ring-expansion metathesis polymerization REMP

Another most recent and successful example concerns the ring-expansion metathesis polymerization (REMP) of cycloolefins using cyclic carbene-ruthenium complex. " In this reaction, the cyclic olefin coordinates onto the ruthenium active center before insertion into the cyclic carbene ring. 

Cyclic bottlebrush polymers are uniquely accessible in high yields through ring-expansion metathesis polymerization (REMP) (Figure 8.14). For example, the alkyne-containing macrocycle 27 was modified with PEG substituents to generate cyclic bottlebrush copolymer 28, which exists as a toroid [141]. To date, REMP has yielded bottlebrushes that serve as proof of concept, and it will be interesting to see whether this toroidal shape makes a difference in their function. 

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