ROMP with click chemistry

More recently, ring opening metathesis polymerization (ROMP) has been used to prepare telechelic liquid crystalline polymers that carry azide end groups which can be crosslinked with a triacetylene species using the well known copper catalyzed click chemistry [22]. 

Due to it s highly efficient and orthogonal nature, copper-catalyzed click chemistry is an attractive route to post-polymerization functionalization of ROMP copolymer backbones yielding amphiphilic micellar nanoparticles [103, 104]. However, it should be noted that post polymerization modification is necessary to yield azide or acetylene modified polymers, as azide and acetylene functionalities are not compatible with current ROMP catalysts. Ohe and coworkers [104] have synthesized amphiphihc triblock copolymers capable of assembly into discrete micellar nanoparticles by clicking an acetylene-modified hexaethylene... 

Scheme 9.4 Route to hydrogen-bonded polymers by combining ROMP and azide/alkyne click chemistry, (a) Direct polymerization approach [13, 17], ONBEs with thymine and Hamilton-receptor functionalities, 22a and b via azide/alkyne click reaction, followed by polymerization...

Azides are traditionally hard to incorporate into monomers for ROMP because of their adverse interactions with the catalyst. However, postfunctionalization of an alkyl bromide may be used. As an example, a norbomene bearing a dendrimer capped with an alkyl bromine was successfully used to form diblocks, which upon polymerization was substituted for the azide. Click chemistry with Cgo formed dendritic side chains bearing up to three Cso units though only half of the potential sites were found to be reactive this was attributed to steric bulk of the Ceo groups as similar chemistry with zinc porphyrins went to completion (Figure 28). 

Figure 3.10 Synthesis of glycopolymer via ROMP and its conjugation to ChSA using click chemistry. ChSA is represented by solid sphere in the scheme. Reproduced with permission from T. Lipinski, P.I. Kitov, A. Szpacenko, E. Paszkiewicz and D.R. Bimdle, Bioconjugate Chemistry, 2011,22, 274. 2011, American Chemical Society [27]...

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