Oxanorbornenes: promising new single addition monomers for the metathesis polymerization.

Higher ring-opening metathesis propagation rates of -norbornene derivatives over derivatives are well established in the literature. Here, we report for the first time that -isomers of oxanorbornene derivatives show higher reactivity towards ring-opening metathesis with Grubbs' 3rd generation catalyst () than the corresponding -isomers. A very high selectivity for the reaction of with over the -isomers could be shown. Furthermore, single molecular addition of the -isomers with was observed. On the other hand, pure -monomers could successfully be homopolymerized. Mixtures of - and - monomers, however, prevented the homopolymerization of the -monomer. Such mixtures could successfully be copolymerized with cycloalkenes, resulting in alternating copolymers. An oxanorbornadiene derivative could be shown to undergo single addition reactions, exploited in the preparation of mono-end functional ROMP polymers. These could be selectively derivatized endgroup selective thiol-ene click reactions. A thiol and alcohol end functional ROMP polymer was synthesized, and the efficient end functionalization was confirmed by H NMR spectroscopy and MALDI-ToF spectrometry.