Norbomadienes copolymerization

A key impetus in the study of these materials was the pursuit of catalytic CO/olefin copolymerization, reactivity to which 431-438 and 447 and their parent alkyls are entirely inert. Though 448 has been found to react with norbomadiene, affording the insertion product Tp PdC7H8C (O)p-Tol) (449), it does so slowly (>1 day). However, when the parent p-Tolyl complex 440 is simultaneously exposed to both CO and norbor-nadiene, catalytic copolymerization ensues, affording the polyketone within hours (Section IV.A).140 141... 

Other catalytic systems were used recently, namely a Ddppi system (67, Scheme 8.14) for dicyclopentadiene and di(methylcyclopentadiene) [96] and imino-phosphine complexes (Scheme 8.19, 97 and 98) or hybrid terdentate carbene hgand complexes (99) [133] for norbornene. Furtlierrnore, the copolymerization of various substituted norbomadienes and norbomenes has been achieved with Rh6(CO)i6 under water gas shift reaction conditions (55 ""C, water and 100 atm CO) [134],... 

Disulfide-bridged oligoferrocenes 3.18 (M <3500) were prepared in an attempt to copolymerize ferrocenedithiol with norbomadiene in the presence of AIBN in toluene [55, 56]. Rather than the expected radical-induced polyaddition [57] to give 3.17 (Eq. 3.8), condensation of the ferrocene monomer was observed with norbor-nene and nortricydane units as end-groups (Eq. 3.9). The isolated oligomers (3.18) were characterized by NMR spectroscopy and field-desorption mass spectrometry, and possessed a chain length of 2-12 repeat units as determined by GPC. 

Copolymerizations of ethene with bicycUc olefins, such as 2,5-norbomadiene and 5-vinyl-2-norbomene, have been investigated with metallocene catalysts. The secondary groups do not interfere with metallocene copolymerizations, and postpolymerization functionalization makes it possible to synthesize functionalized polyolefins [133-135]. 

Nishimura, X, Kameyama, A., Sakurai, X, and Nishikubo, X, Synthesis of polyesters carrying norbomadiene (NBD) moieties by the ring-opening copolymerization of glycidic esters containing NBD moieties with carboxyKc anhydrides and their photochemical reactions. Macromolecules, 29, 3818-3825, 1996. 

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