Ring opening norbomene

Ring-Opening Metathesis Polymerization. Several new titanacyclobutanes have been shown to initiate living ring-opening metathesis polymerization (ROMP) systems. These have been used to make diblock and triblock copolymers of norbomene [498-66-8] (N) and its derivatives (eg, dicyclopentadiene [77-73-6] (D)) (Fig. 2) (41). 

The monomer, norbomene (or bicyclo[2.2.l]hept-2-ene), is produced by the Diels-Alder addition of ethylene to cyclopentadiene. The monomer is polymerised by a ring-opening mechanism to give a linear polymer with a repeat unit containing both an in-chain five-membered ring and a double bond. Both cis-and trans- structures are obtainable according to the choice of catalyst used ... 

Since it is known that the cyclopentene ring of norbomene can be easily opened by methylidene carbene complex Ih, bicyclic compound 66 has been synthesized from norbomene derivative 65 having an alkene part in a sidechain in the presence... 

Polycycloolefins are prepared by ring opening metathesis polymerization (ROMP) using transition metal catalysts [31], By far the most commonly studied monomer is dicyclopenta-diene (Fig. 1.7). Cycloolefins with high ring strains like norbomenes and their analogs polymerize very fast and the polymerizations are quite exothermic. Metathesis catalyst systems tend to be sensitive to the presence of polar compounds and the polymerization rates... 

II), on a mesoporous support having a hexagonal unit cell. The catalyst was used to prepare 5-norbomene and cyclooctadiene copolymers by ring-opening metathesis polymerization. 

The best known polymerization of norbomene is the ring opening metathesis polymerization. The reaction is technically applied in the Norsorex process (7). 

N. Miyaki, Y. Miyamoto, S. Fukuhara, and T. Ootsuki, Norbomene derivative and norbomene polymer obtained therefrom through ring opening polymerization, US Patent 6 846 890, assigned to JSR Corporation (Tokyo, JP), January 25, 2005. 

Ruthenium complexes mediate the hydroamination of ethylene with pyridine.589 The reaction, however, is not catalytic, because of strong complexation of the amine to metal sites. Iridium complexes with chiral diphosphine ligands and a small amount of fluoride cocatalyst are effective in inducing asymmetric alkene hydroamination reaction of norbomene with aniline [the best enantiomeric excess (ee) values exceed 90%].590 Strained methylenecyclopropanes react with ring opening to yield isomeric allylic enamines 591... 

Because of its favorable kinetic and thermodynamic properties, norbomene can be polymerized with simple transition-metal halogenides.99 116 Even RuC13, which is not active in other metathesis reactions, is effective in the ring-opening polymerization of norbomene.117118 Developments in the early 1990s include the use of... 

Ring opening of norbomene by Mo, W, Re, Os, Ru, and Ir compounds taking place at the double bond results in polymers with a complete range of cis/trans character, but the cyclopentane rings are always cis-1,3 enchained ... 

Much less is known about the ring-opening polymerization of norbomadiene. Surprisingly, OSCI3, a nonselective catalyst in the polymerization of norbomene, was found to yield an all-cis polymer.121... 

Exclusive ring opening of the anti compound of a mixture of syn- and anti-1-methylbicyclo[2.2.1]heptene-2 in the presence of Ru-, Os-, Ir-, W-, and Re-based catalysts was observed116 proving that the exo face of norbomene is highly reactive while the endo face is inert toward metathesis. 

S. T. Nguyen, L. K. Johnson, R. H. Grubbs, and J. W. Ziller, Ring-Opening Metathesis Polymerization (ROMP) of Norbomene by a Group VIII Carbene Complex in Protic Media, J. Am. Chem. Soc. 114, 3974-3975 (1992). 

The resulting substituted norbomenes can be interesting as monomers for addition or ring-opening polymerization reactions. 

Mo(OR )2(NAr)(=CHR) [C2Ciim]Cl-AlCl3 Ring-opening cross-metathesis of norbomene with allyltrimethylsilylsilane product extracted with hexane conversion after one hour at RT ca. 80%, selectivity for the disilylated product ca. 75%. [24]... 

Scheme 7.5 Ring-opening polymerisation metathesis of norbomene...

These complexes are suitable for the ring-opening metathesis polymerization of functionalized norbomenes in water,148 as well as ring-closure reactions via ethylene elimination.149 The versatility of these catalysts has given rise to extensive applications in organic synthesis,150151 including, for example, amino acid derivatives.152... 

PiccineUi [5] used (tricyclopentylphosphine)dichloro(3-methyl-butenylidene), (VI), or related cyclic derivatives, (VII), to prepared anti-fog agents, (Vlll), by coupling 2-norbomene and aUyl-terminated ohgomeric ethylene oxide using ring opening metathesis polymerization as illustrated in (VIII) below. 

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