Showing papers on "Norbornene published in 1986"

Titanacyclobutanes derived from strained, cyclic olefins: the living polymerization of norbornene

Abstract: Mecanisme de la polymerisation par ouverture de cycle, par metathese en presence de ces derives

Preparative metallation of norbornene and norbornadiene

Abstract: Norbornene and norbornadiene have been successfully metallated with the complex BuLi · t-BuOK in tetrahydrofuran and a number of derivatives prepared by reaction of the metallic intermediates with electrophilic reagents.

Anionic homoaromaticity: a gas-phase experimental study

Abstract: Les acidites en phase gazeuse de quelques alcenes et dienes mono- et bicycliques sont mesurees dans une etude modele de l'homoaromaticite anionique

Cis/trans reactivity ratios in the ring‐opening polymerization of bicyclo[2.2.1]hept‐2‐ene; the nature of the propagating species in olefin metathesis

Abstract: The olefinic regions of the 13C NMR spectra of numerous ring-opened polymers of bicyclo[2.2.1]hept-2-ene (norbornene) having cis double bond contents in the range σc = 0,32–0,86, have been analysed in detail. At least six peaks are resolved corresponding to olefinic carbons defined in terms of the double bond sequences tcc, tct + ccc, cct, ttc, ctc + ttt, ctt; for polymers of intermediate cis-content tct and ccc are also resolved. The relative intensities of the cis-centred triads may be accounted for in terms of a single parameter, rc, derived from the observed dyad probabilities. The relative intensities of the trans-centred triads, however, show that at higher cis-contents, the sequence cttc occurs with greater frequency than expected, requiring interpretation in terms of two trans-parameters, rtt and rtc. These results show that the generally noted feature of cis/trans blockiness at moderately high cis-content is sometimes associated with the presence of three kinetically distinct propagating species rather than two. The first is postulated to be the highly cis-directing olefin-metal-carbene complex 4 in which the previously formed cis double bond remains coordinated to the metal centre; this may have both chiral and achiral forms. The second and third are postulated to be isomeric species formed by decoordination of the previously formed trans double bond from the metal centre but in which the initial ligand geometry is governed by the nature of the penultimate double bond: 3tc and 3tt are postulated to have permanent ligands with square pyramidal and octahedral symmetry, respectively. It is shown how the present results and those from related work may be rationalised in terms of this hypothesis.

Polycycloolefins resistant to solvents

Abstract: of the Disclosure Thermoset polycycloolefins are obtained by polymerzing at an elevated temperature a cycloolefin containing at least one norbornene group in the presence of a metathesis catalyst system and also in the presence of an effective amount of a polyfunctional cycloolefin crosslinker containing at least one norbornene group, but preferably two or more, with two or more unsaturated sites, preferably two or more double bonds.

Elektrophile Alkylierungen von Norbornen – Synthese 7‐substituierter Norbornene

Abstract: Die Lewis-Saure-katalysierte Addition SN1-reaktiver Alkylhalogenide 2 an Norbornen liefert syn-7-Alkyl-exo-2-halogennorbornane 3 neben geringen Mengen der anti-Isomeren 9. Bei der Behandlung von 3 mit Kalium-tert-butoxid erhalt man die syn-7-substituierten Norbornene 4, die zu all-cis-1,2,3-trisubstituierten Cyclopentanen oxidiert werden konnen.

Ethylene copolymer rubber

Abstract: PURPOSE: To obtain the titled rubber highly excellent in form retentivity, also outstanding in extrusion processability, curing rate, etc., by copolymerization between ethylene, α-olefin, 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2- norbornene (VNB). CONSTITUTION: For example, in a hydrocarbon solvent, a random co polymerization between ethylene, 3W10C α-olefin, ENB and VNB is carried out in the presence of a catalyst comprising soluble vanadium compound and organoaluminum compound to obtain the objective rubber having the following characteristics; 1. molar ratio of ethylene/α-olefin ... 50/50W95/5, 2. molar ratio of ENB/VNB ... 1/1W45/1, 3. iodine value ... 2W50, 4. intrinsic viscosity [η]determined in the form of decalin solution at 135°C ... 0.7W6.0dl/g, 5. Q-value (weight-average molecular weight/number-average molecular weight) ... ≥6. COPYRIGHT: (C)1988,JPO&Japio

Molded article of crosslinked polymer, production thereof and combination of reactive solutions

Abstract: PURPOSE: To produce a molded article having excellent properties free from residual norbornene derivative in a polymer, by polymerizing a monomer mixture of a metathetic polymerizable cycloalkene and a pyridyl group-containing norbornene derivative in the presence of a catalyst. CONSTITUTION: A monomer mixture consisting of 90W99.9mol% metathetic polymerizable cycloalkene (e.g. 5-ethylidene norbornene, 5-polymerizable cycloalkene (e.g. 5-ethylidene norbornene, 5-methoxycarbonylnorbornene, etc.) containing ≥30mol% dicyclopentadiene and 10W0.1mol% pyridyl group- containing norbornene derivative [e.g. 5-(4-pyridyl)norbornene, etc.] is polymerized in the presence of a metathetic polymerization catalyst system (e.g. catalyst consisting of tungsten compound, Lewis base and tetraalkyltin, etc.) to give the aimed molded article. A combination of (A) a solution of a cyclic olefin compound containing a catalyst of metathetic polymerization catalyst system and (B) a solution of a cyclic olefin compound containing an activator for the catalyst system is used as a reactive solution. In the cyclic olefins in the solutions, both the solutions are blended to give a composition equal to that of the monomer mixture. COPYRIGHT: (C)1988,JPO&Japio

Characterization of ethylene homo- and copolymers

Abstract: For the estimation of molecular mass distribution and average molecular masses of (norbornene ethylene) copolymers a size exclusion chromatography method is described. The validity of the universal calibration function of Benoit et al. based on polystyrene molecular mass standards was confirmed by comparing with the number average molecular masses obtained by osmometry. The constants of the Mark-Houwink equation are a = 0.535, K = 1.00·10−1 (Xylene, 90 °C) and a=0.589, K=4.93·10−2 (diethylbenzene, 120°C,[η] in cm3g−1).

Crosslinked polymer molding, its production and combination of reactive solutions

Abstract: PURPOSE: To obtain the title molding excellent in heat resistance and suitable as a large molding such as an automobile member, by simultaneously performing polymerization and molding of a monomer feed comprising a specified adduct or its mixture with other metathesis-polymerizable monomers in the presence of a metathesis polymerization catalyst system. CONSTITUTION: A monomer feed (A) comprising a 1:1 adduct of formulas II and III, formed by performing a Diels-Alder reaction of 3a,4,7,7a- tetrahydroindene (a) of formula I with cyclopentadiene (b) or its mixture with 0W95mol% at least one metathesis-polymerizable monomer selected from among a cycloalkene except cyclohexene, a compound having at least a norbornene skeleton of formula IV (wherein the dotted valence bonds may be combined together through other atoms to form cyclic structures, etc.) is bulk-polymerized in a mold in the presence of a metathesis polymerization catalyst system (B) comprising a base catalyst component (e.g., WCl 6 ) and an activator component [e.g., (C 2 H 5 ) 2 AlCl] to perform polymerization and molding simultaneously. COPYRIGHT: (C)1988,JPO&Japio

Nitratomercuriation of alkenes

Abstract: Alkenes react rapidly and reversibly with mercury(II) nitrate to form β-nitratoalkylmercury(II) nitrates which undergo brominolysis to give β-bromoalkyl nitrates.

Reactions of sulfonyl substituted furoxans with olefins

Abstract: Selon les substituants, on obtient des biisoxazoline-2yles-3,3' ou des acetohydroximoyl-3 isoxazolines-2

Studies of heterocyclic compounds. 8. The synthesis and some reactions of 4-bromoimidazole-5-sulfonyl derivatives

Abstract: Synthese de chlorure de bromo-4 imidazolesulfonyle-5 a partir de bromo-4 imidazole, d'acide chlorosulfurique et de chlorure de thionyle; a partir de ce chlorure, synthese d'azide, d'hydrazide et d'amides

Homo-Coupling Reactions of Norbornene Derivatives Catalyzed by Ni-Complexes

Abstract: The homo-coupling reaction of norbornene (NB) and dicyclopentadiene (DCP) was investigated by using NiX2(R 3P)2-NaBH4 catalyst. This Ni-catalyzed reaction of NB gave homocoupling products, exo-2-(2'-norbornenyl)norbornane (1), bi-2, 2-norbornylidene (2) and exo-2-(4'-methylenecyclohex-1'-en-3'-yl) norbornane (3). Their product distributions depended on the ligand and the halogen bound to Ni-complex as well as the reaction temperature. When the NiCl2(Ph3P)2-NaBH4 system was employed as catalyst, 1 and 2 were formed in preference to 3. It was found that 2 was derived from Ni-catalyzed isomerization of 1, but not the direct coupling of NB. The reaction of NB catalyzed by NiBr2(Bu3P)2, instead of NiCl2(Ph3P)2, afforded the coupling product 3 in good yield. On the other hand, NiX2(R3P)2-NaBH4 catalyzed coupling of endo- and exo-DCP's gave somewhat different results from those of NB.

Rubber composition and additive therefor

Abstract: PURPOSE:To obtain a rubber composition having remarkably improved cut resistance and chipping resistance, by compounding a rubber with a thermally polymerized cyclopentadiene-type petroleum resin having specified concentration ratio of norbornene ring double bond to cyclopentene ring double bond. CONSTITUTION:100pts.(wt.) of a diene polymer (e.g. natural rubber, poly butadiene, etc.) is compounded with 5-40pts., preferably 5-20pts. of a thermally polymerized cyclopentadiene-type petroleum resin wherein the concentration ratio of the norbornene ring double bond to the cyclopentene ring double bond is <=0.4 and the ratio of the copolymerizable olefinic hydrocarbon to cyclopentadiene is <=10wt%.