Showing papers on "Norbornene published in 1980"
TL;DR: Optically active norbornyl and 1-phenylethyl alcohols and bromides were obtained, respectively, from either norbornene and styrene with trichlorosilane catalyzed by a chiral ferrocenylphosphine-palladium complex followed by treatment with potassium fluoride.
123 citations
TL;DR: In this article, the exo addition of electrophiles on norbornene systems is analyzed in this context, and the geometry of norbornenes 1 and norbornadiene 2 is fully optimized by ab initio calculations.
51 citations
Patent•
18 Sep 1980TL;DR: A polymeric composition of matter formed by ring opening polymerization using a metathesis catalyst comprising bound antioxidant which is a reaction product of a norbornene-type monomer as discussed by the authors.
Abstract: A polymeric composition of matter formed by ring opening polymerization using a metathesis catalyst comprising bound antioxidant which is a reaction product of a norbornene-type monomer and a norbornenyl phenolic antioxidant.
23 citations
TL;DR: In this paper, N-phenyl-5-norbornene-2,3-dicarboximide was converted to exo-isomers under various reaction conditions.
Abstract: ENDO isomers of N-phenyl-5-norbornene-2,3-dicarboximide was converted to exo-isomers below retro-Diels-Alder temperature under various reaction conditions The exo-endo yield ratio was studied by NMR and the 1H and 13C NMR chemical shifts of the isomers are reported While no intermediate could be isolated using several different radical trapping agents, the results show that 7,5 proton chemical shift is a possible isomerization mechanism
22 citations
TL;DR: In this paper, a review of the determination of various types of pair sequence in ring-opened polymers and copolymers of cycloalkenes is presented, and four types are discussed: (1), cc, ct, tc, tt double bond pairs; (2) m and r ring-configurational dyads in norbornene polymers; (3) TH, TT, HH, HT dyads (H = head, T = tail) in polymers of 5-substituted norbornenes; and (4) M
22 citations
20 citations
TL;DR: In this article, it was shown that the 3-ketone triplet with the quadricyclene gives 1: 1-adducts with endo-orientation.
18 citations
TL;DR: The reaction of norbornene was used as a mechanistic probe to elucidate the effect of catalyst and temperature on liquid phase fluorinatioh with xenon difluoride as discussed by the authors.
Abstract: The reaction of norbornene was used as a mechanistic probe to elucidate the effect of catalyst (HF, HF–pyridine, BF3, BF3–etherate, and pentafluorothiophenol) and temperature (from −61 °C to 25 °C) on liquid phase fluorinatioh with xenon difluoride, resulting in the formation of seven products, depending on the reaction conditions : fluoronortricyclane, 2-endo-5-exo-difluoronorbornane, 2-exo-7-anti-difluoronorbornane, 2-endo-5-exo-difluoronorbornane, 2-exo-5-exo-difluoronorbornane, 2-exo-3-exo-difluoronorbornane, and 2-exo-7-syn-difluoronorbornane. The catalyst has a significant effect on the reaction pathways, boron trifluoride etherate favouring the formation of 2-endo-5-exo- and 2-exo-5-exo-difluoronorbornane, while pentafluorothiophenol favoured the formation of fluoronortricyclane. The catalyst and temperature has much less effect on the reaction pathways in the case of norbornadiene, four products being formed: fluoronortricyclane, 3-endo-5-exo-difluoronortricyclane, 3-exo-5-exo-difluoronortricyclan...
14 citations
TL;DR: In this article, Thiono and Esters showed that cycloadducts with Dithionooxalates react as a 2π-component with typical dienes (e.g. 2,3-dimethylbutadiene or cylopentadiene) as well as with the strained σ-bonds of quadricyclane to form cycloaddition products.
12 citations
TL;DR: Free radicals, believed to be dithiazolidine derivatives, have been shown to be formed readily from tetrasulphur dinitride and norbornene compounds in organic solvents: it is also possible to form these radicals from other sulphur-nitrogen compounds and from other types of olefins as mentioned in this paper.
Abstract: Free radicals, believed to be dithiazolidine derivatives, have been shown to be formed readily from tetrasulphur dinitride and norbornene compounds in organic solvents: it is also possible to form these radicals from other sulphur–nitrogen compounds and from other types of olefins. A feature of the e.s.r. spectra is the resolution at low temperatures of small splittings caused by longrange coupling to hydrogen nuclei. The hyperfine coupling constants are solvent and temperature dependent. The latter effect is attributed to out-of-plane vibrations of the —S—[graphic omitted]—S— group of the dithiazolidine ring. At low temperatures the radicals dimerise reversibly and the thermodynamic parameters have been evaluated for several different types of olefin.
10 citations
TL;DR: In this article, the authors showed that N-phenylsulfonyl)-benzohydrazonoyl chloride in refluxing toluene generated 1,3-dipolar cycloadducts with ethyl ( 4a ) and methyl acrylate ( 4b ), acrylonitrile ( 4c ), styrene ( 4d ), norbornene ( 4e ), and norbornadiene (4f ).
TL;DR: In this article, the relative rate constants for the Birch reduction (Li/liq. NH3/t-butyl alcohol) of norbornadiene (1), 1,4-dihydronaphthalene (3), 9-(1-methylethylidene)-1, 4-dhydro-1,4methanonaphthylene(5), 1.4- dihydro- 1, 4 -epoxynaphthalenes (7), lithium benzoate, α-methylstyrene,
Abstract: Relative rate constants for the Birch reduction (Li/liq. NH3/t-butyl alcohol) of norbornadiene (1),1,4-dihydro-1,4-methanonaphthalene (3), 9-(1-methylethylidene)-1,4-dihydro-1,4-methanonaphthalene(5), 1,4- dihydro-1,4-epoxynaphthalene (7), lithium benzoate, α-methylstyrene, and the hexahydrobenzenomethanoanthracene(20a), were obtained and compared with that obtained for the reduction of norbornene from an earlier study. Compounds (1), (3) and (5) were some 105 times more readily reduced than norbornene. These results are best explained in terms of the presence of through-space interactions operating between the two lowest unoccupied molecular orbitals in these molecules. The Birch reduction of (7) gave mainly 1,4-dihydronaphthalene (17).A mechanism for this reaction is presented.
TL;DR: The kinetic parameters for the polymerisation reaction of norbornene with RuCl3•3H2O, and RuCl2(PΦ3)3 using homogeneous catalysis have been determined in this paper.
Abstract: The kinetic parameters for the polymerisation reaction of norbornene with RuCl3•3H2O, and RuCl2(PΦ3)3 using homogeneous catalysis have been determined (first-order with respect to two initiators, zero-order with respect to the monomer with RuCl3•3H2O, and variable order with RuCl2(PΦ3)3: Ea 6.2 kcal/mol for RuCl2(PΦ3)3 and 22.8 for RuCl3•3H2O) and leads us to propose different reaction mechanisms for the polymerisation starting from the two initiators, at least for the initiation step. With RuCl2(PΦ3)3 the slow step of the reaction is the metathesis whereas with RuCl3•3H2O the slow step is a ligand exchange at the initiator involving solvent (alcohol) by a dissociative or associative mechanism. This slow step is confirmed by a study of varying alcohol concentration and initiator aging. [Journal translation]
TL;DR: The proton spectra of exo and endo-3-thiatricyclo[4.2.1.02,5]non-7-ene 3,3-dioxide have been analyzed and completely assigned as mentioned in this paper.
Abstract: The proton spectra of exo- and endo-3-thiatricyclo[4.2.1.02,5]non-7-ene 3,3-dioxide have been analysed and completely assigned. Considerations of coupling constants indicate that the thietane ring is nonplanar and that the norbornene residue is significantly distorted from the geometry of norbornene itself. The sulfone group induces significant changes in the shielding of the proximate olefinic proton in the endo isomer and the bridge protons in the exo isomer. These shifts appear to be the result of the electrostatic effects and effects associated with the diagmagnetic anisotropy of the sulfone group.
TL;DR: In this paper, the partial alkylation of diborane with norbornene and cyclopentene was carried out in THF and the equilibrium distribution of the borane derivatives was determined.
Abstract: Systematic studies of the partial alkylation of diborane with norbornene and cyclopentene were carried out in THF and the equilibrium distribution of the borane derivatives was determined. Di-exo-norbornylborane was obtained in 71% yield with no mono-exo-norbornylborane as a by-product, under the conditions: initial ratio of norbornene to borane 2 : 1, temperature 0 °C and reaction time 1 h. Mono-exo-norbornylborane was obtained in 72–75% yield under the conditions: initial ratio of norbornene to borane 1 : 1, temperature 25 °C, and reaction time 48 h. In the dialkylborane [R2BH]2, norbornene and cyclopentene exhibit very different behavior during the course of equilibration reaction.