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Showing papers on "Norbornadiene published in 1987"


Journal ArticleDOI
TL;DR: By catalysis of AIBN, tosyl cyanide adds in a regio-and stereoselective manner to unsaturated hydrocarbons, including alkenes, dienes and 1-hexyne.

72 citations


Journal ArticleDOI
TL;DR: Sulfuration par S 8 des norbornene, dicyclopentadiene, isodicyclopsine, norbornadiene and sesquinorbornene: obtention dans la plupart des cases de trithiolannes-1, 2,3 eventuellement avec des pentathiepannes -1,2,3,4,5.
Abstract: Sulfuration par S 8 des norbornene, dicyclopentadiene, isodicyclopentadiene, norbornadiene, dihydro-1,4 methano-1,4naphtalene, aryl-2 norbornenes et sesquinorbornene: obtention dans la plupart des cas de trithiolannes-1,2,3 eventuellement avec des pentathiepannes-1,2,3,4,5. Mecanismes

65 citations



Journal ArticleDOI
TL;DR: O- β -oxoalkyl-N,N-dialkyl carbamates are obtained, in one-step, by reaction of α -ethynyl alcohols, carbon dioxide and diethylamine, piperidine or pyrrolidine as discussed by the authors.

51 citations



Journal ArticleDOI
TL;DR: Synthese a partir de la reaction de Diels Alder entre la benzoquinone-1,4 and le cyclopentadiene-1.3 as discussed by the authors.
Abstract: Synthese a partir de la reaction de Diels Alder entre la benzoquinone-1,4 et le cyclopentadiene-1,3

49 citations


Journal ArticleDOI
TL;DR: In this article, the reduction of a series of Pd(II) complexes has been studied by electrochemistry and spectroscopy, yielding the first stable Pd (I)..pi.. radicals.
Abstract: The reduction of a series of Pd(II) complexes has been studied by electrochemistry and spectroscopy. Neutral Pd(I) radicals may be obtained from the reduction of (eta/sup 5/-C/sub 5/Ph/sub 5/)Pd(eta/sup 4/-diolefin) cations, where diolefin = 1,5-cyclotadiene, norbornadiene, or dibenzocyclooctatetraene. The one-electron processes are diffusion-controlled and highly reversible, yielding the first stable Pd(I) ..pi.. radicals. The dibenzocyclooctatetraene derivative is isolable. These complexes undergo radical reaction with water, chlorinated hydrocarbons, and peroxides to give ..pi..,sigma-Pd(II) complexes identical with those obtained by direct attack of nucleophiles on the starting Pd(II) cationic complexes. Reversible oxidation of (eta/sup 5/-C/sub 5/Ph/sub 5/)Pd(eta/sup 4/-diolefin) cations demonstrates the existence of formal Pd(III) complexes in these systems. The pentaphenylcyclopentadienyl ligand gives kinetic stabilization to both Pd(I) and Pd(III), compared to the unsubstituted cyclopentadienyl analogues.

44 citations



Journal ArticleDOI
TL;DR: The chloro complexes 1-5 ionise readily in methanol containing NH 4 PF 6 and a donor ligand to give a range of new cations as hexafluorophosphate salts as discussed by the authors.

37 citations



Journal ArticleDOI
TL;DR: Sterically protected fused 1,2,3thiadiazole and 1, 2,3-selenadiazoles were heated with molten sulfur resulting in a ready formation of fused cyclopolysulfides, the photolysis of which in the presence of olefins afforded the cycloadducts via the initially formed 1 2-dithione and 1 2 -selenoxothione as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, the bromo(alkylidyne)tungsten complex [W(CR) Br(CO)4] and the salts Na2[7,8-C2B9H9R′2]-R′= Me or H.
Abstract: Reactions between the bromo(alkylidyne)tungsten complex [W(CR) Br(CO)4](R = C6H4Me-4) and the salts Na2[7,8-C2B9H9R′2](R′= Me or H), followed by treatment with [N(PPh3)2]Cl afford the compounds [N(PPh3)2][W(CR)(CO)2(η5-C2B9H9R′2)](1a, R′= Me; 1b, R′= H). The salt [NEt4][W(CMe)(CO)2(η5-C2B9H9Me2)](1c) was prepared from [W(CMe)Br(CO)4] and Tl2[7,8-C2B9H9Me2], with subsequent addition of [NEt4]Cl. Treatment of (1a) or (1b) with [AuCl(PPh3)], in the presence of TIPF6 yields the gold–tungsten complexes [AuW(µ-CR)(CO)2( PPh3)(η5-C2B9H9R′2)](2a, R′= Me; 2b, R′= H). Similarly, (1c) with [AuCl( PPh3)] affords [AuW(µ-CMe)(CO)2( PPh3)(η5-C2B9H9Me2)](2c). The structure of (2a) has been established by X-ray diffraction. The Au–W bond [2.780(8)A] is asymmetrically bridged by the CC6H4Me-4 group [µ-C–Au 2.19(3), µ-C–W 1.88(3)A]. Treatment of [AuCl(tht)](tht = tetrahydrothiophene) with (1a) gives the salt [N( PPh3)2][AuW2(µ-CR)2(CO)4(η5-C2B9H9Me2)2](3). The rhodium–tungsten compound [RhW(µ-CR)(CO)2(PPh3)2(η5-C2B9H9Me2)](4a) has been prepared by two routes: from the reaction between (1a) and [RhCl(PPh3)3] or from (1a) and [Rh(PPh3)2(cod)][PF6](cod = cyclo-octa-1,5-diene). The latter with (1b) yields [RhW(µ-CR)(CO)2(PPh3)2(η5-C2B9H11)](4b). Compounds (1a) and (1b) react with [Rh(PPh3)2(nbd)][PF6][nbd = norbornadiene (bicyclo[2.2.1] hepta-2,5-diene)] to give the complexes [RhW(µ-CR(CO)2(PPh3)2{η5-C2B9(C7H9)H8R′2}][5a,R′= Me; 5b, (two isomers), R′= H]. The structures of (4a) and (5a) have been established by X-ray diffraction. Both molecules have Y-shaped WRhP2 cores with the Rh–W bonds [4a, 2.681 (l), 5a, 2.662(2)A] bridged by CC6H4Me-4 groups [4a, µ-C–Rh 2.068(5), µ-C–W 1.880(6); 5a, µ-C-Rh 2.12(2), µ-C–W 1.84(2)A], and semibridged by a CO ligand [W–C-O, 4a, 160.2(5); 5a, 156( 1 )°] In (4a), the tungsten atom is ligated by a terminal CO group and the η5-C2B9H9Me2 cage. In (5a), the tungsten also carries a terminal CO group but the carbaborane ligand has a C7H9[nortricyclene (tricyclo[2.2.1.02,6] heptane)] fragment attached to the unique boron atom in the open face of the cage. Thus in the formation of (5a) an unprecedented hydroboration reaction has occurred, a cage B–H bond having added to the norbornadiene ligand with concomitant C–C bond formation. In contrast, treatment of the norbornadiene-containing salt (Rh(dppe)(nbd)[PF6](dppe = Ph2PCH2CH2PPh2) with (1a) gives [RhW(µ-CR)(CO)2(dppe)(η5-C2B9H9Me2)](4c). Reactions of (4a) with PEt3, PMe2Ph, dppe, and CO are reported. Examination of the 13C-{1H} and 31P-{1H} n.m.r. spectra of the complexes (4) and (5) reveal that they undergo dynamic behaviour in solution and possible mechanisms are described and discussed.

Journal ArticleDOI
TL;DR: The complexes PtR 2 (diene) (R = C 6 F 5 or p -HC 6 F 4 ) and hexa-1,5-diene (hex) have been prepared by the organolithium route.

Journal ArticleDOI
TL;DR: The advances achieved in recent years in the synthesis of polycyclic hydrocarbons, including those containing functional substituents, from norbornadiene and its derivatives using metal complex catalysts are surveyed in this paper.
Abstract: The advances achieved in recent years in the synthesis of polycyclic hydrocarbons, including those containing functional substituents, from norbornadiene and its derivatives using metal complex catalysts are surveyed. The homo- and codimerisation reactions of norbornadienes with olefins, dienes, and acetylenes, involving the [2π + 2π] -, [2π + 2π + 2π] -, and [4π + 4π] -addition under the influence of transition metal complexes are examined. Data on the synthesis of norbornadiene trimers as well as the physicochemical and spectroscopic characteristics of a whole series of unique hydrocarbons are presented. The mechanisms of the reactions indicated are discussed. The bibliography includes 173 references.

Journal ArticleDOI
TL;DR: In this paper, the quantum yields for norbornadiene(N)→quadricyclane(Q) and Q→N isomerization were determined in acetonitrile using several substituted benzophenones (BPs) as triplet sensitizers.
Abstract: The quantum yields for norbornadiene(N)→quadricyclane(Q) and Q→N isomerization were determined in acetonitrile using several substituted benzophenones (BPs) as triplet sensitizers. For the N→Q isomerization, BPs with electron-donating substituents exhibited higher quantum efficiency (0.4–0.6) than BPs with electronaccepting substituents. The quantum yields for Q→N isomerization increased with electron-accepting ability of the substituents on BPs, but were lower than 0.1. The rate constants for quenching of triplet BPs by N and Q were also determined in acetonitrile by means of laser flash photolysis. The rate constants for N were not dependent on the triplet energies (ET) of BPs but dependent on electronic properties of the substituents on BPs. On the contrary, those for Q increased with decreasing ET of BPs and with increasing Hammett’s σ constants of the substituents of BPs. Based on these observations an addition-elimination process is proposed for the N→Q isomerization, and an electron transfer proces...

Journal ArticleDOI
TL;DR: In this paper, the structures of norbornane, norbornene and 7-oxanorbornane were completely determined by analytical gradient techniques in conjunction with ab initio Hartree-Fock molecular orbital theory.
Abstract: The structures of norbornane, norbornene, norbornadiene, 7-oxanorbornane, and 7-thianorbornane were completely determined by analytical gradient techniques in conjunction with ab initio Hartree—Fock molecular orbital theory. Geometric details obtained at the minimal STO-3G and split valence 3–21G levels of theory, are compared with data available from various experimental studies using both microwave and electron diffraction spectroscopy. Variations in the geometric parameters which ensue from introduction of the functional groups into the bicyclo [2.2.1] heptane skeleton are discussed in terms of perturbative molecular orbital (PMO) theory.

Journal ArticleDOI
TL;DR: In this paper, the photocatalytic activity of di-2-pyridyl ketone (dpk) complexes has been characterized by analytical and spectroscopic data.
Abstract: Copper(I) complexes of di-2-pyridyl ketone (dpk), [Cu(PPh3)2(dpk)]NO3, [Cu2l2(PPh3)2(dpk)], and [Cu4I4(dpk)3], have been synthesized. The compounds were characterized by analytical and spectroscopic data. Their photocatalytic activity for the solar energy storage reaction norbornadiene (bicyclo[2.2.1]hepta-2,5-diene) to quadricyclane (tetracyclo[3.2.0.0.2.7.04,6]heptane) has been studied. The species [Cu(dpk)2]+, generated in situ from [Cu(CH3CN)4]+ and dpk, was found to be a stable photocatalyst at λ > 320 nm.


Journal ArticleDOI
TL;DR: Syntheses of polymers containing Pendant Norbornadiene derivatives by a Phase Transfer Catalysis and their Photochemical Valence Isomerization are discussed in detail in this article.
Abstract: Syntheses of Polymers Containing Pendant Norbornadiene Derivatives by a Phase Transfer Catalysis and Their Photochemical Valence Isomerization

Journal ArticleDOI
TL;DR: In this paper, a bimetallic complex with carbon monoxide was formulated as [(OC)4Fe(µ-dppm)Mo(CO)5], which was not isolated.
Abstract: Treatment of [Fe2(CO)9] with dppm (Ph2PCH2PPh2) in tetrahydrofuran gave [Fe(CO)4(dppm-P)] and other products. Treatment of [Fe(CO)4(dppm-P)] with [Mn(CO)5Br] gave [(OC)4Fe(µ-dppm)-Mn(CO)3Br] in 58% yield. This bimetallic complex reacted reversibly with carbon monoxide, breaking the metal–metal bond to give [(OC)4Fe(µ-dppm)Mn(CO)4Br]. Treatment of [Fe(CO)4(dppm-P)] with [Mo(CO)4(nbd)]{nbd = norbornadiene (bicyclo[2.2.1]hepta-2,5-diene)} gave [(OC)4Fe(µ-dppm)Mo(CO)4] in 47% yield. This bimetallic complex reacts with carbon monoxide to give a complex, formulated as [(OC)4Fe(µ-dppm)Mo(CO)5], which was not isolated. Analogous reactions with the diphosphine CH2C(PPh2)2 are described. Crystals of [(OC)4Fe(µ-dppm)-Mo(CO)4] are tetragonal, space group I41cd(no. 110), with a= 1 853.1(4), c= 4 106.8(9) pm, and Z= 16; final R= 0.0633 for 3 357 observed reflections. The structure shows that there is a metal–metal bond [Fe–Mo 302.4(5) pm] formulated as a donor → acceptor bond, viz. Fe → Mo.

Journal ArticleDOI
TL;DR: In this paper, the reaction of fused 1, 2, 3-selenadiazole with 4-t-butyl-1, 2-3-selenium atom yielded [2+4] cycloadducts in the presence of olefins.

Journal ArticleDOI
TL;DR: In this article, the authors describe a catalyseur d'hydrogenation asymetrique contenant un rhenium chiral dans un squelette diphosphane chelatant.
Abstract: Description d'un catalyseur d'hydrogenation asymetrique contenant un rhenium chiral dans un squelette diphosphane chelatant. Production de l'exces enantiomerique le plus eleve jamais obtenu avec des systemes au rhodium

Journal ArticleDOI
TL;DR: In this article, it was shown that the cyclodimerization of NBD CF3COO)4 with dichloromethane at room temperature is regulated by the ligand environment of the rhodium atom.

Journal ArticleDOI
N. Auner1
TL;DR: In this article, the monosilacyclobutanes were cyclodimerized to 2,4-di- neopentyl-1,3-disilacy clobutane and showed that the cycloadducts indicate a multistep-pathway, probably with participation of lithiated species, whereas the [2,+ 2]- and [2 + 2+ 2 + 2]-cycloadduct reactions confirm that the silaethenes 1 and 2 are formed as reactive intermediates.

Journal ArticleDOI
TL;DR: Etude de l'influence de different photosensibilisants (cetones and quinones) and de la longueur d'onde sur le rendement quantique en quadricyclane and sur l'efficacite de la conversion d'energie. as discussed by the authors.
Abstract: Etude de l'influence de differents photosensibilisants (cetones et quinones) et de la longueur d'onde sur le rendement quantique en quadricyclane et sur l'efficacite de la conversion d'energie. La formation d'un polymere est vue. Pour supprimer l'apparition de ce sous-produit, on ajoute une substance phenolique dans le norbornadiene

Journal ArticleDOI
TL;DR: In this paper, the ground and cationic states of benzene, norbornadiene, and barrelene were computed using Koopman's one-electron process type, and the order of states is close to that of the SCF double zeta ground state calculations.

Journal ArticleDOI
TL;DR: Synthese et caracterisation de Pt(OTeF 5 ) 2 (NBD) et Pd(OTEF 5 ] 2 (C 6 H 5 CN) 2 Structure moleculaire du 1er
Abstract: Synthese et caracterisation de Pt(OTeF 5 ) 2 (NBD) et Pd(OTeF 5 ) 2 (C 6 H 5 CN) 2 Structure moleculaire du 1er

Journal ArticleDOI
TL;DR: Bis(dimethylamino), bis(diethylamino)-, and chloro(diisopropylamino)phosphenium ions ( 1a,c, respectively) react cleanly with norbornadiene ( N ) to yield the homo-1,4-cycloadducts ( 2a, c ).

Journal ArticleDOI
TL;DR: Polycyclic bisadducts are formed in good yields from the addition of methyl propiolate to norbornadiene and quadricyclane under high pressure via sequential (π2 + π2+ π 2) and (π 2 + σ2+π�2) processes.

Journal ArticleDOI
TL;DR: In this paper, the effect of aryl substituents on the thermal reversion was investigated and it was shown that spin delocalization and polar effect equally contribute to the stabilization of the transition state.
Abstract: 2-Arylhexachloronorbornadiene undergoes photoisomerization to the corresponding quadricyclane, which returns back to the norbornadiene upon heating without catalyst Effect of aryl substituents on the thermal reversion suggests that both spin delocalization and polar effect equally contribute to the stabilization of the transition state