121-46-0Relevant articles and documents
SURFACE PHOTOCHEMISTRY: SEMICONDUCTOR PHOTOINDUCED VALENCE ISOMERIZATION OF QUADRICYCLANE TO NORBORNADIENE
Draper, Anthony M.,Mayo, Paul de
, p. 6157 - 6160 (1986)
Contrary to a recent report, the valence isomerization via a radical cation, of quadricyclane to norbornadiene on the surface of illuminated CdS and ZnO is described.
Iridium-Catalyzed Asymmetric Hydroalkenylation of Norbornene Derivatives
Sun, Xin,Bai, Xiao-Yan,Li, An-Zhen,Li, Bi-Jie
, p. 2182 - 2187 (2021)
Transition-metal-catalyzed asymmetric hydroalkenylation of alkenes provides an atom-economical method to build molecular complexity from easily available materials. Herein we report an iridium-catalyzed asymmetric hydroalkenylation of unconjugated alkenes with acrylamides and acrylates. The catalytic hydroalkenylation of norbornene derivatives occurred to form products with allylic stereocenters with high chemo-, regio-, and stereoselectivities. DFT calculations revealed that the migratory insertion is irreversible and the enantiodetermination step.
Structure-Reactivity Factors for Exciplex Isomerization of Quadricyclene and Related Compounds
Jones, Guilford,Chiang, Sheau-Hwa,Becker, William G.,Greenberg, Don P.
, p. 681 - 683 (1980)
The quadricyclenes (1) and (3) are equally effective in exciplex isomerization although other cage hydrocarbons do not undergo efficient reaction when sensitized by aromatic fluorophores; irradiation of charge-transfer complexes of (1) and (3) and electron-deficient alkenes results in efficient valence but not geometrical isomerization.
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Wiberg,Connon
, p. 5411,5412 (1976)
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THERMAL ISOMERIZATION OF QUADRICYCLANE TO NORBORNADIENE CATALYZED BY COPPER(II) AND TIN(II) SALTS.
Fife,Morse,Moore
, p. 7404 - 7407 (1983)
Copper(II) salts and tin(II) chloride show exceptional heterogeneous catalytic behavior in converting quadricyclane to norbornadiene in benzene. The heterogeneous catalysis mechanism is described by the adsorption of quadricyclane on the salt surface by a combination of a one-site and a two-site coordination. The two-site-coordination process results in the formation of C//7H//8X//2 (X equals Cl or Br) as a side product when CuCl//2 or CuBr//2 are used as catalysts. The rate constant for the disappearance of quadricyclane is much greater when CuCl//2 or CuBr//2 are used as catalysts. The rate constant for the disappearance of quadricyclane is much greater when CuCl//2 or CuBr//2 (approximately 10** minus **2 min** minus **1 cm** minus **2) is used than when CuSO//4 (approximately 10** minus **4 min** minus **1 cm** minus **2) is used.
PHOTOGENERATED CATALYSIS BY TRANSITION-METAL COMPLEXES. PHOTOACCELERATION OF THE VALENCE ISOMERIZATION OF QUADRICYCLENE TO NORBORNADIENE IN THE PRESENCE OF PdCl2( eta 4-NORBORNADIENE).
Borsub,Kutal
, p. 4826 - 4828 (1984)
Light accelerates the rate at which PdCl//2( eta **4-NBD) (1) catalyzes the valence isomerization of quadricyclene (Q) to norbornadiene (NBD). The observed quantum yield, defined as (mol of NBD produced/mol of photons absorbed), can exceed 10**2 and is dependent upon Q concentration, light intensity, and solvent. Several lines of evidence are consistent with the intermediacy of radical species in the isomerization process. The results are discussed in terms of a redox-chain mechanism in which the initiation step involves reductive quenching of a Pd-to-NBD charge-transfer excited state of 1 by Q.
Chemistry of Weakly Solvated Lanthanide-Metal Cations. Synthesis, Characterization, and Catalytic Chemistry of x
Thomas, Richard R.,Chebolu, Venkatasuryanarayana,Sen, Ayusman
, p. 4096 - 4103 (1986)
The title compound, x, 1, was synthesized by the NOBF4 oxidation of metallic Eu in CH3CN.The interaction of the BF4- ions with the Eu(III) center was established by molecular weight, conductivity, and 11B and 19F NMR spectral measurements. 1 was found to exist as a dimer in CH3CN.In addition, it behaved as a 1:2 electrolyte, indicating the coordination of two of the BF4- ions per Eu(III) ion.However, the conductivity increased when chelating amines were added due to the partial displacement of the coordinated BF4- ions.The 11B and 19F NMR spectra of 1 in CH3CN indicated the presence of two different types of BF4- anions, one of which was isotropically shifted due to interaction with the paramagnetic Eu(III) center.The coordinated BF4- anions could be displaced quantitatively by the addition of 2 equiv of NO3- ions per Eu(III) ion.A degenerate metathesis of the fluorine between the BF3 and the coordinated BF4- ions was observed when BF3 was added to a CH3CN solution of 1. 1 formed a charge-transfer complex with tetra-p-anisylethylene in CH3NO2 but not in CH3CN.In addition, 1 initiated the oligomerization and the polymerization of styrene, α-methylstyrene, and 1,3-cyclohexadiene in CH3NO2.The molecular weights of the polymers obtained increased markedly on lowering the reaction temperature.At room temperature, indan derivatives were obtained from α-methyl- and α-phenylstyrene.The rate of polymerization of styrene was markedly attenuated when CH3CN was used instead of CH3NO2. 1 also initiated the isomerization of quadricyclane and the ring-opening polymerization of 2(10)-pinene and cyclopropylbenzene in CH3NO2.
Fourier transform near-infrared absorption spectroscopic study of catalytic isomerization of quadricyclane to norbornadiene by copper(II) and tin(II) salts
Chuang, Eric Chau-Chin,Lin, King-Chuen
, p. 132 - 136 (2002)
By using Fourier transform near-infrared (NIR) absorption spectroscopy, we have investigated the catalytic conversion of quadricyclane to norbornadiene. Either CuSO4 in chloroform or SnCl2 in benzene is used as catalyst. To avoid the effect of sample heterogeneity, the reaction mixture is kept still without stirring. The NIR light beam is guided to propagate through the solution right above the surface of metal salt. The NIR absorption spectra are acquired at 5-min intervals for a reaction period of 6 h. The related concentrations of quadricyclane and norbornadiene in the temporal evolution are determined with the method of partial least squares. A kinetic model for the pseudo-first-order reaction is derived considering the diffusion motion. Accordingly, the second-order rate constant for the isomerization catalyzed by CuSO4 and SnCl2, respectively, are determined to be (1.38 ?± 0.04) ?? 10-3 and (4.62 ?± 0.09) ?? 10-3 min-1 g-1. The norbornadiene is produced via a one-site coordination between the reactant and the catalyst. The product contribution from the intermediate of a two-site coordination is negligible in our system. The obtained result for CuSO4 is comparable with that detected by using Raman spectroscopy.
Valence Isomerization of Quadricyclene Mediated by Illuminated Semiconductor Powders
Ikezawa, Hideo,Kutal, Charles
, p. 3299 - 3303 (1987)
Quadricyclene undergoes valence isomerization to norbornadiene in the presence of photoexcited n-type semiconductor powders.For samples irradiated under comparable conditions of time and intensity, the yield of the diene product varies with (i) the semiconductor in the order CdS > TiO2 > ZnO and (ii) the solvent in the order dichloromethane > acetonitrile > tetrahydrofuran.The presence of oxygen in a sample diminishes the product yield, whereas both methylviologen dication and diphenylamine enhance the yield.The quantum efficiency of norbornadiene production appearsto be rather low (ca. 10-2 for CdS) in these heterogeneous systems.These observations are interpreted in terms of the redox chemistry that results upon interaction of the photogenerated electron-hole pairs in the semiconductor with the surrounding organic medium.
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Hogeveen,Nusse
, p. 3667,3668 (1973)
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Overtone Vibrational Photochemistry of Quadricyclane
Lishan, David G.,Reddy, K. V.,Hammond, George S.,Leonard, Jack E.
, p. 656 - 660 (1988)
The photochemistry of quadricyclane (Q) was explored by single-photon excitation to high vibrational levels.Spectra of the ν = 4-7 carbon-hydrogen overtones were recorded by using intracavity absorption and photoacoustic detection.These spectra were compared to the infrared fundamental spectrum and assigned.Excitation of the ν = 5 and ν = 6 bands of cyclopropanoid and methylenic hydrogens leads to reaction.At least one intermediate, probably a vibrationally excited form of norbornadiene (N), must be involved because partitioning among various reaction channels is pressure dependent.Apparent rate constants were measured and correlated with variations in pressure according to the Stern-Volmer relationship.Experimental values were compared with rate constants calculated by RRKM theory.Although there is a modest amount of "excess" reaction observed for the lowest excitation energies above threshold, overall evaluation provides no significant evidence for concentration of energy in localized modes for times that are long compared with reaction times.
Kinetics of the Isomerization of Quadricyclane to Norbornadiene Promoted by Tin(II) Chloride and Palladium(II) Chloride
Patrick, Timothy B.,Bechtold, Dana S.
, p. 1935 - 1937 (1984)
The conversion of quadricyclane to norbornadiene is promoted by both SnCl2 and PdCl2.The SnCl2 reaction occurs by a second-order process with activation parameters of ΔG(excit.), ΔH(excit.), and ΔS(excit.) of 22.5 kcal/mol, 13.9 kcal/mol, and -28.7 eu, respectively.The PdCl2-promoted reaction occurs by formation of an equilibrium species and follows Michaelis-Menton kinetics.A theoretical interpretation based on the Dewar-Duncanson model of bonding of metal ions with olefins is used to describe possible mechanistic differences in the reactions.
Triplex Promoted Intersystem Crossing of Ion-Radical pairs in the Photosensitized Valence Isomerization of Quadricyclane: Chemically Induced Dynamic Nuclear Polarization (CIDNP) Evidence
Yang, Li,Zhang, Mao-Xi,Liu, You-Cheng,Liu, Zhong-Li,Chow, Yuan L.
, p. 1055 - 1056 (1995)
Photosensitized valence isomerization of quadricyclane to norbornadiene by dibenzoylmethanatoboron difluoride in the presence of durene shows a CIDNP effect which is opposite in direction to that occurring in the absence of durene, demonstrating possible participation of triplexes in the durene co-sensitized reaction.
Reactions of Quadricyclane with Sulphur Dioxide: Formation of a Stable β-Sultine and Catalysed Isomerization to Norbornadiene
Lucchi, Ottorino De,Lucchini, Vittorio
, p. 464 - 465 (1982)
Sulphur dioxide, as solvent or in chloroform, catalyses the isomerization of quadricyclane (1) to norbornadiene and cycloadds to (1) to afford exo-3-oxa-4-thiatricyclo2,5>non-7-ene 4-oxide (3); in the presence of a deficiency of sulphur dioxide, (3) is remarkably stable in solution, but decomposes rapidly as pure product.
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Frey
, p. 365 (1964)
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Rhodium(I) complexes of the conformationally rigid IBioxMe4 ligand: Preparation of mono-, bis-, and tris-ligated NHC complexes
Chaplin, Adrian B.
, p. 3069 - 3077 (2014)
The preparation and characterization of a series of mono-, bis-, and tris-ligated rhodium(I) complexes of Glorius' conformationally rigid bioxazoline-derived N-heterocyclic carbene ligand IBioxMe4 are described. Through reaction of [Rh(COE)2Cl]2 (COE = cis-cyclooctene) with isolated IBioxMe4, [Rh(IBioxMe 4)(COE)Cl]2 (1), trans-[Rh(IBioxMe4) 2(COE)Cl] (2), and [Rh(IBioxMe4)3Cl] (3) were each isolated by careful choice of the reaction conditions. Further substitution and salt metathesis reactions of 1-3 were investigated, and derivatives containing CO, norbornadiene, and cyclopentadienyl ancillary ligands were readily isolated. Notably, halide abstraction from 2 and 3 using Na[BAr F4] (ArF = 3,5-C6H 3(CF3)2) resulted in the formation of low-coordinate T-shaped cis-[Rh(IBioxMe4)2(COE)][BAr F4] (9) and [Rh(IBioxMe4)3][BAr F4] (11). The solid-state structures of 2, 9, and 11 each feature IBioxMe4 ligands that bind unusually with tilted coordination geometries.
Alumina-Anchored Cobalt Porphine Catalysts for the Conversion of Quadricyclane to Norbornadiene
Miki, Sadao,Asako, Yoshinobu,Morimoto, Masayoshi,Ohno, Toshinobu,Yoshida, Zen-ichi,et al.
, p. 973 - 982 (1988)
Methods are described for the preparation of cobalt(II) deuteroporphyrin and cobalt(II) tetrakis(p-sulfonatophenyl)porphine anchored on alumina beads coated with polyaminesulfone-A.Wavelength dispersive X-ray microanalysis showed that the cobalt(II) porphine distributes within the catalyst outer surface layer of ca. 100 μm depth.The catalysts are highly active for the cycloreversion of quadricyclane to norbornadiene.A detailed kinetics of the isomerization using an isothermal recycle reactor gave a rate expression of Langmuir-Hinshelwood type.The catalysts gradually lose their activity, which can be regenerated completely by heating the catalysts at 200 deg C in vacuo.
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Walsh,Wells
, p. 149,150, 151 (1975)
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Herndon,Lowry
, p. 1922 (1964)
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Thermal Decomposition of a Series of 1,2-Diazetines
Breton, Gary W.,Shugart, John H.
, p. 8643 - 8649 (2003)
A homologous series of tricyclic diazetines (6a-c), differing by the number of methylene groups in the saturated bridges of the fused carbon bicycles, was synthesized. The ΔH? of decomposition for each of the diazetines to afford N2 and the corresponding alkene was determined experimentally: 6a, 31.7; 6b, 39.3; 6c, 38.8 kcal/mol. The ground-state strain energy of each diazetine was estimated utilizing computationally obtained ΔHf's for each of the experimentally investigated diazetines as well as several other diazetines whose ΔH?'s had been previously reported in the literature. The sum of the ground-state strain energies and ΔH?'s of decomposition for all of the diazetines was nearly constant, with an average value of 59 kcal/mol, suggesting that all of the diazetines decompose via the same mechanism. Generally, the higher the ground-state strain energy of the diazetine, the less the ΔH? for decomposition. The decomposition transition states for 6a-c and 7 were modeled computationally at the RB3LYP/6-311+G(3df,2p)//UB3LYP/6-31+G(d,p) level. The agreement of the experimentally determined ΔH? values with transition-state energies obtained computationally supports the reaction mechanism originally proposed by Yamabe that the elimination process occurs by an unsymmetrical, yet concerted, transition state with strong biradical character.
Cycloreversion of Quadricyclane to Norbornadiene Catalyzed by Tin (II) Complexes
Landis, M.E.,Gremaud, D.,Patrick, T.B.
, p. 375 - 378 (1982)
The conversion of quadricyclane (1) to norbornadiene (2) is catalyzed by stannous chloride and stannous chloride-phosphine complexes.A newly synthesized polymer-bound phosphine-stannous chloride complex also proved effective in the catalytic conversion 1 to 2.
Abel, E. W.,Bennet, M. A.,Wilkinson, G.
, (1959)
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Murov et al.
, p. 2957 (1968)
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PHOTOINDUCED ADDITION OF NUCLEOPHILES TO BICYCLOHEPTA-2,5-DIENE
Gassman, Paul G.,Olson, Kurt D.
, p. 19 - 22 (1983)
The 1-cyanonaphthalene photosensitized addition of water and methanol to the cation-radical of bicyclohepta-2,5-diene is described.
REDOX-AUXILIARY CATALYSIS
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Paragraph 0007; 0101, (2015/05/26)
Disclosed herein is a method of activating a compound for a chemical reaction comprising functionalizing a compound with a redox auxiliary group and oxidizing the redox auxiliary group that is bonded to the compound, thereby activating the compound, wherein the activated compound undergoes a chemical reaction to form a product and the oxidation of the redox auxiliary group is reversible. Methods of making and using these materials are also disclosed.