Showing papers on "Norbornadiene published in 2017"
TL;DR: A novel palladium-catalyzed three-component reaction of phenol-derived biaryls with N-benzoyloxyamines and norbornadiene (NBD) has been developed for the assembly of highly functionalized spiroindenes, highlighting the potential synthetic utility of this methodology.
Abstract: A novel palladium-catalyzed three-component reaction of phenol-derived biaryls with N-benzoyloxyamines and norbornadiene (NBD) has been developed for the assembly of highly functionalized spiroindenes. This domino process was realized through NBD-assisted C-H amination and phenol dearomatization by forming one C-N bond and two C-C bonds in a single step. Preliminary studies indicated that asymmetric control of this transformation was feasible with chiral ligands. Moreover, the potential synthetic utility of this methodology was highlighted by a series of further transformations.
97 citations
TL;DR: A versatile π-extension reaction was developed based on the three-component cross-coupling of aryl halides, 2-haloarylcarboxylic acids, and norbornadiene, which serves as an ortho-C-H activator and ethylene synthon via a retro-Diels-Alder reaction.
Abstract: A versatile π-extension reaction was developed based on the three-component cross-coupling of aryl halides, 2-haloarylcarboxylic acids, and norbornadiene. The transformation is driven by the direction and subsequent decarboxylation of the carboxyl group, while norbornadiene serves as an ortho-C-H activator and ethylene synthon via a retro-Diels-Alder reaction. Comprehensive DFT calculations were performed to account for the catalytic intermediates.
88 citations
TL;DR: The heptanuclear cluster Ba7 H7 [N(SiMe3 )2 ]7 is a very strong reducing agent that already at room temperature reacts with Me3 SiCH=CH2, norbornadiene, and ethylene and slowly decomposes to undefined barium hydride species.
Abstract: Reaction of Ba[N(SiMe3)2]2 with PhSiH3 in toluene gave simple access to the unique Ba hydride cluster Ba7H7[N(SiMe3)2]7 that can be described as a square pyramide spanned by five Ba2+ ions with two flanking BaH[N(SiMe3)2] units. This heptanuclear cluster is well soluble in aromatic solvents and the hydride 1H NMR signals and coupling pattern suggests that the structure is stable in solution. At 95 °C, no coalescence of hydride signals is observed but the cluster slowly decomposes to undefined Ba hydride species. Complex Ba7H7[N(SiMe3)2]7 is a very strong reducing agent that already at room temperature reacts with Me3SiCH=CH2, norbornadiene and ethylene. The highly reactive alkylbarium intermediates cannot be observed and deprotonate the (Me3Si)2Nˉ ion, as confirmed by the crystal structure of Ba14H12[N(SiMe3)2]12[(Me3Si)(Me2SiCH2)N]4.
54 citations
TL;DR: A new photoelectrochemical infrared reflection absorption spectroscopy (PEC-IRRAS) experiment is presented, which allows monitoring of the complete energy storage and release cycle by in situ vibrationalSpectroscopy.
Abstract: The two valence isomers norbornadiene (NBD) and quadricyclane (QC) enable solar energy storage in a single molecule system We present a new photoelectrochemical infrared reflection absorption spectroscopy (PEC-IRRAS) experiment, which allows monitoring of the complete energy storage and release cycle by in situ vibrational spectroscopy Both processes were investigated, the photochemical conversion from NBD to QC using the photosensitizer 4,4′-bis(dimethylamino)benzophenone (Michler’s ketone, MK) and the electrochemically triggered cycloreversion from QC to NBD Photochemical conversion was obtained with characteristic conversion times on the order of 500 ms All experiments were performed under full potential control in a thin-layer configuration with a Pt(111) working electrode The vibrational spectra of NBD, QC, and MK were analyzed in the fingerprint region, permitting quantitative analysis of the spectroscopic data We determined selectivities for both the photochemical conversion and the electroch
49 citations
TL;DR: A recent review of the progress in organo- f-element chemistry can be found in this article, where a number of interesting contributions have been made in the field of organolanthanide catalysis, with an emphasis on Ln-catalyzed olefin and diene polymerization.
42 citations
TL;DR: In this paper, a chiral neutral CpxRu(II)Cl complex was designed based on an atropchiral cyclopentadienyl (Cpx) ligand which is accessed in a streamlined C-H functionalisation approach.
Abstract: Cyclopentadienyl ruthenium(II) complexes with a large number of available coordination sites are frequently used catalysts for a broad range of transformations. To be able to render these transformations enantioselective, we have designed a chiral neutral CpxRu(II)Cl complex basing on an atropchiral cyclopentadienyl (Cpx) ligand which is accessed in a streamlined C–H functionalisation approach. The catalyst displays excellent levels of reactivity and enantioselectivity for enantioselective [2+2]-cycloadditions leading to strained chiral cyclobutenes, allowing for catalyst loadings as low as 1 mol%. A very strong counterion effect of a bound chloride anion transforms the corresponding unselective cationic complex into a highly enantioselective neutral version. Moreover, by adding norbornadiene at the end of the reaction the catalyst can be recovered and subsequently reused.
41 citations
TL;DR: The synthesis and conductance properties of a new type of robust molecular photothermal switch based on the norbornadiene–quadricyclane system are presented and the prevailing assumption that current will simply flow through the shortest through-bond path in a molecule is challenged.
Abstract: Integrating functional molecules into single-molecule devices is a key step toward the realization of future computing machines based on the smallest possible components. In this context, photoswitching molecules that can make a transition between high and low conductivity in response to light are attractive candidates. Here we present the synthesis and conductance properties of a new type of robust molecular photothermal switch based on the norbornadiene (NB)-quadricyclane (QC) system. The transport through the molecule in the ON state is dominated by a pathway through the π-conjugated system, which is no longer available when the system is switched to the OFF state. Interestingly, in the OFF state we find that the same pathway contributes only 12% to the transport properties. We attribute this observation to the strained tetrahedral geometry of the QC. These results challenge the prevailing assumption that current will simply flow through the shortest through-bond path in a molecule.
36 citations
TL;DR: A strain-induced C-C oxidative addition of norbornadiene is described, mediated by a dinuclear Ni complex, which also serves as a catalyst for the carbonylative rearrangement of nor Bornadiene to form a bicyclo[3.3.0] product.
Abstract: Single bonds between carbon atoms are inherently challenging to activate using transition metals; however, ring-strain release can provide the necessary thermodynamic driving force to make such processes favorable. In this report, we describe a strain-induced C–C oxidative addition of norbornadiene. The reaction is mediated by a dinuclear Ni complex, which also serves as a catalyst for the carbonylative rearrangement of norbornadiene to form a bicyclo[3.3.0] product.
33 citations
TL;DR: Investigation of the surface chemistry of the polycyclic valence-isomer pair norbornadiene (NBD) and quadricyclane (QC) on Pt(111) shows a norbornadienyl intermediate species that is stable up to approximately 380 K, which implies that the energy-loaded QC molecule is stable in this state.
Abstract: We have investigated the surface chemistry of the polycyclic valence isomer pair norbornadiene (NBD) and quadricyclane (QC) on Pt(111). NBD/QC is considered a prototype system for energy storage in strained organic compounds. With our multimethod approach, including UV photoelectron spectroscopy, high resolution X-ray photoelectron spectroscopy, infrared reflec¬tion absorption spectroscopy and density functional theory calculations, we can unambiguously identify and differentiate between the two molecules in the multilayer phase which implies that the energy-loaded QC is stable in this state. Upon adsorption in the (sub)monolayer regime, the different spectroscopies yield identical spectra for NBD and QC at 125 K and also at 160 K, when multilayer desorption takes place. This behavior is explained by a rapid cycloreversion of QC to NBD upon contact with the Pt surface. The NBD adsorbs in a η2:η1 geometry with an agostic Pt-H interaction of the bridgehead CH2 subunit and the surface. Between 190 and 220 K, strong spectral changes are observed, because the hydrogen atom forming the agostic bond is broken. This reaction yields a norbornadienyl intermediate species which is stable up to ~ 380 K. At higher temperatures, the molecule dehydrogenates and decomposes into smaller carbonaceous fragments.
26 citations
TL;DR: 1H NMR studies of the reactions of 4a or 4b with tert-butylethylene indicated the existence of an apparently unique reversible β-hydride elimination from the bicyclic substituted aryl/alkyl stannylenes 2a or 2b and 3a or 3b.
Abstract: Reactions of the Sn(II) hydrides [ArSn(μ-H)]2 (1) (Ar = AriPr4 (1a), AriPr6 (1b); AriP4 = C6H3-2,6-(C6H3-2,6-iPr2)2, AriPr6 = C6H3-2,6-(C6H2-2,4,6-iPr3)2) with norbornene (NB) or norbornadiene (NBD) readily generate the bicyclic alkyl-/alkenyl-substituted stannylenes, ArSn(norbornyl) (2a or 2b) and ArSn(norbornenyl) (3a or 3b), respectively. Heating a toluene solution of 3a or 3b at reflux afforded the rearranged species ArSn(3-tricyclo[2.2.1.02,6]heptane) (4a or 4b), in which the norbornenyl ligand is transformed into a nortricyclyl group. 1H NMR studies of the reactions of 4a or 4b with tert-butylethylene indicated the existence of an apparently unique reversible β-hydride elimination from the bicyclic substituted aryl/alkyl stannylenes 2a or 2b and 3a or 3b. Mechanistic studies indicated that the transformation of 3a or 3b into 4a or 4b occurs via a β-hydride elimination of 1a or 1b to regenerate NBD. Kinetic studies showed that the conversion of 3a or 3b to 4a or 4b is first order. The rate constant k...
23 citations
TL;DR: In this article, the authors have shown that polyacetylenes (SPA) can be prepared using a [Rh(norbornadiene)Cl]2-amine or alcohol catalyst along with the reason for why the Rh catalytic system was used.
Abstract: Interconvertible stretched and contracted helices of mono-substituted polyacetylenes (SPA)s prepared using a [Rh(norbornadiene)Cl]2-amine or alcohol catalyst are demonstrated along with the reason for why the Rh catalytic system was used. The interconversions between their helices with color changes in the solid state were controlled by choosing the polymerization solvents, substituents, and/or external stimuli. The accordion-like helix oscillation, HELIOS, of the aliphatic polyacetylene ester main chain was found in a solution where restricted rotations around the O‒C bond in the ester side-chain are dynamically synchronized. The magnetic behavior of the cis and trans radicals of SPAs produced through the rotational scission of the cis C=C bonds is also reported.
TL;DR: The norbornadiene-like bimetallic dimer was prepared by direct extraction from a ternary alloy with nominal composition "K6ZnSb5" in ethylenediamine/toluene/2, 2,2,2-crypt solutions and shows covalent bonding between the Zn and Sb atoms.
TL;DR: Novel bridged bicyclic ring systems are accessible from the diol, α-ketol or 1,2-dione oxidation levels with complete control of diastereoselectivity.
Abstract: Highly exo-selective ruthenium(0) catalyzed transfer hydrogenative cycloadditions of 1,2-diols with cyclohexadiene or norbornadiene are described. Novel bridged bicyclic ring systems are accessible from the diol, α-ketol or 1,2-dione oxidation levels with complete control of diastereoselectivity.
TL;DR: In this paper, the effect of the incorporation of aluminum on the catalytic performance of KIT-6 in the norbornadiene cyclodimerization reaction was investigated, and it was shown that the performance of the Al-Kit-6 catalyst was higher than that of the MCM-41 catalyst.
TL;DR: The bimetallic cluster {W2} is not only a cost-efficient, practical, highly active, and cis-stereoselective ROMP-initiator, but it can also be used for the synthesis of more complex macromolecular structures.
Abstract: The bimetallic cluster Na[W2(μ-Cl)3Cl4(THF)2]·(THF)3 ({W2}, {W 3 W}6+, a′2e′4), which features a triple metal-metal bond, is a highly efficient room-temperature initiator for ring opening metathesis polymerization (ROMP) of norbornene (NBE) and norbornadiene (NBD), providing high-cis polymers. In this work, {W2} was used for the copolymerization of the aforementioned monomers, yielding statistical poly(norbornene)/poly(norbornadiene) PNBE/PNBD copolymers of high molecular weight and high-cis content. The composition of the polymer chain was estimated by 13C CPMAS NMR data and it was found that the ratio of PNBE/PNBD segments in the polymer chain was relative to the monomer molar ratio in the reaction mixture. The thermal properties of all copolymers were similar, resembled the properties of PNBD homopolymer and indicated a high degree of cross-linking. The morphology of all materials in this study was smooth and non-porous; copolymers with higher PNBE content featured a corrugated morphology. Glass transition temperatures were lower for the copolymers than for the homopolymers, providing a strong indication that those materials featured a branched-shaped structure. This conclusion was further supported by viscosity measurements of copolymers solutions in THF. The molecular structure of those materials can be controlled, potentially leading to well-defined star polymers via the “core-first” synthesis method. Therefore, {W2} is not only a cost-efficient, practical, highly active, and cis-stereoselective ROMP-initiator, but it can also be used for the synthesis of more complex macromolecular structures.
TL;DR: In this article, the bromination reaction of p-benzoquinone-fused norbornadiene was studied at various temperatures (−78,−−50, 0, 25, and 77,°C).
TL;DR: In this paper, the anchoring of the molecular energy carrier norbornadiene (NBD) to an atomically defined oxide surface was investigated by synthesizing a carboxyl-functionalized NBD derivative, namely 1-(2′-norbornadienyl)pentanoic acid (NBDA), and deposited it by physical vapor deposition (PVD) under ultrahigh vacuum (UHV) conditions onto a well-ordered Co3O4(111) film grown on Ir(100).
Abstract: We have investigated the anchoring of the molecular energy carrier norbornadiene (NBD) to an atomically defined oxide surface. To this end, we synthesized a carboxyl-functionalized NBD derivative, namely 1-(2′-norbornadienyl)pentanoic acid (NBDA), and deposited it by physical vapor deposition (PVD) under ultrahigh vacuum (UHV) conditions onto a well-ordered Co3O4(111) film grown on Ir(100). In addition, we performed a comparative growth study with benzoic acid (BA) under identical conditions which was used as a reference. The interaction and orientation of NBDA and BA with the oxide surface were monitored in situ during film growth by isothermal time-resolved infrared reflection–absorption spectroscopy (TR-IRAS), both below and above the multilayer desorption temperature. The thermal behavior and stability of the films were investigated by temperature-programmed IRAS (TP-IRAS), with help of density functional (DF) calculations. BA binds to Co3O4(111) under formation of a symmetric chelating carboxylate wi...
TL;DR: It is determined that the reversion of the quadricyclanes occurs via a free radical mechanism with very little contribution from polar effects, and speculation is speculated as to whether this data may form the basis for a freeradical substituent constant, σQ•, analogous to the traditional Hammett σ parameter.
Abstract: In this Article, we present a new method for the synthesis of diarylnorbornadiene derivatives. Through the use of a two-step procedure consisting of a tandem alkene insertion-Suzuki coupling reaction followed by a DDQ dehydrogenation, we have been able to synthesize derivatives with a wide variety of substituents. We also present the results of UV–visible spectroscopy studies and kinetics experiments that show the effect of substituent on light absorption properties of the norbornadienes as well as the kinetic stability of the quadricyclanes that result from their photochemical conversion. While substitution on the aromatic rings had comparatively little effect on quadricyclane lability, substitution at a bridgehead position with a methyl group produced a quadricyclane that thermally reverted to the norbornadiene at a rate that was significantly slower than that for the quadricyclane without the methyl substituent. From the results of the kinetics experiments, we determined that the reversion of the quadr...
TL;DR: In this paper, the effects of the pore structure and acidity of the catalysts on the NBD dimerization reaction were evaluated using HY, Hbeta, HZSM-5 and Al-MCM-41 catalysts.
Abstract: The activities of HY, Hbeta, HZSM-5 and mesoporous Al-MCM-41 catalysts were evaluated during the dimerization of bicyclo[2.2.1]hepta-2,5-diene (norbornadiene, NBD). This study focuses on the effects of the pore structure and acidity of the catalysts on the NBD dimerization reaction. When conducting the NBD dimerization reaction over the HY, Hbeta, HZSM-5 and Al-MCM-41 catalysts, it was confirmed that NBD dimer (NBDD) synthesis could be facilitated at a temperature of 250 °C, whereas NBD scarcely reacts through a thermal reaction without a catalyst. Although the NBD conversion rates of the four catalysts are nearly identical after a 12-h reaction, the HY zeolites showed much higher selectivity to NBDD than those with the Hbeta, HZSM-5 and Al-MCM-41 catalysts. The HY catalyst showed the highest yield, reaching 41.5 wt% after a 12-h reaction. The higher selectivity of the HY catalyst during the dimerization of NBD could be explained in terms of its appropriate pore structure and by the higher concentration of Bronsted acid sites. The present study reveals that the HY zeolite is a potential heterogeneous catalyst for NBDD synthesis through the dimerization of NBD at a high yield.
TL;DR: In this paper, a metathesis mechanism was proposed to explain the steric repulsion between the pendant group of a polyphenylacetylene and the propagation chain.
TL;DR: In this paper, the feasibility of controlling selectivity and reaction rate has been shown for cyclic dimerization, co-dimerization, isomerization and allylation of NBD.
Abstract: A wide range of rare polycyclic hydrocarbons can be obtained through catalytic processes involving norbornadiene (NBD). The problem of selectivity is crucial for such reactions. The feasibility of controlling selectivity and reaction rate has been shown for cyclic dimerization, co-dimerization, isomerization and allylation of NBD. Kinetic rules have been scrutinized. Consistent mechanisms have been proposed. Factors affecting directions of the reactions and allowing us to obtain individual stereoisomers quantitatively, have been established. A series of novel unsaturated compounds has been synthesized; they incorporate a set of double bonds with different reactivity and can find an extremely wide range of applications. Eurasian ChemTech Journal 3 (2001) 73-90 2001 al-Farabi Kazakh St.Nat. University Introduction The importance of NBD and its derivatives in various fields of human activity is growing. More and more new applications are being discovered for these compounds. Since they were first obtained less than 50 years ago, these substances have been successfully utilized in medicine, agriculture, rocketry, syntheses of polymers with unique properties, microelectronics, and as solar energy converters. The number of patents concerned with synthesis and application of NBD derivatives and norbornene-2 (NBN) had exceeded 100 hundreds by the year 2000. Due to their unique structure, compounds with NBD and NBNmoieties are achieving the leading positions in contemporary chemistry and chemical technology [1-3]. It should be strongly emphasized that NBD itself and some of its simplest derivatives are obtained from chemicals, produced on a large scale during oil processing [4]. They are cyclopenta-1,3-diene (CPD), acetylene, alkenes, and alkadienes with various structures. Production of CPD can easily be combined with synthesis of other petrochemical products, for example ethylene. Today, a large proportion of CPD cannot be duly utilized, so it is very important to search for new ways of its utilization. Even though NBD has extremely rich synthetic possibilities, its utilization as a universal substrate is rather limited, since NBD-derivatives can form all kinds of isomers: skeleton, regio, stereo, enantio ones. A resultant mixture of isomeric products is often difficult to separate and analyze, and the consumption of reagents may become excessive. All this restricts widespread use of NBD. Metal-complex catalysis is very interesting and attractive for solving various problems connected with selectivity [5]. By applying its tenets and methods to reactions involving NBD and its derivatives, by scrutinizing mechanisms of reactions, we can control structure and range of regioand stereo isomers, synthesize new compounds of this type, and can make their production sensible from technological and economical points of view. The present article bases on several research directions concerned with application of the above-mentioned methods in some of the most promising processes involving NBD.
TL;DR: The tetranuclear complex has been characterized by X-ray diffraction studies and exhibits a very unusual cisoid geometry in both the disposition of the C,N-chelate ligands and the position of the palladium centers as mentioned in this paper.
TL;DR: In this article, both cis-and trans-rich poly[p-(trimethylsilyl)phenylacetylene]s (PTM-SPAs) were synthesized using [Rh(norbornadiene)Cl]2-TEA (TEA: triethylamine) and WCl6-Ph4Sn as catalysts, respectively.
Abstract: Both cis- and trans-rich poly[p-(trimethylsilyl)phenylacetylene]s (PTM-SPAs) were synthesized using [Rh(norbornadiene)Cl]2-TEA (TEA: triethylamine) and WCl6-Ph4Sn as catalysts, respectively. The Rh-based cis-rich polymer exhibited a remarkable fluorescence (FL) emission enhancement after thermal annealing (heating at 200°C in N2 atmosphere for 1 min), while the pristine polymer was almost entirely non-emissive. NMR and Raman spectroscopic studies clarified the occurrence of irreversible cis-trans isomerization under thermal annealing and suggested that the FL emission increased with an increase in the trans content of PTMSPA. Computer simulations of 12-mer model compounds clarified that the FL emission is a result of intramolecular excimers formed from side-on π-stacking of phenyl groups, which is possible only along the backbone of the trans-based polymer.
TL;DR: In this article, the absolute configuration of two αvβ6 integrin inhibitors was established via degradation to the corresponding C3-aryl substituted butyrolactone via asymmetric synthesis using 1,4-addition of arylboronic acids to butenolide, catalysed by bis(norbornadiene)rhodium (I) tetrafluoroborate in the presence of (R)-BINAP, and confirmed by X-ray crystallography.
Abstract: The absolute configuration of two novel αvβ6 integrin inhibitors was established via degradation to the corresponding C3-aryl substituted butyrolactone. The configuration of the resulting lactones was established by asymmetric synthesis using 1,4-addition of arylboronic acids to butenolide, catalysed by bis(norbornadiene)rhodium (I) tetrafluoroborate in the presence of (R)-BINAP, and confirmed by X-ray crystallography. Studies on arylboronic acid conjugate additions to acyclic crotonate esters bearing a γ-oxygen substituent are also reported. Three Rh catalysts were investigated and the one giving the highest enantioselectivity was bis(norbornadiene)rhodium (I) tetrafluoroborate.
TL;DR: In this article, trispyrazolyl borate (Tp) ligands are highly modifiable to vary their steric and electronic properties, and the ability to selectively modify them after metal complexation would allow for rapid catalyst diversification.
TL;DR: In this paper, a racemic mixture and two chiral monomers of 2-methyl-1-butyl propiolate, i.e., rac1, R1, and S1, were stereoregularly polymerized with a catalyst, [Rh(norbornadiene)Cl]2, in methanol at 40 °C.
Abstract: A racemic mixture and two chiral monomers of 2-methyl-1-butyl propiolate, i.e., rac1, R1, and S1, were stereoregularly polymerized with a catalyst, [Rh(norbornadiene)Cl]2, in methanol at 40 °C to obtain the corresponding helical racemic and two chiral polymers, Prac1, PR1, and PS1, and a copolymer, Pco. The 1H and 13C NMR spectra of the racemic and chiral polymers differed, although the NMR spectra of their monomers were the same. The structures of the Pco copolymers with different chiral monomer ratios were analyzed using 1D and 2D NMR, optical rotation, circular dichroism (CD), UV–vis, and computational methods to elucidate the stereochemical effect of the chiral monomers together with the polymerization mechanism. The temperature dependence of 1H and 13C NMR spectra in line shape and intensity indicated that the helical main chain undergoes restricted rotation around the ester methylene bonds −O–CH2– through a three-site jump exchange called an accordion-like helix oscillation (HELIOS). The energetical...
Patent•
04 May 2017
TL;DR: In this article, a continuous distillation column has been installed to organize the continuous flow of the process and ensure the material and heat balance of the flows between the photochemical and catalytic modules allowing efficient separation of components such as norbornadiene and quadricyclan and directing them to the appropriate modules, regulating the cyclicity of the transformations.
Abstract: FIELD: chemistry.SUBSTANCE: continuous distillation column has been installed to organize the continuous flow of the process and ensure the material and heat balance of the flows between the photochemical and catalytic modules allowing efficient separation of components such as norbornadiene and quadricyclan and directing them to the appropriate modules, regulating the cyclicity of the transformations.EFFECT: increase in quantitative yield quadricyclane, requiring no further purification from the impurities, and the number of cycles to ensure continuity of the process.3 cl, 2 ex, 2 tbl, 1 dwg
Patent•
27 Dec 2017
TL;DR: In this paper, a method for producing dimers of norbornadiene-endo-end-hexacyclo[9.2.0.1.0]tetradecene-12 by dimerization under the action of the catalytic system Fe (acac)-AlEt-CH(CN) at the molar ratio of catalyst and reagent was presented.
Abstract: FIELD: chemistry.SUBSTANCE: invention relates to the method for producing dimer of norbornadiene-endo-endo-hexacyclo[9.2.1.0.0.0.0]tetradecene-12 by dimerization of norbornadiene under the action of the catalytic system Fe (acac)-AlEt-CH(CN)at the molar ratio of catalyst and reagent [Fe(acac)]:[CH(CN)]:[AlEt]:[norbornadiene]=1:1÷6:6÷10:100÷200 in toluene, at 110°C for 0.2 h. With complete conversion of norbornadiene, the yield of endo-endo-hexacyclo[9.2.1.0.0.0.0]tetradecene-12 reaches 93%.EFFECT: increasing the yield.1 tbl, 12 ex