Norbornadiene

About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.

Development of iron catalysts for hydrogenation and polymerization

Abstract: In the scope of this work, a series of new, easy to prepare iron hydrogenation catalysts have been introduced. Different aspects of this new hydrogenation catalysts such as iron source, activation reagent, substrates and efficiency were investigated. A ligand-free catalyst, prepared from an iron(II) chloride suspension activated with diisobutylaluminiumhydride (DIBAH), showed the highest activity. With this catalyst all kind of C-C double bonds like mono-, dior trisubstituted, acyclic or cyclic, isolated or conjugated double bonds as well as alkynes were hydrogenated quantitatively under mild conditions (3 bar hydrogen pressure, room temperature) within short time. Both TON and TOF scale with the added amount of activation reagent up to a 1:8 FeCl2/DIBAH ratio furnishing the most active catalyst with TON = 1900 and TOF = 125 in this case. With the exception of ethers and amines, the use of strong reducing agents as activators prevents the hydrogenation of functionalized olefins. In absence of hydrogen H2, catalytic activity for alkyne polymerization and cyclotrimerization was observed. Furthermore, this catalyst is able to promote the polymerization of acetylene. Attempts to identify the catalytic active species led to the development of a homogeneous precatalyst showing an amazing efficiency (TOF > 340 h-1). Derived from the assumed structure of this precatalyst, a series of allylbenzylethers were synthesized and tested as ligands. The corresponding catalysts, obtained by activation with alkyllithium reagents, display alkene hydrogenation and ethylene oligomerization activity. Abbreviations Ac Acetyl Bn Benzyl bpy 2,2’-Bipyridine Bz Benzoyl CHT Cycloheptatriene COD 1,5-Cyclooctadiene COE Cyclooctene COSY Correlated spectroscopy DAD 1,4-Diazadiene DAT 2,5-Diazatriene de Diastereomeric excess DFT Density functional theory DIBAH Diisobutylaluminiumhydride ee Enantiomeric excess EI Electron impact ENB 5-Ethylidene-2-norbornene ESI Electrospray ionisation Et Ethyl FAB Fast atom bombardement GC Gas chromatography HETCOR Heteronuclear correlation HMB Hexamethylbenzene HPB Hexaphenylbenzene iPr Isopropyl LAH Lithiumaluminiumhydride M Molar Me Methyl MMAO Modified methylaluminoxan MS Mass spectroscopy NBD Norbornadiene NMR Nuclear magnetic resonance PES Potential energy surface Ph Phenyl SEM Scanning electron microscope THF Tetrahydrofuran TOF Turn-over frequency TON Turn-over number UV-Vis Ultraviolet-visible VCH 4-Vinylcyclohexene

Catalyst for isomerization reaction

Abstract: PURPOSE:To obtain a catalyst for isomerization reaction through the use of inexpensive general-purpose resin, by bonding a metal complex of a porphine compound to porous polyolefin CONSTITUTION:A metal complex of a porphine compound (eg, cobalt complex of protoporphyrin) is bonded to polyolefin such as polyethylene made porous by solvent treatment As one available method of this bonding method, there exists one wherein activation ray such as gamma-ray is irradiated to porous polyolefin in contact relation to chloromethyl styrene under vacuum to carry out graft polymerization and the metal complex of the porphine compound is bonded to the resulting treated polyolefin For example, when thus obtained catalyst is introduced into an ether solution of quadricyclene to carry out reaction at a room temp for ten several hr, valency isomerization reaction is generated and quadricyclene is converted to norbornadiene at an almost 100% conversion ratio Because heat is generated during this reaction, this reaction can be utilized as a chemical heat accumulating material

Searches for bridged bicyclic molecules in space-norbornadiene and its cyano derivatives.

Abstract: The norbornadiene (NBD) molecule, C7H8, owes its fame to its remarkable photoswitching properties that are promising for molecular solar-thermal energy storage systems. Besides this photochemical interest, NBD is a rather unreactive species within astrophysical conditions and it should exhibit high photostability, properties that might also position this molecule as an important constituent of the interstellar medium (ISM)-especially in environments that are well shielded from short-wavelength radiation, such as dense molecular clouds. It is thus conceivable that, once formed, NBD can survive in dense molecular clouds and act as a carbon sink. Following the recent interstellar detections of large hydrocarbons, including several cyano-containing ones, in the dense molecular cloud TMC-1, it is thus logical to consider searching for NBD-which presents a shallow but non-zero permanent electric dipole moment (0.06 D)-as well as for its mono- and dicyano-substituted compounds, referred to as CN-NBD and DCN-NBD, respectively. The pure rotational spectra of NBD, CN-NBD, and DCN-NBD have been measured at 300 K in the 75-110 GHz range using a chirped-pulse Fourier-transform millimetre-wave spectrometer. Of the three species, only NBD was previously studied at high resolution in the microwave domain. From the present measurements, the derived spectroscopic constants enable prediction of the spectra of all three species at various rotational temperatures (up to 300 K) in the spectral range mapped at high resolution by current radio observatories. Unsuccessful searches for these molecules were conducted toward TMC-1 using the QUIJOTE survey, carried out at the Yebes telescope, allowing derivation of the upper limits to the column densities of 1.6 × 1014 cm-2, 4.9 × 1010 cm-2, and 2.9 × 1010 cm-2 for NBD, CN-NBD, and DCN-NBD, respectively. Using CN-NBD and cyano-indene as proxies for the corresponding bare hydrocarbons, this indicates that-if present in TMC-1-NBD would be at least four times less abundant than indene.

Method for producing ester compound and palladium catalyst used in method for producing ester compound

Abstract: A method for producing an ester compound, wherein an ester compound is obtained by reacting a compound having at least one cyclic structure, namely a norbornene ring and/or a norbornadiene ring, with an alcohol and carbon monoxide with use of a palladium catalyst and an oxidant so as to introduce an ester group to a carbon atom that constitutes a double bond in the cyclic structure. This method for producing an ester compound is characterized in that the palladium catalyst contains palladium acetate having a nitrite ligand represented by general formula (1) in an amount of 10% by mole or more in terms of metal. Pd3(CH3COO)5(NO2) (1).

Bis(bicyclo[2.2.1]hepta‐2,5‐diene)‐dichlorodirhodium

Abstract: [12257-42-0] C14H16Cl2Rh2 (MW 461.00) InChI = 1S/2C7H8.2ClH.2Rh/c2*1-2-7-4-3-6(1)5-7;;;;/h2*1-4,6-7H,5H2;2*1H;;/q;;;;2*+1/p-2 InChIKey = RXDWVIOULPVOEO-UHFFFAOYSA-L (catalyst for valence isomerization2 and N-heterocyclization;3 in combination with phosphorus ligands are catalysts for hydrogenation of many functional groups5, 6 and hydroformylation; with chiral ligands are catalysts for asymmetric hydrogenation7-11) Alternate Name: dichlorobis(norbornadiene)dirhodium. Physical Data: mp 240 °C dec. Solubility: sol chloroform and benzene; insol ether and light petroleum. Form Supplied in: yellow crystals. Preparative Methods: Rhodium(III) Chloride and bicyclo[2.2.1]hepta-2,5-diene in aq ethanol, when shaken for 2 days, give a yellow deposit. Purification: recrystallized from chloroform and light petroleum. Handling, Storage, and Precautions: air stable up to 240 °C.