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Norbornadiene
About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.
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17 Jun 2022
TL;DR: In this article , a new family of bidentate dicationic phosphine ligands incorporating an additional electron donating group was designed and synthesized, and the obtained ligands were characterized using spectroscopical methods and single crystal diffraction.
Abstract: A new family of bidentate dicationic phosphine ligands incorporating an additional electron donating group was designed and synthesized. Obtained ligands were characterized using spectroscopical methods and single crystal diffraction. In comparison with previously established monodentate cationic phosphines, the new ligands allowed to coordinate not only electron rich transition metals such as Au(I) or Pt(II), but also Rh(I) and Ir(I). In order to evaluate the application of new phosphine ligands, the obtained complexes were tested in model reactions. A study of hydroarylation of 1,3 butadiene with electron rich aromatic nucleophiles was performed. Scope and limitation of this reaction was tested, in addition to mechanistic studies. Moreover, obtained Rh(I) complexes were proven to be active catalysts of 2+2+2 Homo Diels-Alder dimerization of norbornadiene derivatives. A family of new norbornadiene dimers was obtained using this methodology. Further mechanistic studies, isolation of reaction intermediates and post-synthetic functionalization were investigated.
TL;DR: By action of insoluble catalysts, cobalt tetraphenylporphyrin or cobalt phthalocyanine adsorbed on activated carbon, water-soluble quadricyclane derivative was isomerized to norbornadiene derivative under release of heat in an alkaline solution as mentioned in this paper.
Abstract: By action of insoluble catalysts, cobalt tetraphenylporphyrin or cobalt phthalocyanine adsorbed on activated carbon, water-soluble quadricyclane derivative was isomerized to norbornadiene derivative under release of heat in an alkaline solution. The activities of these insoluble catalysts were as high as those of water-soluble catalysts.
TL;DR: In this paper, a cyclohexane-annelated cyclopentadiene was shown to have an exceptionally large radiative rate constant of 13 × 108 s−1, with a red-shifted unstructured additional emission band with a dipole moment of 32 D.
Abstract: When heated in pyridine at 80 °C, pentacarbonyl[(2E)-3-cyclohexenyl-3-(dimethylamino)-1-ethoxy-2-propen-1-ylidene]chromium (1-Cr) and -tungsten (1-W) complexes undergo 6π-electrocyclization and subsequent reductive elimination to yield the cyclohexane-annelated cyclopentadiene 6, which equilibrates by 1,5-hydrogen shift with its more reactive isomer 7. The latter molecule is efficiently trapped in Diels−Alder reactions with various alkynes 2 and styrenes 8 to give the cyclohexane-annelated norbornadiene 3 and norbornene derivatives respectively, with high regio- and diastereoselectivity in 15−91% yields. The enol ether moiety in compound 3 is particularly easily hydrolyzed, probably due to the through-space interaction between the two double bond moieties, so that the norbornenone derivatives 4 are isolated in all but one case after chromatographic purification. In this reaction, the tungsten complex 1-W consistently gave lower yields than 1-Cr. Arylalkynes with strongly electron-withdrawing groups and minimal steric congestion are particularly suitable reaction partners for 7. The formation of bis-cycloadducts 10 from suitable diynes largely depends upon the steric and electronic properties of the corresponding alkynyl-substituted mono-cycloaddition products of type 4 or 11. With the fluorenyl-substituted tricycle 4w in acetonitrile at 25 °C, but not with 4y, dual fluorescence is observed, with a red-shifted unstructured additional emission band with a dipole moment of 32 D, originating from intramolecular charge transfer. The molecule 2y has an exceptionally large radiative rate constant of 13 × 108 s−1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
TL;DR: In this paper, the reactions of diene complexes with the nucleophiles OPri-, NH2Ph, SPh-and SCN-nucleophiles were investigated and the dicyclopentadiene complex undergoes attack at the diene in each case.
Abstract: The reactions of the complexes [Pt(diene)Cl2](diene = norbornadiene or dicyclopentadiene) with the nucleophiles OPri–, NH2Ph, SPh–, and SCN– have been investigated. The dicyclopentadiene complex undergoes attack at the diene in each case and the S-nucleophiles also give substitution at platinum. Onlythelatterreactionoccurswith the norbornadiene complexes and S-nucleophiles, but attack on the organic ligand is found with OPri– and NH2Ph, The reactions of these products with neutral uni- and bi-dentate ligands usually leads to bridge-splitting reactions, but in some cases the norbornenyl derivatives undergo rearrangement to nortricyclene systems. The reaction of the alkenyl complexes with a further nucleophile (OMe– or NHPh–) to give doubly σ-bonded alkyleneplatinum complexes is described.
TL;DR: In this article, the reactions of norbornadiene in amine by the use of nickel, palladium and rhodium complexes have been studied in the presence of protic acid.
Abstract: The reactions of norbornadiene in amine by the use of nickel, palladium and rhodium complexes have been studied in the presence of protic acid. A catalytic system of Ni(COD)2 (1)-n-Bu3P gives a mixture of 5-exo-(o-tolyl)-2-norbornene (3) and 5-exo-(N-amino)-2-norbornene (4). Bis(triphenylphosphine)(maleic anhydride)palladium (5) gives 3-(N-amino)nortricyclene (6). Dichlorotetrakis(cyclooctene)dirhodium (10) gives a [2+4] cycloaddition product (11). All these reactions mechanisms are discussed from the point of view of an acid-promoted reaction on low-valent transition metal complexes.