4982-34-7Relevant academic research and scientific papers
Scandium complexes with the tetraphenylethylene and anthracene dianions
Ellis, John E.,Minyaev, Mikhail E.,Nifant’Ev, Ilya E.,Churakov, Andrei V.
, p. 769 - 781 (2018)
The structural study of Sc complexes containing dianions of anthracene and tetraphenylethylene should shed some light on the nature of rare-earth metal-carbon bonding. The crystal structures of (18-crown-6)bis(tetrahydrofuran-κO)sodium bis(η6-1,1,2,2-tetraphenylethenediyl)scandium(III) tetrahydrofuran disolvate, [Na(C4H8O)2(C12H24O6)][Sc(C26H20)2]·2C4H8O or [Na(18-crown-6)(THF)2][Sc(η6-C2Ph4)2]·2(THF), (1b), (η5-1,3-diphenylcyclopentadienyl)(tetrahydrofuran-κO)(η6-1,1,2,2-tetraphenylethenediyl)scandium(III) toluene hemisolvate, [Sc(C17H13)(C26H20)(C4H8O)]·0.5C7H8 or [(η5-1,3-Ph2C5H3)Sc(η6-C2Ph4)(THF)]·0.5(toluene), (5b), poly[[(μ2-η3:η3-anthracenediyl)bis(η6-anthracenediyl)bis(η5-1,3-diphenylcyclopentadienyl)tetrakis(tetrahydrofuran)dipotassiumdiscandium(III)] tetrahydrofuran monosolvate], {[K2Sc2(C14H10)3(C17H13)2(C4H8O)4]·C4H8O}n or [K(THF)2]2[(1,3-Ph2C5H3)2Sc2(C14H10)3]·THF, (6), and 1,4-diphenylcyclopenta-1,3-diene, C17H14, (3a), have been established. The [Sc(η6-C2Ph4)2]-complex anion in (1b) contains the tetraphenylethylene dianion in a symmetrical bis-η3-allyl coordination mode. The complex homoleptic [Sc(η6-C2Ph4)2]-anion retains its structure in THF solution, displaying hindered rotation of the coordinated phenyl rings. The1D1H and13C{1H}, and 2D COSY1H-1H and13C-1H NMR data are presented for M[Sc(Ph4C2)2]·xTHF [M = Na and x = 4 for (1a); M = K and x = 3.5 for (2a)] in THF-d8 media. Complex (5b) exhibits an unsymmetrical bis-η3-allyl coordination mode of the dianion, but this changes to a η4 coordination mode for (1,3-Ph2C5H3)Sc(Ph4C2)(THF)2, (5a), in THF-d8 solution. A 45Sc NMR study of (2a) and UV-Vis studies of (1a), (2a) and (5a) indicate a significant covalent contribution to the Sc-Ph4C2 bond character. The unique Sc ate complex, (6), contains three anthracenide dianions demonstrating both a η6-coordination mode for two bent ligands and a μ2-η3:η3-bridging mode of a flat ligand. Each [(1,3-Ph2C5H3)2Sc2(C14H10)3]2-dianionic unit is connected to four neighbouring units via short contacts with [K(THF)2]+ cations, forming a two-dimensional coordination polymer framework parallel to (001).
Synthesis of a Tetraphenyl-Substituted Dihydropentalene and Its Alkali Metal Hydropentalenide and Pentalenide Complexes
Boyt, Stuart M.,Jenek, Niko A.,Sanderson, Hugh J.,Kociok-K?hn, Gabriele,Hintermair, Ulrich
, p. 211 - 225 (2021/11/17)
We report a high-yielding solution phase synthesis of 1,3,4,6-tetraphenyl-dihydropentalene based on a simple annulation reaction of cyclopentadiene with a chalcone. Deprotonative metalation of 1,3,4,6-tetraphenyl-dihydropentalene with alkali metal bases (
Gold-Catalyzed Rearrangement of Alkynyl Donor-Acceptor Cyclopropanes to Construct Highly Functionalized Alkylidenecyclopentenes
Chen, Huiyu,Zhang, Jing,Wang, David Zhigang
, p. 2098 - 2101 (2015/05/13)
A gold-catalyzed 1,7-addition-cyclization-elimination cascade sequence performed on a range of alkynyl-substituted donor-acceptor-type cyclopropanes provides facile entry to highly functionalized exo-alkylidenecyclopentenes under very mild conditions. Iso
A radical-anion chain mechanism following dissociative electron transfer reduction of the model prostaglandin endoperoxide, 1,4-diphenyl-2,3- dioxabicyclo[2.2.1]heptane
Magri, David C.,Workentin, Mark S.
body text, p. 3354 - 3361 (2009/02/05)
The model prostaglandin endoperoxide, 1,4-diphenyl-2,3-dioxabicyclo[2.2.1] heptane (3), was investigated in N,N-dimethylformamide at a glassy carbon electrode using various electrochemical techniques. Reduction of 3 occurs by a concerted dissociative electron transfer (ET) mechanism. Electrolysis at -1.6 V yields 1,3-diphenyl-cyclopentane-cis-1,3-diol in 97% by a two-electron mechanism; however, in competition with the second ET from the electrode, the resulting distonic radical-anion intermediate undergoes a β-scission fragmentation. The rate constant for the heterogeneous ET to the distonic radical-anion is estimated to occur on the order of 2 × 107 s-1. In contrast, electrolyses conducted at potentials more negative than -2.1 V yield a mixture of primary and secondary electrolysis products including 1,3-diphenyl-cyclopentane-cis-1,3-diol, 1,3-diphenyl-1,3-propanedione, trans-chalcone and 1,3-diphenyl-1,3-hydroxypropane by a mechanism involving less than one electron equivalent. These observations are rationalized by a catalytic radical-anion chain mechanism, which is dependent on the electrode potential and the concentration of weak non-nucleophilic acid. A thermochemical cycle for calculating the driving force for β-scission fragmentation from oxygen-centred biradicals and analogous distonic radical-anions is presented and the results of the calculations provide insight into the reactivity of prostaglandin endoperoxides.
Ruthenium-catalyzed cycloisomerization of cis-3-en-1-ynes to cyclopentadiene and related derivatives through a 1,5-sigmatropic hydrogen shift of ruthenium vinylidene intermediates
Datta, Swarup,Odedra, Arjan,Liu, Rai-Shung
, p. 11606 - 11607 (2007/10/03)
We report a new ruthenium-catalyzed cycloisomerization of unactivated cis-3-en-1-ynes, which produces substituted cyclopentadiene and related derivatives. The mechanism of this cyclization is proposed to involve a [1,5]-sigmatropic hydrogen shift of ruthenium-vinylidene intermediates on the basis of deuterium-labeling experiments. Copyright
Deoxygenation of 1,3-Diene 1,4-Endoperoxides by Tin(II) Chloride
Kohmoto, Shigeo,Kasai, Satoru,Yamamoto, Makoto,Yamada, Kazutoshi
, p. 1477 - 1478 (2007/10/02)
The reaction of bicyclic 1,3-diene 1,4-endoperoxides with SnCl2 re-generated the corresponding dienes in 15-70percent yield.The efficiency of the deoxygenation depended on the structure of peroxides.The results were compared with those of Fe(II) as well as Pd(0) assisted reactions.
Response of acidity and magnetic resonance properties to aryl substitution in carbon acids and derived carbanions: 1-Aryl-4-phenylcyclopenta-1,3-dienes. Dependence of ionic structure on aryl substitution
Greifenstein, Linda G.,Lambert, Joseph B.,Nienhuis, Ronald J.,Drucker, George E.,Pagani, Giorgio A.
, p. 7753 - 7761 (2007/10/06)
Monosubstitution on one aryl ring of 1,4-diphenylcyclopenta-1,3-diene provides a probe for studying anion stability, charge density, and ionic structure. We have measured the pKa's of several members of this series in both pure Me2SO
CYCLIC TRIMERIZATION OF ACETYLENES TO FULVENES
Chukhadzhyan, G. A.,Abramyan, Zh. I.,Tonyan, G. M.,Sagradyan, L. I.,Elbakyan, T. S.
, p. 1636 - 1640 (2007/10/02)
The catalytic transformation of acetylene and its derivatives at palladium complexes was investigated.Acetylene, phenylacetylene, and tert-butylacetylene are converted into the fulvene valence isomers of benzene in the presence of cationic bisarene complexes of palladium Pd(AlCl4)2*2C6H6 and Pd(Al3Cl7)2*2C6H6 and also in the presence of Pd(OAc)2 and Pd.
