163271-80-5Relevant academic research and scientific papers
Straightforward Synthesis of 5-Bromopenta-2,4-diynenitrile and Its Reactivity Towards Terminal Alkynes: A Direct Access to Diene and Benzofulvene Scaffolds
Kerisit, Nicolas,Toupet, Lo?c,Larini, Paolo,Perrin, Lionel,Guillemin, Jean-Claude,Trolez, Yann
, p. 6042 - 6047 (2015)
The high-yielding synthesis of 5-bromopenta-2,4-diynenitrile (BrC5N) was achieved for the first time. Its reactivity with triisopropylsilylacetylene and triisopropylsilylbutadiyne in the presence of copper and palladium as co-catalysts and diisopropylamine was evaluated. It revealed an unprecedented cascade reaction leading to a diene in one case and to a benzofulvene in the other case, with a unique structure. Both of them were characterized by X-ray crystallography, among other techniques. The mechanism of the reaction leading to the diene was investigated experimentally. Theoretical calculations at the DFT level suggest that the mechanism leading to the benzofulvene relies on a hexa-dehydro Diels-Alder (HDDA)-type of mechanism. This work constitutes an example of an unanticipated reactivity leading to an important increase of chemical complexity.
Total Synthesis of the Spliceosome Modulator Pladienolide B via Asymmetric Alcohol-Mediated syn- and anti-Diastereoselective Carbonyl Crotylation
Yoo, Minjin,Krische, Michael J.
, (2021)
The potent spliceosome modulator pladienolide B, which bears 10 stereogenic centers, is prepared in 10 steps (LLS). Asymmetric alcohol-mediated carbonyl crotylations catalyzed by ruthenium and iridium that occur with syn- and anti-diastereoselectivity, re
Synthesis of Polyynes Using Dicobalt Masking Groups
Kohn, Daniel R.,Gawel, Przemyslaw,Xiong, Yaoyao,Christensen, Kirsten E.,Anderson, Harry L.
, p. 2077 - 2086 (2018)
Extended triisopropylsilyl end-capped polyynes have been prepared from the corresponding tetracobalt complexes by removing the complexed dicobalt tetracarbonyldiphenylphosphinomethane (Co2(CO)4dppm) moieties. Unmasking of this "masked alkyne equivalent" was achieved under mild conditions with elemental iodine at room temperature, making it possible to obtain fragile polyynes with up to 20 contiguous sp-hybridized carbon atoms. The Co2(CO)4dppm moiety has a strong geometric and steric effect on the polyyne but does not have a marked electronic effect on the terminal alkyne, as indicated by NMR and IR spectroscopy, density functional theory calculations, and X-ray crystallography. An unusual "alkyne hopping" migration of the dicobalt group was noticed as a minor side reaction during copper-catalyzed Eglinton coupling.
Covalent Cobalt Porphyrin Framework on Multiwalled Carbon Nanotubes for Efficient Water Oxidation at Low Overpotential
Jia, Hongxing,Sun, Zijun,Jiang, Daochuan,Du, Pingwu
, p. 4586 - 4593 (2015)
A noble-metal-free, efficient, and robust catalyst made of Earth-abundant elements for water oxidation is vital to achieve practical water splitting for future clean energy production. Herein, we report the synthesis of multilayer covalent cobalt porphyrin framework on multiwalled carbon nanotubes ((CoP)n-MWCNTs) to produce a highly active electrocatalyst for water oxidation. A linear sweep voltammetry curve showed that a catalytic current density of 1.0 mA/cm2 can be achieved under a potential of only 1.52 V (vs RHE, corresponding to an overpotential of only 0.29 V) in alkaline solution at pH 13.6. Such an onset potential is much lower than that of cobalt porphyrin monomer (CoP-TIPS) and pure MWCNTs. In addition, the chronopotentiometry data confirmed its excellent catalytic activity and suggested that the (CoP)n-MWCNTs catalyst has good durability for water oxidation catalysis. A Tafel slope of 60.8 mV per decade was obtained by bulk electrolysis measurement, and the Faradaic efficiency of oxygen production was >86%. (Chemical Equation Presented).
Novel one-pot synthesis of 5-alkenyl-15-alkynylporphyrins and their derivatisation to a butadiyne-linked benzoporphyrin dimer
Yamada, Hiroko,Kushibe, Kayo,Okujima, Tetsuo,Uno, Hidemitsu,Ono, Noboru
, p. 383 - 385 (2006)
5-Alkenyl-15-alkynylporphyrins have been obtained unexpectedly by [2 + 2] acid-catalyzed condensation of dipyrrylmethane and TMS propynal in addition to 5,15-dialkynylporphyrin, and the unsymmetrical porphyrin can be converted to a butadiyne-linked dimer
The first α-fluoroallenylphosphonate, the synthesis of conjugated fluoroenynes, and the stereoselective synthesis of vinylfluorophosphonates using a new multifunctional fluorine-containing building block
Zapata, Antonio J.,Gu, Yonghong,Hammond, Gerald B.
, p. 227 - 234 (2000)
Limitations on current methodologies for the introduction of CF2 and CFH in complex α-fluorophosphonates led to the synthesis of a fluorine- containing building block TIPS-C?CCFXP(O)(OEt)2, where X = H or F. This multifunctional fluorine synthon reacts with carbonyl compounds under WHE conditions to give high yields of fluorinated conjugated enynes and enediyne. When X = F, trapping of the desilylated anion with an electrophile after TIPS removal provided exclusive access to γ-substituted derivatives of α- fluorophosphonates. When X = H, TBAF deprotection of the silyl group yields H2C=C=CFP(O)(OEt)2 through an allenyl-propargyl resonance stabilized anion. The allene moiety has been used as template in the stereoselective synthesis of α-fluoro-β,γ-diiodopropenyl phosphonate, via electrophilic iodination, and α-fluoro-γ-amino-α,β-unsaturated phosphonates, including unsaturated phosphononucleosides, by nucleophilic displacement of an allylic iodide. Hydroamination of H2C=C=CFP(O)(OEt)2 using secondary amines produced (Z)- α-fluoroenaminophosphonates, whereas Diels-Alder cycloaddition with cyclopentadiene provides the corresponding exocyclic vinylfluorophosphonate.
carbo-Naphthalene: A Polycyclic carbo-Benzenoid Fragment of α-Graphyne
Cocq, Kévin,Saffon-Merceron, Nathalie,Coppel, Yannick,Poidevin, Corentin,Maraval, Valérie,Chauvin, Remi
, p. 15133 - 15136 (2016)
A ring carbo-mer of naphthalene, C32Ar8(Ar=p-n-pentylphenyl), has been obtained as a stable blue chromophore, after a 19-step synthetic route involving methods inspired from those used in the synthesis of carbo-benzenes, or specifically devised for the present target, like a double Sonogashira-type coupling reaction. The last step is a SnCl2/HCl-mediated reduction of a decaoxy-carbo-decalin, which is prepared through successive [8+10] macrocyclization steps. Two carbo-benzene references are also described, C18Ar6and o-C18Ar4(C≡C-SiiPr3)2. The carbo-naphthalene bicycle is locally aromatic according to structural and magnetic criteria, as revealed by strong diatropic ring current effects on the deshielding of1H nuclei of the Ar groups and on the negative value of the DFT-calculated NICS at the center of the C18rings (?12.8 ppm). The stability and aromaticity of this smallest fused molecular fragment of α-graphyne allows prediction of the same properties for the carbon allotrope itself.
Metallated porphyrins containing lead(II), copper(II) or zinc(II)
John Plater,Aiken, Stuart,Bourhill, Grant
, p. 2415 - 2422 (2002)
A series of ethynyl and aryl substituted porphyrins and the corresponding metallated derivatives have been synthesised and characterised.
Substituted Tetraethynylethylene–Tetravinylethylene Hybrids
Connor, Kieran P. E.,Horvath, Kelsey L.,Magann, Nicholas L.,Sherburn, Michael S.,Sowden, Madison J.,Westley, Erin
supporting information, p. 977 - 986 (2022/02/03)
A general synthetic approach to molecular structures that are hybrids of tetraethynylethylene (TEE) and tetravinylethylene (TVE) is reported. The synthesis permits the controlled preparation of many previously inaccessible structures, including examples w
Total Synthesis of Leiodermatolide A via Transfer Hydrogenative Allylation, Crotylation, and Propargylation: Polyketide Construction beyond Discrete Allyl- or Allenylmetal Reagents
Krische, Michael J.,Roane, James,Siu, Yuk-Ming
supporting information, p. 10590 - 10595 (2021/07/28)
The total synthesis of leiodermatolide A was accomplished in 13 steps (LLS). Transfer hydrogenative variants of three carbonyl additions that traditionally rely on premetalated reagents (allylation, crotylation, and propargylation) are deployed together i
