- A three-step process to facilitate the annulation of polycyclic aromatic hydrocarbons
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A new efficient three-step process to annulate polycyclic aromatic hydrocarbons (PAHs) has been developed, providing access to PAHs with saturated rings that under current chemical methods would be difficult to produce in an efficient manner. This method relies on a palladium-catalyzed cross-coupling reaction of various brominated PAHs with cyclohexanone to yield α-arylated ketones, which are converted to regiospecific vinyl triflates and cyclized by a palladium-catalyzed intramolecular arene-vinyl triflate coupling to produce PAHs with incorporated saturated rings or "tetrahydroindeno-annulated" PAHs.
- Martin, Sara E.,Streeter, Matthew D.,Jones, Laurel L.,Klepfer, Matthew S.,Atmatzidis, Kyriakos,Wille, Kristen D.,Harrison, Sean A.,Hoegg, Edward D.,Sheridan, Heather M.,Kramer, Stephanie,Parrish, Damon A.,Amick, Aaron W.
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p. 8324 - 8330
(2015/03/18)
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- Arylalkene synthesis via decarboxylative cross-coupling of alkenyl halides
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A bimetallic catalyst system generated from readily available palladium(II) and copper(I) salts, 1,10-phenanthroline and tri-1-naphthylphosphine was found to efficiently mediate the decarboxylative cross-coupling of alkenyl bromides and chlorides with aromatic carboxylates. It allows the regiospecific synthesis of a broad range of aryl- and heteroarylalkenes in high yields.
- Tang, Jie,Goossen, Lukas J.
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supporting information
p. 2664 - 2667
(2014/06/09)
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- Selective arylation at the vinylic site of cyclic olefins
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Cyclic olefins usually give Heck products having an aryl ring residing at the allylic or homoallylic position. We describe herein a new method that allows arylation at the vinylic position of various cyclic olefins.
- Wu, Xiaojin,Zhou, Jianrong
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supporting information
p. 4794 - 4796
(2013/06/05)
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- FeCl3/Nal-catalyzed allylic C-H oxidation of arylalkenes with a catalytic amount of disulfide under air
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This paper describes a FeCl3/NaI-catalyzed formal allylic C-H oxidation of arylalkenes using a catalytic amount of disulfide with BnOH and 4-nitroaniline as nucleophiles and air as oxidant to form the corresponding allyl ethers and amines. A possible reaction mechanism has been proposed.
- Huang, Deshun,Wang, Haining,Xue, Fazhen,Shi, Yian
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body text
p. 7269 - 7274
(2011/10/09)
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- A convenient synthesis of 2-naphthylcyclopentanones and 2-naphthylcyclohexanones from 1-naphthylcycloalkenes
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The oxidation of naphthylcycloalkenes with hydrogen peroxide or MCPBA followed by acid catalyzed rearrangement of diol (epoxide), afforded a series of naphthylcycloalkanones in a very simple manner. The conditions allow preparation of naphthylcycloalkanones on a multigram scale. Georg Thieme Verlag Stuttgart.
- Gora, Maciej,Luczynski, Michal K.,Sepiol, Janusz J.
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p. 1625 - 1630
(2007/10/03)
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- Oxidative fragmentation of 1-aryl-1-cycloalkenes using cerium(IV) ammonium nitrate (CAN): Some novel observations
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1-Phenyl-1-cycloalkenes undergo oxidative fragmentation in presence of CAN in methanol, affording 1,n-dicarbonyl compounds as the major products along with 1,2-dimethoxycycloalkanes. The reaction under deoxygenated conditions afforded the latter in good yields. In the presence of azide ion, fragmentation leading to the corresponding cyanoketones was observed whereas with sulfinate only the 1-methoxy-2-sulfonyl cycloalkanes were formed.
- Nair, Vijay,Panicker, Sreeletha B,Thomas, Siji,Santhi,Mathai, Sindhu
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p. 3229 - 3234
(2007/10/03)
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- Enantioselective protonation of samarium enolates derived from α- heterosubstituted ketones and lactone by SmI2-mediated reduction
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SmI2-mediated reductive cleavage of α-heterosubstituents of α-alkyl or α-aryl ketones and lactone gave the corresponding 'thermodynamic samarium enolates'. Enantioselective protonation of the samarium enolates with C2- symmetric chiral diols afforded the corresponding ketones and lactone in moderate to high enantioselectivities.
- Nakamura, Yutaka,Takeuchi, Seiji,Ohgo, Yoshiaki,Yamaoka, Makoto,Yoshida, Akihiro,Mikami, Koichi
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p. 4595 - 4620
(2007/10/03)
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- Nickel-catalyzed cross-couplings of cyclohexenyl phosphate and arylboronic acids
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The Nickel-catalyzed cross-coupling reaction of cyclohexenylphosphate with a variety of arylboronic acids is described here for the first time. This methodology opens the door to other palladium or nickel-catalyzed coupling reactions involving vinyl phosphates.
- Nan, Yang,Yang, Zhen
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p. 3321 - 3324
(2007/10/03)
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- THE SYNTHESIS OF SOME 1-NAPHTHYLCYCLOALKANOLS AND 1-NAPHTHYLCYCLOALKENES
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1-Naphthylcycloalkanols having 3, 4, 5, 6, 7, 12 and 15 ring carbons were synthesized from corresponding cyclic ketones and 1-naphthylbromide using Grignard reaction. The dehydration products of these naphthylcycloalkanols were obtained. All the products were identified by means of IR- and 1H-NMR spectra.
- Guenaydin, Keriman
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p. 925 - 930
(2007/10/03)
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- Triplet State of α-Naphthylethylene Derivatives. Structural Effects on the Equilibrium between Planar and Perpendicular Triplet Conformations
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The properties of the triplet state of a series of 1-(α-naphthyl)ethylene derivatives have been studied by laser flash photolysis.The geometry of the triplet state has been determined from the T-T absorption spectra, the lifetime values, and the quenching rate constants by oxygen, stilbene, and ferrocene.The triplet state can be either planar (nontwisted double bond), when the ethylenic moiety is inserted into a small ring, or perpendicular (double bond twisted by 90 deg), when the planar geometry is disfavored by a strong steric hinderance.However, in most cases, there is a fast equilibrium between the planar and perpendicular triplets.These two geometries are very close in energy and therefore the equilibrium can be greatly modified by small changes in the molecular structure such as an alkyl substitution.By comparison of the triplet state of 1-(α-naphthyl)-1-phenylethylene with that of other 1-aryl-1-phenylethylenes, an experimental correlation is found between the percentage of planar triplet and the triplet energy of the aryl group.
- Lazare, Sylvain,Bonneau, Roland,Lapouyade, Rene
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- Hydrodesulfuration de molecules polycycliques aromatiques sulfurees sur catalyseur NiMo/γAl2O3: Etude du benzo(b)naphtothiophene et du tetrahydro-8,9,10,11 benzo(b)naphtothiophene
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The hydrodesulfurisation of two aromatic polycyclic compounds has been studied on sulfurised NiMo/Al2O3 catalyst at 250 deg C, 40 atm in dodecane: benzo(b)naphthothiophen and 8,9,10,11-tetrahydrobenzo(b)naphthothiophen.For these two molecules, there always is competition between the different processes, hydrogenation of the thiophen double bond, hydrogenation of the aromatic (naphthenic) part and desulfurisation.This result is very different from those found for benzo(b)thiophen, where the first step was hydrogenation of the olefinic double bond prior to desulfurisation, and for dibenzothiophen, where desulfurisation (hydrogenolysis) takes place prior to hydrogenation.The main consequence of this behaviour is that the heavier the sulfur compounds the more important the consumption of hydrogen will be in the overall hydrotreatment process on this catalyst because hydrogenation of aromatic rings competes with hydrogenolysis.
- Guida, Alain,Levache, Denis,Geneste, Patrick
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p. 170 - 174
(2007/10/02)
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