- Synthesis and Properties of Partially Saturated Fluorenyl-Derived [n]Helicenes Featuring an Overcrowded Alkene
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The straightforward, multigram-scale synthesis of the partially saturated H6-fluoreno[n]helicenes (n=5 or 7) featuring a central, overcrowded alkene is described. The key cyclization step was based on an intramolecular McMurry reaction from the corresponding 1,5-diketones. Chiral stationary phase HPLC analysis and isomer separation indicate that each helicenic compound is constituted of three diastereoisomers at room temperature, i. e. the configurationally stable (R,R,P)/(S,S,M) pair of enantiomers and an apparently achiral compound resulting from the rapid interconversion between the (R,S,P) and (S,R,M) enantiomers. The partially saturated H6-fluoreno[n]helicenes are oxidatively aromatized to give an efficient access to the corresponding fluoreno[n]helicenes. The chiroptical properties (vibrational and electronic circular dichroism) of the chiral, enantiopure compounds have been measured and analyzed by quantum-chemical calculations, confirming their helicoidal nature.
- Pallova, Lenka,Gauthier, Etienne S.,Abella, Laura,Jean, Marion,Vanthuyne, Nicolas,Dorcet, Vincent,Vendier, Laure,Autschbach, Jochen,Crassous, Jeanne,Bastin, Stéphanie,César, Vincent
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- TRANSITION METAL COMPOUND FOR OLEFIN POLYMERIZATION CATALYST, OLEFIN POLYMERIZATION CATALYST COMPRISING SAME AND POLYOLEFIN POLYMERIZED USING SAME
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Provided is a transition metal compound, represented by chemical formula 1, for an olefin polymerization catalyst. The details of chemical formula 1 are the same as those defined in the specification.
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Paragraph 0054-0055
(2021/06/11)
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- Gold(I) carbenes by retro-buchner reaction: Generation and fate
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The fate of the aryl gold(I) carbenes generated by retro-Buchner reaction of ortho-substituted 7-aryl-1,3,5-cycloheptatrienes is dependent on the constitution of the ortho substituent. Indenes and fluorenes are obtained by intramolecular reaction of highly electrophilic gold(I) carbenes with alkenes and arenes. According to density functional theory calculations, the gold-catalyzed retro-Buchner process occurs stepwise, although the two carbon-carbon cleavages occur on a rather flat potential energy surface.
- Wang, Yahui,McGonigal, Paul R.,Herle, Bart,Besora, Maria,Echavarren, Antonio M.
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p. 801 - 809
(2014/02/14)
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- DIBENZO[C,G]FLUORENE COMPOUND AND ORGANIC LIGHT-EMITTING DEVICE USING SAME
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An organic light-emitting device is provided which efficiently emits light with high brightness and has durability. The organic light-emitting device includes a dibenzo[c,g]fluorene compound having two dibenzo[c,g]fluorene skeletons, and has an organic compound layer containing the dibenzo[c,g]fluorene compound.
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Page/Page column 11; 40; 42
(2010/06/11)
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- DIBENZO[c,g]FLUORENE COMPOUND AND AN ORGANIC LIGHT-EMITTING DEVICE USING THE SAME
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An organic light-emitting device which has high emission efficiency and high durability even at low drive voltage is provided. An organic light-emitting device including an anode, a cathode, and an organic compound layer which is interposed between the anode and the cathode, wherein the organic compound layer include at least one dibenzo[c,g]fluorene compound represented by the following General Formula (1).
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Page/Page column 57
(2009/12/23)
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- On the di-1-naphthylcarbene-dibenzofluorene rearrangement and the ethylenization of diarylcarbinols
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Solution-spray flash vacuum thermolysis of di-1-naphthyldiazomethane (9) results in the formation of dibenzo[c,g]fluorene (12), formed via a carbene- carbene rearrangement of di-1-naphthylcarbene (10). The isomeric dibenzo[α,i]fluorene (11) claimed by Franzen and Joschek (Liebigs Ann. Chem. 1960, 633, 7) is not formed, and no dibenzofluorene is formed on thermolysis in boiling naphthalene. 11 is formed on dehydration of di-1-naphthylcarbinol (14) with phosphoric acid, but the claimed tetra-1-naphthylethylene (13) is not formed, and the so-called ethylenization of diarylcarbinols is cast in doubt generally. The compound previously believed to be 13 is 13-[di(1- naphthyl)methyl]-dibenzo[α,i]fluorene (22). The alleged cleavage of 13 into two molecules of carbene 10 is unsubstantiated.
- Regimbald-Krnel, Michele,Wentrup, Curt
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p. 8417 - 8423
(2007/10/03)
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- A New General Synthesis of Polycyclic Aromatic Compounds Based on Enamine Chemistry
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Alkylation of enamines and enamine salts by benzylic and (β-haloethyl)aryl halides, respectively, followed by acidic cyclodehydration and dehydrogenation provides an efficient synthetic approach to a wide range of polycyclic aromatic compounds of diverse structural types.Specific polycyclic hydrocarbons synthesized by this route include benzo- and benzofluorene, 7H-dibenzo-, 13H-dibenzo-, and 13H-dibenzofluorene, 15H-tribenzofluorene, dibenzochrysene, benzopentaphene, indenofluorene, fluorenofluorene, octahydrodibenzanthracene, dibenzanthracene, octahydrodibenzanthracene, dibenzanthracene, picene, benzopicene, 1H-benzaceanthrylene, and 4H-cyclopentachrysene.This method with appropriate modifications appears to be potentially broader in scope than established traditional methods of polycyclic hydrocarbon synthesis.
- Harvey, Ronald G.,Pataki, John,Cortez, Cecilia,Raddo, Pasquale Di,Yang, ChengXi
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p. 1210 - 1217
(2007/10/02)
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