Efficient Synthesis of 4,5,9,10-Tetrahydropyrene:  A Useful Synthetic Intermediate for the Synthesis of 2,7-Disubstituted Pyrenes

Connor, Daniel M.; Allen, Scott D.; Collard, David M.; Liotta, Charles L.; Schiraldi, David A.

doi:10.1021/jo990257j

Cited by 41 publications

(31 citation statements)

References 30 publications

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“…We note that the synthesis of 2‐(amino)pyrene has before been reported by Bolton in 1964, using an indirect route through the reduction of pyrene to 4,5,9,10‐tetrahydropyrene (THP), nitration at the 2‐position, re‐aromatization and reduction to 2‐(amino)pyrene with an overall yield of about 25 %. In addition to the low yield, this route suffers from the fact that the synthesis of THP involves high pressures of H 2 , long reaction times, large amounts of catalyst, and prior purification of the commercial pyrene with RANEY nickel . Our new synthetic route through the initial iridium‐catalyzed C−H borylation reaction consists of only two steps, with overall yields of 51 % for 5 and 76 % for 1 , starting from commercial pyrene.…”

Section: Resultsmentioning

confidence: 99%

Pyrene Molecular Orbital Shuffle—Controlling Excited State and Redox Properties by Changing the Nature of the Frontier Orbitals

Merz

Fink

Friedrich

et al. 2017

Chemistry A European J

100

120

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We show that by judicious choice of substituents at the 2- and 7-positions of pyrene, the frontier orbital order of pyrene can be modified, giving enhanced control over the nature and properties of the photoexcited states and the redox potentials. Specifically, we introduced a julolidine-like moiety and Bmes (mes=2,4,6-Me C H ) as very strong donor (D) and acceptor (A), respectively, giving 2,7-D-π-D- and unsymmetric 2,7-D-π-A-pyrene derivatives, in which the donor destabilizes the HOMO-1 and the acceptor stabilizes the LUMO+1 of the pyrene core. Consequently, for 2,7-substituted pyrene derivatives, unusual properties are obtained. For example, very large bathochromic shifts were observed for all of our compounds, and unprecedented green light emission occurs for the D/D system. In addition, very high radiative rate constants in solution and in the solid state were recorded for the D-π-D- and D-π-A-substituted compounds. All compounds show reversible one-electron oxidations, and Jul Pyr exhibits a second oxidation, with the largest potential splitting (ΔE=440 mV) thus far reported for 2,7-substituted pyrenes. Spectroelectrochemical measurements confirm an unexpectedly strong coupling between the 2,7-substituents in our pyrene derivatives.

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Section: Resultsmentioning

confidence: 99%

Pyrene Molecular Orbital Shuffle—Controlling Excited State and Redox Properties by Changing the Nature of the Frontier Orbitals

Merz

Fink

Friedrich

et al. 2017

Chemistry A European J

100

120

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“…Dimethyl isophthalate, dimethyl phthalate, dimethyl 1,5‐naphthoate, and dimethyl 1,8‐naphthoate were purchased from Aldrich Chemical Co. (Milwaukee, WI) and used without further purification. Dimethyl 2,6‐anthracenate,13, 14 dimethyl 1,8‐anthracenate,15 and dimethyl 2,7‐pyrene dicarboxylate16 were prepared by the literature method 16. The structures of the various comonomer units are summarized in Table I.…”

Section: Methodsmentioning

confidence: 99%

Oxygen‐barrier properties of polyethylene terephthalate modified with a small amount of aromatic comonomer

Polyakova

Connor

Collard

et al. 2001

J Polym Sci B Polym Phys

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The oxygen‐barrier properties of amorphous copolyesters based on ethylene terephthalate with 10%, or less, of an acid comonomer were examined. Comonomer units were isophthalate, phthalate, 1,5‐naphthalate, 1,8‐naphthalate, 2,6‐naphthalate, 1,8‐anthracenate, 2,6‐anthracenate, and 2,7‐pyrenate. Even 2.5 mol % comonomer significantly affected the permeability. Linear comonomers decreased the permeability. In contrast, small amounts of a kinked comonomer increased the permeability. However, increasing the amount of kinked comonomer further (gradually) decreased permeability P below that of polyethylene terephthalate. Generally, comonomer affected solubility S less than diffusivity D; therefore, changes in P reflected primarily changes in D. The solubility and diffusivity depended on copolymer composition in accordance with static and dynamic free‐volume concepts of gas permeability in glassy polymers. The solubility correlated with the amount of free volume, as determined by the glass‐transition temperature. This study also explored the relationship of dynamic free volume, which determines D, to thermally accessible segmental motions of the polymer chain. The effect of comonomer on D correlated with the intensity of the gauche component of the subambient γ relaxation. Changes in the fraction of gauche‐glycol conformations resulting from copolymerization were confirmed by Fourier transform infrared spectroscopy. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1900–1910, 2001

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“…[14] In addition, 2,7-substituted pyrenes also represent attractive scaffolds on which to base the design of conjugated oligomers with a well defined straight shape. [23] These, however, are much less soluble, unless alkyl chains are introduced at the 4-and 9-positions, and substitution at the 2,7-positions of pyrene requires tedious indirect routes., [24,25] Moreover, the molecular orbital coefficients of the 2-and 7-centers are nearly zero, which induces electronic decoupling of the pyrene ring with the π-delocalized substituent. Although this peculiar property may impart new electronic features to the conjugated rods, it has scarcely been investigated so far.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Photophysical Properties of a Highly Fluorescent Ditopic Ligand Based on 1,6‐Bis(ethynyl)pyrene as Central Aromatic Core

Leroy‐Lhez

Fagès

2005

Eur J Org Chem

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Efficient Synthesis of 4,5,9,10-Tetrahydropyrene: A Useful Synthetic Intermediate for the Synthesis of 2,7-Disubstituted Pyrenes

Cited by 41 publications

References 30 publications

Pyrene Molecular Orbital Shuffle—Controlling Excited State and Redox Properties by Changing the Nature of the Frontier Orbitals

Pyrene Molecular Orbital Shuffle—Controlling Excited State and Redox Properties by Changing the Nature of the Frontier Orbitals

Oxygen‐barrier properties of polyethylene terephthalate modified with a small amount of aromatic comonomer

Synthesis and Photophysical Properties of a Highly Fluorescent Ditopic Ligand Based on 1,6‐Bis(ethynyl)pyrene as Central Aromatic Core

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