Synthesis of Areno-Condensed [24]Annulenes

Meier, Herbert; Fetten, Michael; Schnorpfeil, Christoph

doi:10.1002/1099-0690(200102)2001:4<779::aid-ejoc779>3.0.co;2-j

Cited by 12 publications

(12 citation statements)

References 19 publications

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“…Compound 2,p repared by tosylation of diethylene glycol monomethyl ether 1, [55] wasr eactedw ith hydroquinone in ad ouble Williamsonr eaction to afford the intermediate 3 in good yield. [56] Subsequent diiodination of 3 by using iodine in conjunction with KIO 3 in acetic acid afforded the diiodo building block 4 in satisfactory yield after recrystallization. [57] This protocolh as been scaled up andp rovides an easy access to grams (30 g) of intermediate 4 (Scheme 1).…”

Section: Synthesis Of the Target Compoundsmentioning

confidence: 99%

A Bis‐Manganese(II)–DOTA Complex for Pulsed Dipolar Spectroscopy

et al. 2016

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High-spin gadolinium(III) and manganese(II) complexes have emerged as alternatives to standard nitroxide radical spin labels for measuring nanometric distances by using pulsed electron-electron double resonance (PELDOR or DEER) at high fields/frequencies. For certain complexes, particularly those with relatively small zero-field splitting (ZFS) and short distances between the two metal centers, the pseudosecular term of the dipolar coupling Hamiltonian is non-negligible. However, in general, the contribution from this term during conventional data analysis is masked by the flexibility of the molecule of interest and/or the long tethers connecting them to the spin labels. The efficient synthesis of a model system consisting of two [Mn(dota)](2-) (MnDOTA; DOTA(4-) =1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) directly connected to the ends of a central rodlike oligo(phenylene-ethynylene) (OPE) spacer is reported. The rigidity of the OPE is confirmed by Q-band PELDOR measurements on a bis-nitroxide analogue. The Mn(II) -Mn(II) distance distribution profile determined by W-band PELDOR is in reasonable agreement with one simulated by using a simple rotamer analysis. The small degree of flexibility arising from the linking MnDOTA arm appears to outweigh the contribution from the pseudosecular term at this interspin distance. This study illustrates the potential of MnDOTA-based spin labels for measuring fairly short nanometer distances, and also presents an interesting candidate for in-depth studies of pulsed dipolar spectroscopy methods on Mn(II) -Mn(II) systems.

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Section: Synthesis Of the Target Compoundsmentioning

confidence: 99%

A Bis‐Manganese(II)–DOTA Complex for Pulsed Dipolar Spectroscopy

et al. 2016

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“… [ 81 ] I 2 , Methyloxirane, Toluene, hν = ? [ 82 ] I 2 , Methyloxirane, Benzene, hν = 40 h [ 83 ] I 2 , Methyloxirane, Light petroleum, hν = 2 h [ 84 ] I 2 , Epoxybutane, Toluene, hν = 1.5 h [ 23 ] I 2 , Epoxybutane, Benzene, hν = 2 h [ 85 ] I 2 , Methyloxirane, Cyclohexane, hν = 50 h [ 86 ] I 2 , Epoxybutane, Benzene, hν = 8 h …”

Section: Appendixmentioning

confidence: 99%

Photochemical Oxidative Cyclisation of Stilbenes and Stilbenoids—The Mallory-Reaction

2010

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After Mallory described in 1964 the use of iodine as catalyst for the photochemical cyclisation of stilbenes, this reaction has proven its effectiveness in the synthesis of phenanthrenes, other PAHs and phenacenes with a surprisingly large selection of substituents. The “early age” of the reaction was reviewed by Mallory in 1984in a huge chapter in the Organic Reactions series, but the development has continued. Alternative conditions accommodate more sensitive substituents, and isomers can be favoured by sacrificial substituents. Herein the further developments and applications of this reaction after 1984 are discussed and summarized.

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“…Analogous reaction sequences can be used for the preparation of all-cis-tribenzo[a,e,i] [12]annulene 25d and all-cis-pentabenzo[a,e,i,m,q] [20]annulene 32a, 33 which are drawn in Scheme 3 in the (also for 16c) more realistic crown conformation. Further areno-condensed [18]-and [24]annulenes, which were prepared by Siegrist reactions 23,24,[27][28][29][30][31] Synthesis 2002, No. 9, 1213-1228 ISSN 0039-7881 © Thieme Stuttgart • New York…”

Section: Pinacol Coupling Followed By the Corey-winter Proceduresmentioning

confidence: 99%

Areno-Condensed Annulenes - Extended Discotic Mesogens

Meier¹

2002

Synthesis

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n]Annulenes (n ³12) condensed with 2-4 aromatic ring systems (benzenes, naphthalenes, anthracenes, phenanthrenes, chrysenes, pyrenes) can be prepared by cyclocondensation reactions or ring transformations. Due to the local arene aromaticity, the molecules can be regarded as aromatic islands, which are connected by olefinic bridges. The compounds are non-planar, but the majority of the systems shows a fast inversion of the central macrocyclic ring, so that the molecules appear on average as large planar discs, which consist of extended p systems. The aggregation tendency (p stacking) of the compounds can be strengthened by the attachment of flexible saturated chains on the periphery. The discs represent then mesogens for columnar (or nematic) discotic LC phases. Because of the stilbenoid character, the compounds show a variety of interesting photophysical and photochemical properties. They can be applied in photoconductive liquid crystalline phases Col h and in radiation-induced imaging techniques.

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Synthesis of Areno-Condensed [24]Annulenes

Abstract: 24]Annulenes condensed with three phenanthrene units (11a−d) or with three chrysene ring systems (22) were prepared by multi-step syntheses. The cyclic condensation reaction in the final step led to highly symmetrical compounds. Long flexible alkoxy groups attached to the periphery en-

Cited by 12 publications

References 19 publications

A Bis‐Manganese(II)–DOTA Complex for Pulsed Dipolar Spectroscopy

A Bis‐Manganese(II)–DOTA Complex for Pulsed Dipolar Spectroscopy

Photochemical Oxidative Cyclisation of Stilbenes and Stilbenoids—The Mallory-Reaction

Areno-Condensed Annulenes - Extended Discotic Mesogens

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