Synthesis and metalation of some phenalenothiophenes and a fused benzo derivative

MacDowell, D. W. H.; Jourdenais, Richard A.; Naylor, Ralph F.; Paulovicks, G. E.

doi:10.1021/jo00817a024

Cited by 10 publications

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“…Large phenalenoid structures with ortho -fused heterocycles have been explored to a limited extent. A range of phenalene-1-one derivatives have nevertheless been reported, including heterofused benzo[ de ]anthracen-3-ones C38.1 and C38.2 (Chart ), and benzanthrones (benzo[ de ]anthracen-7-ones), containing pyridine ( C38.3 – 4 , C38.5 ), pyridinone ( C38.6 – 7 ), imidazole ( C38.8 , C38.9 , C38.11 – 12 ), oxazole ( C38.10 ), and indole ( C38.13 ) moieties. Fluorescent anthra[9,1- gh ]quinoline dyes C38.5 , obtained in a Skraup synthesis, were shown to have a very good orientation parameter in nematic liquid crystal ( S A = 0.64–0.67), indicating a high potential for applications in display technology …”

Section: Phenalenoidsmentioning

confidence: 99%

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

et al. 2016

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Two-dimensionally extended, polycyclic heteroaromatic molecules (heterocyclic nanographenes) are a highly versatile class of organic materials, applicable as functional chromophores and organic semiconductors. In this Review, we discuss the rich chemistry of large heteroaromatics, focusing on their synthesis, electronic properties, and applications in materials science. This Review summarizes the historical development and current state of the art in this rapidly expanding field of research, which has become one of the key exploration areas of modern heterocyclic chemistry.

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Section: Phenalenoidsmentioning

confidence: 99%

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

et al. 2016

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“…The chosen mode of ring fusion has one heterocycle double bond aligned with the methylcyclopentenes of these cyclopentadienoid-like systems since b-fusion results in preferential metalation with n- BuLi at the desired active methylene group and also improves anionic delocalization relative to c-fused heterocyclic nuclei . Electronic and steric ligand effects were investigated for sulfur and nitrogen heteroatoms and with the interchanging of hydrogen atoms and methyl groups adjacent to ( 3 , 4) and on the pendant phenyl rings ( 5 − 7 ), respectively (Chart ).…”

Section: Introductionmentioning

confidence: 99%

Chiral Ansa Metallocenes with Cp Ring-Fused to Thiophenes and Pyrroles: Syntheses, Crystal Structures, and Isotactic Polypropylene Catalysts

Ewen¹,

Elder

Jones

et al. 2001

J. Am. Chem. Soc.

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Syntheses, crystal structures, and polymerization data for new isospecific metallocenes (heterocenes) having cyclopentenyl ligands b-fused to substituted thiophenes (Tp) and pyrroles (Pyr) are reported. The C2- and C1-symmetric heterocenes are dimethylsilyl bridged, have methyl groups adjacent to the bridgehead carbon atoms, and have aryl substituents protruding in the front. rac-Me2Si(2,5-Me2-3-Ph-6-Cp[b]Tp)2ZrCl2/MAO (MAO = methyl alumoxanes) is the most active metallocene catalyst for polypropylene reported to date. rac-Me2Si(2,5-Me2-3-Ph-6-Cp[b]Tp)2ZrCl2 and rac-Me2Si(2,5-Me2-1-Ph-4-Cp[b]Pyr)2ZrCl2 have the same structure, and the former is 6 times more active, produces half the total enantiofacial errors, and is 3.5 times less regiospecific in propylene polymerizations at the same conditions. rac-Me2Si(2-Me-4-Ph-1-Ind)2ZrCl2/MAO is 3.5 times lower in activity than rac-Me2Si(2,5-Me2-3-Ph-6-Cp[b]Tp)2ZrCl2 catalyst, and while the former is the more stereospecific and the less regiospecific, the sum of these two enantioface errors is the same for both species. Fine-tuning the heterocene sterics by changing selected hydrogen atoms on the ligands to methyl groups influenced their catalyst activities, stereospecificites, regiospecificites, and isotactic polypropylene (IPP) Mw. Thus, both substituting a hydrogen atom adjacent to the phenyl ring with a methyl group on an azapentalenyl ligand system and replacing one and then two hydrogens on the phenyl ring with methyls on thiopentalenyl ligands provided increased polymer Tm and Mw with increasing ligand bulk. Polymer molecular weights are sensitive to and inversely proportional to MAO concentration, and the catalyst activities increase when hydrogen is added for molecular weight control. The polymer Tm values with the thiopentalenyls as TIBAL/[Ph3C][B(C6F5)4] systems were higher than with MAO as catalyst activator. A racemic C1, pseudo-meso complex with a hybrid dimethylsilyl-bridged 2-Me-4-Ph-1-Ind/2,5-Me2-4-Ph-1-Cp[b]Pyr ligand produced the first sample of IPP with all the steric pentad intensities fitting the enantiomorphic site control model. Speculative mechanistic considerations are offered regarding electronic effects of the heteroatoms and steric effects of the ligand structures, the preferred phenyl torsion angles, and anion effects.

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“…1-(2'-thieny1)-4-(3"-thieny1)-1,3butadiene (12) as before gave a mixture of products, inseparable even by vapor phase chromatography. As shown in Scheme 5, photocyclization-oxidation of 12 can occur t o the 3' position of the 1-thienyl group to give 11 and to the 2" position of the 4-thienyl group t o give 7-(2'-thienyl)benzo[b]thiophene (13).…”

mentioning

confidence: 99%

Photocyclization Reactions of Aryl Polyenes. VII. The Photocyclization of 1-Phenyl-4-thienyl- and 1,4-Dithienyl-1,3-butadienes

Leznoff¹,

Lilie²,

Manning³

1974

Can. J. Chem.

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The photocyclization–oxidation reaction of 1-phenyl-4-(2′-thienyl)-1,3-butadiene gave 4-phenyl-benzo[b]thiophene. Similarly, irradiation of 1-phenyl-4-(3′-thienyl)-l,3-butadiene gave 7-phenylbenzo-[b]thiophene. Thus, photocyclization occurs exclusively to the thiophene ring. Irradiation of 1,4-di(2′-thienyl)-1,3-butadiene and 1,4-di(3′-thienyl)-1,3-butadiene yielded 4-(2′-thienyl)benzo[b]thiophene and 7-(3′-thienyl)benzo[b]thiophene, respectively. Photocyclization of 1-(2′-thienyl)-4-(3″-thienyl)-1,3-butadiene gave an inseparable mixture of 4-(3′-thienyl)benzo[b]thiophene and 7-(2′-thienyl)benzo[b]thiophene.

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Synthesis and metalation of some phenalenothiophenes and a fused benzo derivative

Cited by 10 publications

References 0 publications

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

Chiral Ansa Metallocenes with Cp Ring-Fused to Thiophenes and Pyrroles: Syntheses, Crystal Structures, and Isotactic Polypropylene Catalysts

Photocyclization Reactions of Aryl Polyenes. VII. The Photocyclization of 1-Phenyl-4-thienyl- and 1,4-Dithienyl-1,3-butadienes

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