ChemInform Abstract: METHYLENE‐BRIDGED (4N + 2)ANNULENES BY AN ASSEMBLY PRINCIPLE

Vogel, Emanuel; Deger, Hans M.; Sombroek, Johannes; Palm, J.; Wagner, Arwed; Lex, J.

doi:10.1002/chin.198016142

Cited by 2 publications

(2 citation statements)

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“…N -Methyltripyrrane 12b (100 mg, 0.214 mmol) was dissolved in TFA (2 mL) and stirred under nitrogen for 2 min. The solution was diluted with dichloromethane (400 mL), followed by the immediate addition of 1,3,5-cycloheptatriene-1,6-dicarbaldehyde (31.7 mg, 0.214 mmol), and left to stir for 16 h under nitrogen. The solution was shaken with 0.1% aqueous ferric chloride solution (200 mL) for 5 min, the layers were separated, and the organic phase was washed sequentially with water, 5% sodium bicarbonate solution, and water.…”

Section: Experimental Sectionmentioning

confidence: 99%

Synthesis and Characterization of N-Methylporphyrins, Heteroporphyrins, Carbaporphyrins, and Related Systems

Latham

Lash

2020

J. Org. Chem.

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MacDonald-type "3 + 1" condensations of an N-methyltripyrrane with a series of dialdehydes afforded a matched set of N-methylporphyrins, Nmethylheteroporphyrins, N-methyloxybenziporphyrin, N-methyloxypyriporphyrin, N-methyltropiporphyrin, and a N-methylcarbaporphyrin aldehyde. meso-Unsubstituted heteroporphyrins have been little explored previously, and this strategy was also used to prepare N-unsubstituted 21-oxa-, 21-thia-, and 21-selenaporphyrins. In every case, the N-methylporphyrinoids exhibited weaker, bathochromically shifted UV−Vis absorptions compared to their core unsubstituted congeners. However, proton NMR spectroscopy demonstrated that these derivatives retained strong diamagnetic ring currents and the presence of the internal alkyl substituents had little effect on the global aromatic characteristics. Nevertheless, the UV−Vis spectra of N-methyl-oxybenzi-and N-methyl-oxypyriporphyrins were dramatically altered and gave greatly weakened absorptions. N-Methyl-oxybenzi-and N-methyltropiporphyrins reacted with palladium(II) acetate to give stable palladium(II) complexes, demonstrating that N-alkylation alters the metalation properties for these carbaporphyrinoids. The organometallic derivatives also retained strongly aromatic properties, and the proton NMR spectra showed the N-methyl resonances near −3 ppm. N-Methylcarbaporphyrin-2-carbaldehyde also gave a palladium(II) complex, but this gradually rearranged at higher temperatures to afford a C-methyl complex. The results demonstrate that core alkylation of porphyrinoids greatly alters the reactivity and spectroscopic properties for these systems.

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Section: Experimental Sectionmentioning

confidence: 99%

Synthesis and Characterization of N-Methylporphyrins, Heteroporphyrins, Carbaporphyrins, and Related Systems

Latham

Lash

2020

J. Org. Chem.

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“…1 Similarly, cycloheptatriene-1-carbaldehyde has been obtained in moderate yield by the Vilsmeier reaction.2 The sole reported example of further substitution is that of diacetylation, giving the 1,6disubstitution product . 3 Other reagents lead to formation of oxidation or rearrangement products; thus attempted nitration of the system, under conditions applied to the preparation of other nitroalkenes, resulted in formation of the tropylium ion by hydride abstraction.4.5…”

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confidence: 99%

Preparation and X-ray crystal structure analysis of 1,6-dinitrocycloheptatriene

Burnett¹,

Conole²,

O'Donovan³

et al. 1994

J. Chem. Soc., Chem. Commun.

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ChemInform Abstract: METHYLENE‐BRIDGED (4N + 2)ANNULENES BY AN ASSEMBLY PRINCIPLE

Abstract: Die Polyendialdehyde (IId), (IVc), (Vc) und (VIc) werden als potentielle Schlüsselverbindungen für die Synthese überbrückter [4n + 2]Annulene betrachtet.

Cited by 2 publications

References 1 publication

Synthesis and Characterization of N-Methylporphyrins, Heteroporphyrins, Carbaporphyrins, and Related Systems

Synthesis and Characterization of N-Methylporphyrins, Heteroporphyrins, Carbaporphyrins, and Related Systems

Preparation and X-ray crystal structure analysis of 1,6-dinitrocycloheptatriene

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