Synthesis of novel porphyrin chromophores from nitroarenes: Further applications of the Barton-Zard pyrrole condensation

Lash, Timothy D.; Wijesinghe, Chaminda B.; Osuma, Augustine T.; Patel, Jyoti

doi:10.1016/s0040-4039(97)00287-6

Cited by 47 publications

(31 citation statements)

References 29 publications

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“…Fused benzothiadiazole units gave more unusual effects. The monoannealed porphyrin (28) afforded two broad relatively weak Soret bands at 380 and 436 nm, while the visible region was dominated by two Q bands at 528 and 566 nm [79,80]. In 1% TFA-chloroform, two sharper Soret bands were observed at 422 and 434 nm.…”

Section: Phenanthro[910-b]porphyrins and Other Annelated Systemsmentioning

confidence: 99%

Modification of the porphyrin chromophore by ring fusion: identifying trends due to annelation of the porphyrin nucleus

Lash

2001

J. Porphyrins Phthalocyanines

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122

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ABSTRACT:The effects exerted by fused aromatic rings on the UV-vis spectra of porphyrins are surveyed. Modified porphyrin chromophores with fused benzene, 1,2-naphthalene, 9,10-phenanthrene or phenanthroline rings are surprisingly little affected even when a maximum number of ring fusions are incorporated. Linearly annealed naphtho-or anthraporphyrins show large red shifts to the Q bands but the Soret absorptions are weakened and undergo only minor bathochromic shifts. Fluoranthoporphyrins give multiple bands in the Soret region, but the Q band region is virtually unaffected by this tetracyclic ring system. On the other hand, metal chelates of fluoranthoporphyrins show surprisingly strong bands near 600 nm. Benzothiadiazole rings split and weaken the Soret band, but the Q bands region is unexceptional. However, metal coordination again produces relatively intense bands near 600 nm. The most significant results were obtained for porphyrins with fused acenaphthylene rings. Monoacenaphthoporphyrins (41) have three Soret bands at 387, 431 and 454 nm, and the longest wavelength Q band is shifted to 658 nm. opp-Diacenaphthoporphyrin (43) further shifts these bands with two Soret absorbances at 443 and 470 nm, and an additional strong peak is observed at 692 nm. The metal complexes of these systems also show strong bands between 602 and 656 nm. Still larger effects are produced by tetraacenaphthoporphyrin (47), the dication for which in trifluoroacetic acid (TFA)-chloroform has a Soret absorption at 528 nm. Tetraaryltetraacenaphthoporphyrins (48) are even more red shifted, showing Soret bands between 556 and 570 nm for the free bases and 565 to 588 nm for the related dications. The lead(II) chelate for tetraphenylporphyrin (48a) shows an additional 'hyper' spectral shift that brings the Soret band to 604 nm, and this effect can also be achieved by introducing four meso-phenylethynyl substituents onto the tetraacenaphthoporphyrin nucleus (49). In addition, by combining these two factors for the lead(II) chelate of 49, a record-breaking value for the Soret band of 642 nm can be achieved. Spectral shifts due to ring annelation in porphyrin analogues are also discussed, including those for oxybenziporphyrins, oxypyriporphyrins, carbaporphyrins and sapphyrins.

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Section: Phenanthro[910-b]porphyrins and Other Annelated Systemsmentioning

confidence: 99%

Modification of the porphyrin chromophore by ring fusion: identifying trends due to annelation of the porphyrin nucleus

Lash

2001

J. Porphyrins Phthalocyanines

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122

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“…18 Using this approach, 1,5-dinitronaphthalene and 2,7-dinitronaphthalene afforded naphthopyrroles 4 and 5, respectively, in 44-45% yield, although 1,8dinitronaphthalene gave rise to extensive decomposition and no pyrrolic product could be isolated in this case. 18 1,3-Dinitronaphthalene afforded two isomeric nitronaphthopyrrole products together with a dipyrrolic tricycle 6, 18 and the latter product could be isolated in 25% yield when the reaction was carried out in the presence of excess isocyanoacetate. It is worth noting that 1,5-and 2,7-dinitronaphthalenes cannot react a second time without sacrificing the 6p aromaticity of the remaining benzene ring, a factor that effectively prevents further reaction from occurring, but this not a problem in the formation of 6.…”

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confidence: 94%

Synthesis of Novel Pyrrolic Compounds from Nitroarenes and Isocyanoacetates Using a Phosphazene Superbase

Lash

Thompson

Werner

et al. 2000

Synlett

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102

155

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“…At this stage alongside the traditional procedure for expansion of the porphyrin macroring (building up of an aromatic ring basing on a functionally substituted porphyrin) a new more productive method was introduced consisting in construction of a system of pyrrole and aromatic fragment conjugated at the b-position of the pyrrole ring with subsequent bringing of the system into a porphyrin condensation [46]. The last approach resulted in the synthesis of phenanthroporphyrins and phenanthrolinoporphyrins, and also of thiadiazoloporphyrins which were taken up as molecular probes, photosensitizers in the photodynamic therapy of cancer, geochemical standards in the analysis of sedimentary metalloporphyrins [6].…”

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confidence: 99%

New Iodo- and Nitro-substituted Pyrroles

et al. 2005

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Treating 2,5-dimethyl-4-ethoxycarbonyl-and 2,5-dimethyl-4-carboxypyrroles with iodine furnished 3iodo-2,5-dimethyl-4-ethoxycarbonyl-and 3,4-diiodo-2,5-dimethylpyrroles. It was established that 3-iodo-2,5dimethyl-4-ethoxycarbonylpyrrole reacted at heating with silver nitrite to afford 2,5-dimethyl-3-nitro-4ethoxycarbonylpyrrole, and the same reagent oxidized 3,4-diiodo-2,5-dimethylpyrrole to give 3,4-diiodo-2-methyl-5-formylpyrrole.

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Synthesis of novel porphyrin chromophores from nitroarenes: Further applications of the Barton-Zard pyrrole condensation

Cited by 47 publications

References 29 publications

Modification of the porphyrin chromophore by ring fusion: identifying trends due to annelation of the porphyrin nucleus

Modification of the porphyrin chromophore by ring fusion: identifying trends due to annelation of the porphyrin nucleus

Synthesis of Novel Pyrrolic Compounds from Nitroarenes and Isocyanoacetates Using a Phosphazene Superbase

New Iodo- and Nitro-substituted Pyrroles

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