Supramolecular dimeric structures of pyrazole-containing <i>meso</i>-oxo carbaphlorin analogues

Ishida, Masatoshi; Fujimoto, Hiroyuki; Morimoto, Tatsuki; Mori, Shigeki; Toganoh, Motoki; Shimizu, Soji; Furuta, Hiroyuki

doi:10.1080/10610278.2016.1158408

Cited by 10 publications

(15 citation statements)

References 53 publications

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“…In a recent paper, a TFA-promoted condensation of N -benzylpyrazole dialdehyde 212d with tripyrrane 36a in methanol–dichloromethane was reported . Following neutralization with triethylamine and oxidation with DDQ, oxophlorin analogue 215d was isolated in 12% yield (Scheme ).…”

Section: Pyrazole-containing Porphyrinoidsmentioning

confidence: 87%

“…Single-crystal XRD analysis showed that the porphyrinoid is planar and also demonstrated that a “head-to-head” dimer structure was present. Evidence for the formation of the dimer in solution was also presented Scheme ).…”

Section: Pyrazole-containing Porphyrinoidsmentioning

confidence: 99%

“…182 In a recent paper, a TFA-promoted condensation of Nbenzylpyrazole dialdehyde 212d with tripyrrane 36a in methanol−dichloromethane was reported. 186 Following neutralization with triethylamine and oxidation with DDQ, oxophlorin analogue 215d was isolated in 12% yield (Scheme 72). Cleavage of the benzyl moiety with AlCl 3 in benzene afforded the related N-unsubstituted oxophlorin 215e in 64% yield.…”

Section: Pyrazole-containing Porphyrinoidsmentioning

confidence: 99%

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Carbaporphyrinoid Systems

2016

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Following immediately after the serendipitous discovery of N-confused porphyrins, remarkably diverse carbaporphyrinoid systems have been synthesized and investigated. By replacing a pyrrolic unit within the porphyrin framework with cyclopentadiene, indene, azulene, cycloheptatriene, or benzene, new families of porphyrin-like macrocycles were produced. True carbaporphyrins are fully aromatic structures, while benziporphyrins are essentially devoid of macrocyclic aromatic character, and azuliporphyrins fall midway between the two extremes. Monocarbaporphyrinoids are superior organometallic ligands and form stable complexes with copper(III), silver(III), gold(III), nickel(II), palladium(II), platinum(II), rhodium(III), iridium(III), and ruthenium(II). Unusual oxidation reactions have also been discovered, commonly leading to derivatization of the internal carbon atom. In addition, structural rearrangements have been uncovered that allow the conversion of azuliporphyrins into benzocarbaporphyrins, and benziporphyrins into carbaporphyrins. Although less well studied, many examples of dicarbaporphyrinoids have been reported, and these show equally intriguing characteristics. Furthermore, contracted and expanded carbaporphyrinoids have been investigated. Studies in this area provide fundamental insights into the aromatic properties, tautomerization, and reactivity of porphyrins and related macrocyclic systems.

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Section: Pyrazole-containing Porphyrinoidsmentioning

confidence: 87%

Section: Pyrazole-containing Porphyrinoidsmentioning

confidence: 99%

Section: Pyrazole-containing Porphyrinoidsmentioning

confidence: 99%

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Carbaporphyrinoid Systems

2016

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“…Such approaches provide easy access to effectively obtain 1,3,5-trisubstituted pyrazoles with definite types of substituents. That approach is specifically topical due to the yearly increasing significance of the pyrazole sequence chemical variety for pharmaceutics, coordination chemistry, supramolecular chemistry, liquid crystals, polymers, and agricultural chemistry . Therefore, there has been much progress on development of common synthesis methods and for the functionalization of polysubstituted pyrazoles …”

Section: Introductionmentioning

confidence: 99%

Reactivity of Cross-Conjugated Enynones in Cyclocondensations with Hydrazines: Synthesis of Pyrazoles and Pyrazolines

et al. 2021

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The cyclocondensation of cross-conjugated enynones, dienynones, and trienynones (easily available due to low-cost starting compounds) with arylhydrazines leads to the regioselective synthesis of pyrazole derivatives (dihetaryl-substituted ethens, buta-1,3-diens, and hexa-1,3,5-triens) or results in 4,5-dihydro-1H-pyrazoles in good yield. The reaction path is controlled by the character of the substituent in enynone: the pyrazoles are obtained from the reaction of substrates that contain five-membered heteroaromatic substituents with arylhydrazines, and the 4,5-dihydro-1H-pyrazoles are obtained from the reaction of 1,5-diphenylpent-1-en-4-yn-3-one with arylhydrazines consistently. Despite the presence of a substituent, cyclocondensation of 2-hydrazinylpyridine with all of examined cross-conjugated enynones leads to the formation of pyrazoles. The reaction does not require special conditions (temperature, catalyst, inert atmosphere). The cyclocondensation pathways are determined by the electronic effect of an electron-rich five-membered heteroaromatic ring in the substrate. The synthesis allows use of various substituents and functional groups in enynone and hydrazine. The present method features high yields and simplicity of the product purification. The obtained pyrazoles possess fluorescent properties with a quantum yield up to 31%.

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“…Pyrazoles are very important functional moieties having extensive applications in pharmaceuticals, 1 agriculture, 2 supramolecular chemistry, 3 polymers, 4 liquid crystals, 5 ligands in catalysis 6 and many others. Despite the intricacy in N–N bond formations, these are widely present in nature 7 such as in withasomnine, pyrazofurin, formycin A and B, nostocine A, fluviol A–E, and pyrazole-3(5)-carboxylic acid and show remarkable biological potential.…”

Section: Introductionmentioning

confidence: 99%