Synthesis and Isomerization of Imino-Fused N-Confused Porphyrin

Kashiwagi, Norimasa; Akeda, Takeshi; Morimoto, Tatsuki; Ishizuka, Tomoya; Furuta, Hiroyuki

doi:10.1021/ol0703534

Cited by 29 publications

(21 citation statements)

References 18 publications

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“…In certain cases, much milder nitrating agents, such as copper(II) nitrate, are sufficient to introduce the nitro group on the periphery of metalloporphyrins. For the effective NO 2 introduction to the other porphyrinoids, for example, corrole or N‐confused porphyrin, solely metal nitrites or nitric acid have been employed to date …”

Section: Introductionmentioning

confidence: 99%

Nitration of Norcorrolatonickel(II): First Observation of a Diatropic Current in a System Comprising a Norcorrole Ring

Deng

Stępień

et al. 2016

Chemistry A European J

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A one-pot reaction of 5,14-bis(mesityl)-norcorrolatonickel(II) with isoamyl nitrite under mild reaction conditions resulted in the consecutive formation of 3-nitro-, 3,12-dinitro- and 3,16-dinitro-, 3,7,12-trinitro-, and 3,7,12,16-tetranitro-norcorrolatonickel(II) in 50-80% yield. The substituted macrocycles retained their antiaromatic character. The observed regioselectivity of the substitution was analyzed by comparing the relative energies of the DFT energy-optimized models of the radical or arenium cationic intermediates that can be formed upon reaction with NO2. The nitrated systems were characterized by high-resolution mass spectrometry, NMR and UV/Vis spectroscopy, X-ray diffraction analysis, cyclic voltammetry, and DFT calculations. A significant and systematic cathodic shift of the redox couples was observed to correlate with an increasing number of the NO2 group. A decrease of the LUMO energies in the tri- and tetra-nitrated products stabilizes mono- and bis-reduced complexes of these ligands. The reduction takes place on the macrocycle rather than on the metal ion leading to the consecutive formation of stable paramagnetic monoanion radicals and water-soluble diamagnetic dianions with an aromatic character, which were revealed by ESR and (1)H NMR measurements, respectively. The electronic structures of the reduced forms were analyzed by extensive TD-DFT calculations.

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Section: Introductionmentioning

confidence: 99%

Nitration of Norcorrolatonickel(II): First Observation of a Diatropic Current in a System Comprising a Norcorrole Ring

Deng

Stępień

et al. 2016

Chemistry A European J

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“…Substitution reactions in the core of N-confused porphyrin 1.111;112 N-confused porphyrin 1 is transformed into the 21-nitrosubstituted derivative 72-NO 2 in the course of the reaction between 1 and sodium nitrite under acidic conditions (Scheme 27) 112. The C(21)-nitro substituent was easily reduced to an amino group with the use of tin(II) chloride 113. The unique modifications of the N-confused porphyrin core are available after coordination.Thus, the reaction of nickel(II) N-confused porphyrin 52 with DDQ in the presence of sodium methoxide resulted in nickel(II) 21-cyano-N-confused porphyrin 74 (Scheme 28).…”

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confidence: 99%

Core chemistry and skeletal rearrangements of porphyrinoids and metalloporphyrinoids

2015

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Core alteration, affording heteroporphyrinoids and carbaporphyrinoids, allows for the exploration of porphyrin-like or porphyrin-unlike coordination chemistry. Such a strategy has provided a fundamental change in the approach to macrocyclic organometallic chemistry. The specific reactivity of porphyrinoids has offered an insight into reactions inside particularly shaped macrocyclic architecture, including metal-mediated organic transformations. This review focuses on alterations of macrocycles, made of four carbocyclic/heterocyclic subunits, which resemble the structure of porphyrin or porphyrin isomers, providing, however, remarkable porphyrin-like (XNNN), (CNNN), (CNCN) or (C2NNN) surroundings. To facilitate the understanding of the discussed subject matter, all addressed reactions reflecting core reactivity have been formally grouped into nine categories distinguished by the principal type of transformation addressed: (1) alkylation or arylation, (2) core heteroatom replacement, (3) oxidation and oxygenation, (4) substitution, (5) macrocyclic fusion, (6) core bridging, (7) ring contraction, (8) ring expansion, and (9) C-H and C-C bond activation. The distinctive macrocyclic environment creates a long-sought opportunity to trap unique organometallic transformations which include instances of benzene ring contraction to cyclopentadiene or the formation of an unprecedented metalloporphyrinoid: 21-pallada-23-telluraporphyrin. This review offers certain challenging perspectives which target the goals of organometallic bond activation.

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“…Note that the electric charges on the N (22) and N(24) atoms of 8 and 13 are almost identical, both in Mulliken and natural population analyses. Unlike in the case of the imino-fused N-confused porphyrin having a similar [5.7.5]-tricyclic ring structure in the macrocyclic core, [19] thermal isomerization from 9 aa to 9 ab was not observed. When 9 aa was heated at 180 8C in 1,2-Cl 2 C 6 H 4 under Ar, no sign of formation of 9 ab was observed by 1 H NMR analysis.…”

Section: Resultsmentioning

confidence: 67%

Endocyclic Extension of Porphyrin π‐System by Interior Functionalization of N‐Confused Porphyrins

Toganoh

Kimura

Furuta

2008

Chemistry A European J

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Internally alkynylated or cyanated N-confused porphyrins have been prepared, and these have been characterized by NMR, UV/Vis/NIR absorption, and X-ray analysis. The desired porphyrins have been synthesized by interconversion between an N-confused porphyrin and an N-fused porphyrin. In the case of terminal alkyne derivatives, intramolecular addition of a pyrrolic NH moiety to the triple bond occurred at ambient temperature to give etheno-bridged N-confused porphyrins. Significant bathochromic shifts in the absorbances of these compounds may be reasonably explained in terms of an increase in their HOMO energy levels due to effective overlap of the porphyrin pi-orbital and the bridged alkene pi-orbital. The corresponding rhodium(I) complexes have also been prepared, and these have been characterized by NMR and X-ray analysis.

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Synthesis and Isomerization of Imino-Fused N-Confused Porphyrin

Cited by 29 publications

References 18 publications

Nitration of Norcorrolatonickel(II): First Observation of a Diatropic Current in a System Comprising a Norcorrole Ring

Nitration of Norcorrolatonickel(II): First Observation of a Diatropic Current in a System Comprising a Norcorrole Ring

Core chemistry and skeletal rearrangements of porphyrinoids and metalloporphyrinoids

Endocyclic Extension of Porphyrin π‐System by Interior Functionalization of N‐Confused Porphyrins

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