Switchable electron-rich biindolizine-based macrocycles: synthesis and redox properties

Kreher, Thomas; Sonnenschein, Helmut; Costisella, Burkhard; Schneider, María Gabriela Montiel

doi:10.1039/a702433i

Cited by 24 publications

(6 citation statements)

References 11 publications

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“…The low yield is also observed in the oxidation of hetarylindolizines. 9 The use of molecular iodine in the oxidation of compound 6a to cyclophane 7 was successful (see Ref. 1).…”

Section: Synthesis Of Heterocyclophanes and Their Acyclic Precursorsmentioning

confidence: 98%

Macrocycles, derivatives of nitrogen-containing heterocycles 2. Synthesis and electrochemical properties of diindolizinadiquinoxalinacyclooxaalkaphanes

et al. 2009

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Phenylindolizinylquinoxalinomonopodands, obtained by the reaction of 1 (phenylindolizin 2 yl)quinoxalin 2(1H) one with corresponding dibromotrioxa and dibromopentaoxaalkanes, undergo oxidative dehydrocyclization assisted by molecular iodine to yield new redox active diindolizinadiquinoxalinacyclooxaalkaphanes. Using CVA, the indolizine fragments of the heterocyclophanes in acetonitrile are found to undergo three step oxidation with transfer of one electron in each step. The first and the third steps are reversible, whereas the second is irreversible. The oxidation at potentials of the first peak leads to the stable radical cations registered by ESR (g = 2.0024, a 2N = 0.26 mT).

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“…The low yield is also observed in the oxidation of hetarylindolizines. 9 The use of molecular iodine in the oxidation of compound 6a to cyclophane 7 was successful (see Ref. 1).…”

Section: Synthesis Of Heterocyclophanes and Their Acyclic Precursorsmentioning

confidence: 98%

Macrocycles, derivatives of nitrogen-containing heterocycles 2. Synthesis and electrochemical properties of diindolizinadiquinoxalinacyclooxaalkaphanes

et al. 2009

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“…Thus, H(5´) in the ring of compound 8 is also more shielded (by 0.42 ppm) compared to the analogous proton in open structure 7. 16 Therefore, based on the results of 2D NMR spectro scopy, mass spectrometric data, and the data published in the literature for model compounds, we established the structure of macrocyclic compound 4.…”

Section: Structural Characteristics Of Cyclopentadecaphanementioning

confidence: 99%

“…15, 16 However, according to the terminal group concept, 17,18 the addition of heteroaromatic systems, which bear dif ferent types of atoms, at the ends of the oligo(ethylene glycol) chain substantially facilitates the complex forma tion. In addition, due to a combination of the π systems of heteroaromatic rings with electron rich indolizine frag ments, the ability of such compounds to serve as active hosts with respect to guests containing electron deficient aromatic moieties is substantially higher.…”

mentioning

confidence: 99%

Synthesis, structure, and electrochemical properties of 12,42-dioxo-21,31-diphenyl-7,10,13-trioxa-1,4(3,1)-diquinoxalina-2(2,3),3(3,2)-diindolizinacyclopentadecaphane

et al. 2007

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The oxidative dehydrocyclization of the 3 (indolizin 2´ yl) 2 oxoquinoxaline monopodand performed either electrochemically or under the action of molecular iodine affords new redox active heterocyclophane consisting of the redox switchable biindolizine fragment combined with the polyether bridged π deficient quinoxaline systems. The single crystal X ray diffrac tion study showed that the trioxaundecane chain of heterocyclophane adopts an extended conformation, and one of the phenyl substituents of the molecule closes the pseudocavity formed by the spacer from one of the sides. The cyclic voltammetric study of heterocyclophane in MeCN and DMF showed the three step oxidation of the indolizine fragments accompanied by the single electron transfer in each step. The first and third steps are reversible, and the second step is irreversible. The oxidation at potentials of the first peak gives rise to stable radical cations detected by the ESR method (g = 2.0024, a 2N = 0.26 mT).In recent years, the synthesis of macrocyclic com pounds, which can reversibly respond to external actions (thermal, photochemical, electrochemical, pH, etc.) by changing important properties and characteristics (the cavity size, the surface shape, the electronic structure, the complexing ability, etc.) due to the specially introduced functional groups or fragments, has taken a special place in supramolecular chemistry. 1 Such "sensitive" hetero cyclophanes containing redox active biindolizine systems can serve as molecular switches 2 and membrane carriers 3 and are of great interest in the design of new sensors for modern technologies based on molecular processes. Un like redox active compounds (ferrocenes, 4,5 tetrathia fulvalenes, 6,7 and quaternized 4,4´ bipyridines 8,9 ), bi indolizines have found little use as active regions, which make cyclophanes able to respond to external actions, in spite of the fact that biindolizines are quite stable two step redox systems, whose electrochemical behavior has been studied in sufficient detail. 10-15Indolizines are π rich compounds, which are readily oxidized (~0.2-0.3 V relative to Fc 0/+ ) to form radical cations. 10-14 The stability and subsequent transforma tions of radical cations are determined primarily by the presence of hydrogen atoms in the pyrrole ring of the indolizine system. The radical cations and dications of 3,3´ biindolizines, in which all hydrogen atoms in the five membered ring are replaced by alkyl or aryl groups, are quite stable and can be isolated and characterized as perchlorates. 12 The electrochemical behavior of two dia stereomers of macrocyclic biindolizines, in which both heterofragments are linked at positions 3,3´ and, through a bridge, at positions 1,1´, is different. 13 Thus, the diaste reomer having the anti configuration is oxidized to form stable radical cations and dications, whereas the oxida tion of the diastereomer having the syn configuration is followed by the intramolecular cyclization with the in volvement of the C(5) and C(5´) atoms of the pyridine rings of...

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“…Среди индолизиновых макроциклов, кроме син-тезированных в наших работах, [13][14][15][16] известны ма-кроциклы с одним индолизиновым [17,18] и двумя [19][20][21][22] индолизиновыми (бииндолизиновым) фрагментами. Последние, благодаря редокс-активному фрагменту, относятся к макроциклическим соединениям, способ-ным обратимо реагировать на внешние воздействия.…”

Section: Introductionunclassified

Synthesis, Electrochemical and Mass Spectrometric Properties of the Macrocycles with One, Two and Four 3,3´-Biindolizine Redox-Active Fragments on the 3-(Indolizin-2-yl)quinoxalin-2-one Platform

Калинин¹,

Rakov²,

Latypova³

et al. 2016

MHC

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Switchable electron-rich biindolizine-based macrocycles: synthesis and redox properties

Cited by 24 publications

References 11 publications

Macrocycles, derivatives of nitrogen-containing heterocycles 2. Synthesis and electrochemical properties of diindolizinadiquinoxalinacyclooxaalkaphanes

Macrocycles, derivatives of nitrogen-containing heterocycles 2. Synthesis and electrochemical properties of diindolizinadiquinoxalinacyclooxaalkaphanes

Synthesis, structure, and electrochemical properties of 12,42-dioxo-21,31-diphenyl-7,10,13-trioxa-1,4(3,1)-diquinoxalina-2(2,3),3(3,2)-diindolizinacyclopentadecaphane

Synthesis, Electrochemical and Mass Spectrometric Properties of the Macrocycles with One, Two and Four 3,3´-Biindolizine Redox-Active Fragments on the 3-(Indolizin-2-yl)quinoxalin-2-one Platform

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