Diastereoisomerism and electrochemical behaviour— an investigation of redox-active cyclophanes

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

“…The 13 C NMR spectrum of compound 4 at 333 К shows 20 signals at low field (the relative intensities of two signals correspond to two carbon atoms each) and four signals at δ 71-41.…”

“…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 the indolizine system having a favorable spatial arrangement.…”

“…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][11][12][13][14][15] Indolizines 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.…”

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

“…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.…”

3-Indolizin-2-ylquinoxalines and the derived monopodands

“…12 The synthesis of bis indolizines is also of considerable interest. These compounds are reversible two step redox systems, 13,14 which facilitate the occur rence of atropoisomerism 15 and serve as the starting compounds in the synthesis of heterocyclophanes and ligands 16, 17 possessing the desired properties. The intro duction of the indolizine fragment containing the free locally π excessive active reaction centers C(1) and C(3) into functionalized heterocyclic systems will extend the synthetic potential of these compounds.…”