Electrochemical studies of methyl-3-benzoyl indolizine carboxylates
Indolizine derivatives have been used in medicine and pharmacology due to their biological activity and therapeutical effects. Their capacity to form surface films and to be used as sensors in modern technologies makes them interesting to be studied. This work is devoted to the study of methyl-3-benzoyl indolizine carboxylates by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It is pursued the influence of concentration on CV and DPV curves and that of the scanning domain and rate on the CV curves. The CV and DPV results are in good agreement. There are established the number and characteristics of the redox processes for each compound. The common features and differences between their electrochemical behaviour were analyzed.
Electrochemical studies of biologically active indolizines
Abstract The electrochemical behavior of indolizine ethers, esters, tosylates, sulfonates and other indolizine and azaindolizine derivatives has been investigated by cyclic voltammetry and preparative electrolysis. The cyclic voltammetric data show that the E ° values, taken as the midpoints between the anodic and cathodic peak potentials, are sensitive to the identities of the substituents at C-1, C-2 and C-7 positions. The E ° values have been correlated with the Hammett substituent parameters. As expected, low E ° values are seen for electron donating substituents and higher E ° values are seen for electron withdrawing substituents. The cyclic voltammograms of indolizine derivatives with an oxygen atom connected to the C-1 position exhibit a one-electron reversible oxidation and a further, less well-defined, one-electron irreversible oxidation at higher E ° values. The cyclic voltammograms of indolizines with hydrogen atom or thienyl substituents connected to the C-1 position exhibit only a one-electron irreversible oxidation. Electrochemical bulk oxidations of indolizines with an oxygen atom at the C-1 position afforded oxoindolizinium salts in decent yields, whereas indolizines with a hydrogen atom at C-1 afforded 1,1′ dimers of indolizines as products in good yields. Bulk oxidation of 1-(α-hydroxybenzyl)-2,3-diphenylindolizine-7-carbonitrile afforded an unexpected ketone product in which the carbonyl group of the indolizine is connected at C-8 instead of at the C-1 position of the starting material. The findings described herein support our hypothesis that certain indolizine derivatives may inhibit lipid peroxidation by an electron transfer mechanism.
Mehrstufige reversible Redoxsysteme. LXI. Synthese von 1,4‐Bis(2‐methyl‐indolizin‐1‐yl‐methyl)‐benzol und verwandter Modellverbindungen
Multi-Step Redox Systems. LXI. Synthesis of 1,4-Bis(2-methyl-indolizin-1-yl-methyl)-benzene and Related Model Compounds 
 
 
 
The synthesis of 1a, in which two 1-indolizine units are connected by a p-xylylene bridge is preformed from its 3,3′bis-acetyl derivative 1b via the precursors 8–11. This route was first tested by the synthesis of benzyl indolizines 2b and 2a via the pyridyl-aminopropanol 3a. 2a can be oxidatively dimerized to the 3,3′-bis-indolizine 6 which forms a perfectly reversible two step redox system with KSEM = 4.7 × 105.