NMR Spectra of indolizines and their σ complexes

Abstract

New and previous data on the¹H and ¹³C NMR spectra of indolizines with electron-withdrawing groups at C(¹), C(³), C(⁶), and C(⁸) obtained in our laboratory are reviewed. The chemical shifts in the ¹³C NMR spectra were compared with the total atomic charge values calculated by the MNDO method. Feasibility was demonstrated for the use of PMR spectroscopy to identify isomers for pairs of 1(3)- and 6(8)-substituted indolizines and to establish the protonation site of such compounds. Evidence was obtained for the unexpected ipso protonation in 3-substituted indolizines. The spectral properties of cationic and anionic sigma complexes involving indolizines were discussed.

How to Cite
Babaev, E. V.; Torocheshnikov, V. N.; Bobrovskii, S. I. Chem. Heterocycl. Compd. 1995, 31, 1079. [Khim. Geterotsikl. Soedin. 1995, 1235.]

For this article in the English edition, see DOI https://doi.org/10.1007/BF01165054