Electronic effects of heteroaromatic groups

This article is designed to fill this gap by systematizing the available data on the electronic effects of heteroaromatic groups as substituents. References are made only to the publications that contain quantitative characteristics of these effects both for the parent heteroaromatic groups and for those containing substituents in the heterocycle. Evidence is cited on traditional heteroaromatic substituents and, exceptionally, on some substitutents that are partly hydrogenated or that contain prototropic tautomeric fragments that may formally be considered aromatic. 

Within the limits of the topic under discussion, the electronic effects of heteroaromatic groups can be described quantitatively by a set of various a constants. The most fundamental of these are the inductive constant a, and the... 

A. Approaches and Methods for Evaluating Electronic Effects of Heteroaromatic Groups... 

Attempts have also been made to calculate theoretically the constants for the pyridyl and protonated pyridyl groups (75BAP923). But these a constants cannot serve as quantitative characteristics of the electronic effects of heteroaromatic groups due to the strong dependence on the particular quantum chemical parameters (coulomb and resonance integrals) used in the calculations. 

Despite the fact that a number of problems remain unsolved, the data reported in this article are expected to direct chemists interested in heterocycles to the large variety of work on the electronic effects of heteroaromatic groups. 

Mamaev, V. P., Shkurko, O. P., Baram, S. G., Electron Effects of Heteroaromatic and Substituted Heteroaromatic Groups,... 

Electronic effects of heteroaromatic and substituted heteroaromatic groups,... 

The present volume consists of five chapters. The first, by V. P. Mamaev and his colleagues, O. P. Shkurko and S. G. Baram, gives an account of the electronic effects of heteroaromatic and substituted heteroaromatic groups. It was with great sorrow that we learned of Professor Mamaev s untimely death late last year. This chapter, which will be a great utility to heterocyclic chemists, is thus his last major publication. We will remember him for it. 

S. G., Electron Effects of Heteroaromatic and Substituted Heteroaromatic Groups, 42, 1. 

The authors suggest that the inductive constants for the heteroaromatic substituents, previously determined for carbon compounds, might not adequately reflect the electronic effects of these groups in the germanium compounds. 

C. Electronic Effects of Five-Membered Heteroaromatic Groups. 21... 

Evidence on the electronic effects of substituted heteroaromatic groups is, in our opinion, of greatest interest for researchers engaged in the field of synthetic organic chemistry, pharmaceutical and applied chemistry, and molecular spectroscopy. This evidence is therefore discussed separately (Section III). Another separate section (I V,B) deals with the peculiarities of the effect of substituents in the heteroaromatic ring and with the approaches to the a priori evaluation of inductive and resonance effects of such composite substituents. 

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