QUANTUM-CHEMICAL INVESTIGATION OF THE ELECTROPHILE AFFINITY OF MOLECULES OF FIVE-MEMBERED HETEROCYCLES WITH ONE HETEROATOM AND SOME MODEL SYSTEMS
DOI:
https://doi.org/10.1007/7276Keywords:
simple derivatives of N, O, S, and Se, five-membered heteroaromatic compounds with one heteroatom, quantum-chemical calculations, HF, B3LYP, and MP2 methods, modeling electrophilic aromatic substitution reactions, relative stability of onium states, affinity to proton and other electrophilesAbstract
Quantum-chemical calculations have been made of the energy characteristics of the molecules of pyrrole, furan, thiophene, and selenophene, the simplest derivatives of N, O, S, and Se with sp3- and sp2-hybridized C atoms and heteroatoms, and also of the products of addition of proton and certain other electrophiles to these molecules . The calculations were carried out by HF, B3LYP, and MP2 methods with the 6-31+G(d) basis set with corrections to the energy of zero-point vibrations. It was shown that the values of the affinity of the nitrogen-containing systems towards the electrophile were significantly greater than for their analogs, derivatives of chalcogens, while the relative stability of the onium states of the latter depends both on the hybridization of the heteroatoms, and also on the nature of the electrophile. Analysis of the obtained results made it possible to build a stability series of the onium compounds and to interpret the special features of the positional selectivity in electrophilic substitution reactions of five-membered heteroaromatic compounds with one heteroatom.How to Cite
Belen'kii, L. I.; Nesterov, I. D.; Chuvylkin, N. D. Chem. Heterocycl. Compd. 2008, 44, 1339. [Khim. Geterotsikl. Soedin. 2008, 1645.]
For this article in the English edition see DOI 10.1007/s10593-009-0197-7
