Quantum chemical study of regioselectivity of reactions of substituted pyrido[1,2-a]benzimidazoles with electrophiles

• Published in: Russian chemical bulletin Vol. 65; no. 3; pp. 644 - 647
• Main Authors: Begunov, R. S., Sokolov, A. A., Belova, V. O., Solov’ev, M. E.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-03-2016; Springer Nature B.V
• Subjects: Chemical reactions; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Full Articles; Imidazole; Inorganic Chemistry; Organic Chemistry; Quantum chemistry; Regioselectivity; Substitutes; regioselectivity; DFT/B3LYP/631G; Ar reactions; benzimidazoles; pyrido[1,2; frontier molecular orbital theory
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-016-1349-4

The geometric, charge, and electronic characteristics of 7-substituted pyrido[1,2-
a
]benzimidazoles and their cations were calculated using the DFT method with the B3LYP functional in the 6-31G** basis set. High regioselectivity of the reactions between the condensed imidazole derivatives and electrophilic agents was explained by the results of quantum chemical simulation. It was concluded that the
S
E
Ar reaction was orbitally controlled. According to Fukuís concept, the reaction center of the electrophilic attack was the C(8) atom of the heterocyclic system, which agreed well with the experimental data.