Hetarenes with a bridge nitrogen atom. 6. Ambident properties of the oxazolo[3,2-a]pyridinium nucleus in reactions with nucleophiles: Prediction and experiment

Autor:	K. Yu. Pasichnichenko, Eugene V. Babaev, D. A. Maiboroda
Rok vydání:	1997
Předmět:	chemistry.chemical_compound chemistry Nucleophile Organic Chemistry Pyridine Piperidine Pyridinium Ring (chemistry) Photochemistry Medicinal chemistry Oxazole Adduct Ion
Zdroj:	Chemistry of Heterocyclic Compounds. 33:338-342
ISSN:	1573-8353 0009-3122
DOI:	10.1007/bf02253115
Popis:	We have studied the problem of ambident opening of five-membered and six-membered rings of the heteroaromatic oxazolo[3,2-a]pyridinium cation. A quantum chemical SINDO1 calculation of the energies of isomeric adducts of this cation with nucleophiles predicts preferential formation of the C9-adduct in the case of OH and SH ions with opening of the oxazole fragment, while for nitrogen-containing nucleophiles (NH2, NMe2) attack at the C(5) atom is also likely with opening of the pyridine fragment. We have experimentally observed that this cation undergoes opening of the five-membered ring in reaction with NaSH, opening of the six-membered ring in reaction with piperidine, and opening of both rings in reaction with ammonia.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::fb48ee7c1077c8ba0b596422bf5c9ca3 https://doi.org/10.1007/bf02253115 Zobrazit plný text záznamu Full text from SpringerLink