| Autor: |
Golovanov AA; Togliatti State University, 14 Belorusskaya Str., 445020 Togliatti, Russia., Odin IS; Togliatti State University, 14 Belorusskaya Str., 445020 Togliatti, Russia., Gusev DM; Togliatti State University, 14 Belorusskaya Str., 445020 Togliatti, Russia., Vologzhanina AV; A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Science, 28 Vavilova Str., 119991 Moscow, Russia., Sosnin IM; Togliatti State University, 14 Belorusskaya Str., 445020 Togliatti, Russia., Grabovskiy SA; Ufa Institute of Chemistry, UFRS of the Russian Academy of Science, 71 October Av., 450054 Ufa, Russia. |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of organic chemistry [J Org Chem] 2021 May 21; Vol. 86 (10), pp. 7229-7241. Date of Electronic Publication: 2021 May 06. |
| DOI: |
10.1021/acs.joc.1c00569 |
| Abstrakt: |
The cyclocondensation of cross-conjugated enynones, dienynones, and trienynones (easily available due to low-cost starting compounds) with arylhydrazines leads to the regioselective synthesis of pyrazole derivatives (dihetaryl-substituted ethens, buta-1,3-diens, and hexa-1,3,5-triens) or results in 4,5-dihydro-1 H -pyrazoles in good yield. The reaction path is controlled by the character of the substituent in enynone: the pyrazoles are obtained from the reaction of substrates that contain five-membered heteroaromatic substituents with arylhydrazines, and the 4,5-dihydro-1 H -pyrazoles are obtained from the reaction of 1,5-diphenylpent-1-en-4-yn-3-one with arylhydrazines consistently. Despite the presence of a substituent, cyclocondensation of 2-hydrazinylpyridine with all of examined cross-conjugated enynones leads to the formation of pyrazoles. The reaction does not require special conditions (temperature, catalyst, inert atmosphere). The cyclocondensation pathways are determined by the electronic effect of an electron-rich five-membered heteroaromatic ring in the substrate. The synthesis allows use of various substituents and functional groups in enynone and hydrazine. The present method features high yields and simplicity of the product purification. The obtained pyrazoles possess fluorescent properties with a quantum yield up to 31%. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
