Cyclization of β‐Chlorovinyl Thiohydrazones into Pyridazines: A Mechanistic Study

Cyclization of β‐Chlorovinyl Thiohydrazones into Pyridazines: A Mechanistic Study Full article

Journal

European Journal of Organic Chemistry
ISSN: 1434-193X , E-ISSN: 1099-0690

Output data

Year: 2019, Volume: 2019, Number: 2-3, Pages: 527-536 Pages count : 10 DOI: 10.1002/ejoc.201801118

Authors

Komendantova Anna S. ¹ , Fakhrutdinov Artem N. ¹ , Menchikov Leonid G. ¹ , Sukhorukov Alexey Yu. ¹ , Zavarzin Igor V. ¹ , Volkova Yulia A. ¹

Affiliations

1	N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russia.

Extensive experimental and theoretical investigations on the isomerization and heterocyclizations of β-chlorovinyl thiohydrazones derived from oxamic acid thiohydrazides and β-chlorovinyl aldehydes were performed to elucidate the reaction mechanism of pyridazine formation. We showed that model β-chlorovinyl thiohydrazone undergoes multiple isomerization reactions in solution induced by thione–thiol tautomerism and Z/E-isomerization at the C=N bond. Mechanistic rationalization along with computational studies demonstrated that pyridazine is predominantly generated from the Z-thiol isomers by 6π-electrocyclization of the thiohydrazone-derived 2,3-diazatriene intermediate. The autocatalytic character of cyclization accelerated by the formation of acid was demonstrated by means of 1H NMR monitoring.

Komendantova A.S. , Fakhrutdinov A.N. , Menchikov L.G. , Sukhorukov A.Y. , Zavarzin I.V. , Volkova Y.A.
Cyclization of β‐Chlorovinyl Thiohydrazones into Pyridazines: A Mechanistic Study
European Journal of Organic Chemistry. 2019. V.2019. N2-3. P.527-536. DOI: 10.1002/ejoc.201801118 WOS Scopus OpenAlex

Web of science:	WOS:000459821300035
Scopus:	2-s2.0-85055552926
OpenAlex:	W2890292020

DB	Citing
OpenAlex	8
Scopus	7
Web of science	7