Combined experimental and theoretical studies of regio- and stereoselectivity in reactions of beta-isoxazolyl- and beta-imidazolyl enamines with nitrile oxides / Efimov Ilya V.,Shafikov Marsel Z.,Beliaev Nikolai A.,Volkova Natalia N.,Beryozkina Tetyana V.,Dehaen Wim,Fan Zhijin,Grishko Viktoria V.,Lubec Gert,Slepukhin Pavel A.,Bakulev Vasiliy A. // BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY. - 2016. - V. 12, l. . - P. 2390-2401.

ISSN/EISSN:

1860-5397 / нет данных

Type:

Article

Abstract:

Reactions of beta-azolyl enamines and nitrile oxides were studied by both experimental and theoretical methods. (E)-beta-(4-Nitroimidazol-5-yl), (5-nitroimidazol-4-yl) and isoxazol-5-yl enamines smoothly react regioselectively at room temperature in dioxane solution with aryl, pyridyl, and cyclohexylhydroxamoyl chlorides without a catalyst or a base to form 4-azolylisoxazoles as the only products in good yields. The intermediate 4,5-dihydroisoxazolines were isolated as trans isomers during the reaction of (E)-beta-imidazol-4-yl enamines with aryl and cyclohexylhydroxamoyl chlorides. Stepwise and concerted pathways for the reaction of beta-azolyl enamines with hydroxamoyl chlorides were considered and studied at the B3LYP/Def2-TZVP level of theory combined with D3BJ dispersion correction. The reactions of benzonitrile oxide with both E-and Z-imidazolyl enamines have been shown to proceed stereoselectively to form trans-and cis-isoxazolines, respectively. The preference of E-isomers over Z-isomers, driven by the higher stability of the former, apparently controls the stereoselectivity of the investigated cycloaddition reaction with benzonitril. oxide. Based on the reactivity of azolyl enamines towards hydroxamoyl chlorides, a novel, effective catalyst-free method was elaborated to prepare 4-azolyl-5-substituted isoxazoles that are otherwise difficult to obtain.

Author keywords:

beta-azolyl enamine; {[}3+2]-cycloaddition; isoxazole; isoxazoline; nitrile oxide 1,3-DIPOLAR CYCLOADDITION; SELF-CONDENSATION; ALLYL COMPOUNDS; BASIS-SETS; DERIVATIVES; REACTIVITY; SELECTIVITY; INHIBITORS; DESIGN; RN

DOI:

10.3762/bjoc.12.233

Web of Science ID:

ISI:000388131000001

Соавторы в МНС:

Другие поля

Поле	Значение
Month	NOV 15
Publisher	BEILSTEIN-INSTITUT
Address	TRAKEHNER STRASSE 7-9, FRANKFURT AM MAIN, 60487, GERMANY
Language	English
Keywords-Plus	1,3-DIPOLAR CYCLOADDITION; SELF-CONDENSATION; ALLYL COMPOUNDS; BASIS-SETS; DERIVATIVES; REACTIVITY; SELECTIVITY; INHIBITORS; DESIGN; RN
Research-Areas	Chemistry
Web-of-Science-Categories	Chemistry, Organic
Author-Email	fanj@nankai.edu.cn v.a.bakulev@urfu.ru
ResearcherID-Numbers	Efimov, Ilya/H-8741-2016
ORCID-Numbers	Efimov, Ilya/0000-0003-1123-987X Shafikov, Marsel/0000-0003-0495-0364
Funding-Acknowledgement	Russian Scientific Foundation {[}15-13-10031]
Funding-Text	M. Z. Shafikov is grateful to Prof. Duncan Bruce (York) for the hospitality and a chance to work in his research group. This work was supported by the Russian Scientific Foundation (15-13-10031).
Number-of-Cited-References	54
Usage-Count-Last-180-days	5
Usage-Count-Since-2013	20
Journal-ISO	Beilstein J. Org. Chem.
Doc-Delivery-Number	EC4UZ