Результаты исследований: Научные публикации в периодических изданиях › статья
Steric hindrances to the cycloaddition of (Z)-1-arylmethylidene-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides to N-arylmaleimides. / Koptelov, Y.B.; Antuganov, D.O.; Molchanov, A.P.; Kostikov, R.R.
в: Russian Journal of Organic Chemistry, № 7, 2015, стр. 972-981.Результаты исследований: Научные публикации в периодических изданиях › статья
}
TY - JOUR
T1 - Steric hindrances to the cycloaddition of (Z)-1-arylmethylidene-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides to N-arylmaleimides
AU - Koptelov, Y.B.
AU - Antuganov, D.O.
AU - Molchanov, A.P.
AU - Kostikov, R.R.
PY - 2015
Y1 - 2015
N2 - © 2015 Pleiades Publishing, Ltd.Sterically hindered cycloaddition of (Z)-1-arylmethylidene-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides to 4-mono- and 2,6-disubstituted N-arylmaleimides requires prolonged heating (40-60 h) at ~150-155°C and yields mixtures of diastereoisomeric cycloadducts. The observed diastereoselectivity is determined by both electronic and steric interactions, depending on the nature and position of substituents in the azomethine imine and maleimide. The reactions of (Z)-1-(2,6-dichlorobenzylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ide with 4-substituted N-arylmaleimides give mainly the corresponding cis adducts as a result of preferential exo attack by the dipolarophile, whereas trans adducts predominate in the cycloaddition of (Z)-1-(4-X-benzylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ide and (Z)-1-(2,6-dichlorobenzylidene)-5,5-dimethyl-3-oxopyrazolidin- 1-ium-2-ide to 2,6-disubstituted N-arylmaleimides.
AB - © 2015 Pleiades Publishing, Ltd.Sterically hindered cycloaddition of (Z)-1-arylmethylidene-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ides to 4-mono- and 2,6-disubstituted N-arylmaleimides requires prolonged heating (40-60 h) at ~150-155°C and yields mixtures of diastereoisomeric cycloadducts. The observed diastereoselectivity is determined by both electronic and steric interactions, depending on the nature and position of substituents in the azomethine imine and maleimide. The reactions of (Z)-1-(2,6-dichlorobenzylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ide with 4-substituted N-arylmaleimides give mainly the corresponding cis adducts as a result of preferential exo attack by the dipolarophile, whereas trans adducts predominate in the cycloaddition of (Z)-1-(4-X-benzylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ide and (Z)-1-(2,6-dichlorobenzylidene)-5,5-dimethyl-3-oxopyrazolidin- 1-ium-2-ide to 2,6-disubstituted N-arylmaleimides.
U2 - 10.1134/S1070428015070143
DO - 10.1134/S1070428015070143
M3 - Article
SP - 972
EP - 981
JO - Russian Journal of Organic Chemistry
JF - Russian Journal of Organic Chemistry
SN - 1070-4280
IS - 7
ER -
ID: 4004827