2-Amino, 4-amino- and 2-nitrostilbenes react with mesitonitrile oxide affording the 5-substituted phenyldihydro-isoxazole as the more abundant regioisomer, while 3-amino and 3-, 4-nitro derivatives give comparable amounts of the two regioisomers. Reactions of 2-acylamino derivatives show a lower regioselectivity and furthermore no solvent effect was found for the regiochemistry of 2-aminostilbene and its N-acetyl derivative. These experimental results indicate that reactions of 2-aminostilbene and its N-acyl derivatives are not governed by hydrogen bonding or steric effects. They are not explainable by the frontier molecular orbital theory, but semiempirical PM3 calculations performed on regioisomeric transition structures gave values of regioisomeric ratios well in accord with those experimentally observed.

Cycloadditions of Mesitonitrile Oxide with Amino- and Nitrostilbenes

CORSARO, Antonino;CHIACCHIO, Ugo;PISTARA', Venerando;RESCIFINA, Antonio;
2000-01-01

Abstract

2-Amino, 4-amino- and 2-nitrostilbenes react with mesitonitrile oxide affording the 5-substituted phenyldihydro-isoxazole as the more abundant regioisomer, while 3-amino and 3-, 4-nitro derivatives give comparable amounts of the two regioisomers. Reactions of 2-acylamino derivatives show a lower regioselectivity and furthermore no solvent effect was found for the regiochemistry of 2-aminostilbene and its N-acetyl derivative. These experimental results indicate that reactions of 2-aminostilbene and its N-acyl derivatives are not governed by hydrogen bonding or steric effects. They are not explainable by the frontier molecular orbital theory, but semiempirical PM3 calculations performed on regioisomeric transition structures gave values of regioisomeric ratios well in accord with those experimentally observed.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/1778
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 10
social impact