Regioselectivity observed in manganese(III) acetate mediated addition of acetylacetone to various alkenes: mechanistic and theoretical studies

Ceyhan S., Cetinkaya Y., AKDAĞ A., BALCI M.

TETRAHEDRON, cilt.72, sa.43, ss.6815-6824, 2016 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 72 Sayı: 43
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1016/j.tet.2016.09.015
  • Dergi Adı: TETRAHEDRON
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.6815-6824
  • Anahtar Kelimeler: Cycloaddition, Substituent effects, Oxidation, Regioselectivity, Mn(OAc)(3), 1,3-DICARBONYL COMPOUNDS, DIASTEREOSELECTIVE SYNTHESIS, ORGANIC-SYNTHESIS, WITTIG REACTIONS, GAMMA-LACTONES, DIHYDROFURANS, OXIDATION, 3-CYANO-4,5-DIHYDROFURANS, IODOENOLCYCLISATION, DERIVATIVES
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Various alkenes substituted at the 1,2-positions by 2-thiophenyl, 3-thiophenyl, and phenyl substituted by electron-withdrawing and electron-donating groups were treated with acetylacetone in the presence of Mn(OAc)(3) in acetic acid. In cases where the thiophene ring was connected at the C-2 carbon atom to the double bond, a single regioisomer was formed whereas in case of substitution at the C-3 positions two regioisomers were formed. Stilbene derivatives also gave two regioisomers under the same reaction conditions. However, 1-methoxy-4-(4-nitrostyryl)benzene provided a single cycloaddition product. The observed regioselectivity was discussed in terms of atomic charge distribution on the olefinic double bond carbon atoms. Furthermore, activation barriers for transition states were calculated. (C) 2016 Elsevier Ltd. All rights reserved.