Low and high temperature bromination of 2,3-dicarbomethoxy and 2,3-dicyano benzobarrelene: unexpected substituent effect on bromination

Taskesenlioglu S., DAŞTAN A., Dalkilic E., Guney M., Abbasoglu R.

NEW JOURNAL OF CHEMISTRY, vol.34, no.1, pp.141-150, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 1
  • Publication Date: 2010
  • Doi Number: 10.1039/b9nj00372j
  • Journal Name: NEW JOURNAL OF CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.141-150
  • Karadeniz Technical University Affiliated: Yes

Abstract

The bromination of 2,3-dicarbomethoxy benzobarrelene yielded the dibromide regio- and stereospecifically arising from the aryl shift where the bromine exclusively attacks the double bond from the exo face of the double bond. High temperature bromination of this compound yielded aryl-shift products. From the low temperature bromination of 2,3-dicyano benzobarrelene, non-rearranged products were obtained along with the rearranged products. Surprisingly, we observed that the yield of non-rearranged products decreased on increasing the temperature. A possible role of the substituent was discussed using DFT calculations on model compounds.