Radical cyclization of fluorinated 1,3-dicarbonyl compounds with dienes using manganese(III) acetate and synthesis of fluoroacylated 4,5-dihydrofurans

YILMAZ M., YILMAZ E., PEKEL A.

Helvetica Chimica Acta, vol.94, no.11, pp.2027-2038, 2011 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 94 Issue: 11
  • Publication Date: 2011
  • Doi Number: 10.1002/hlca.201100105
  • Journal Name: Helvetica Chimica Acta
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2027-2038
  • Keywords: Cyclization reactions, Dienes, Fluorine compounds, Furans, Manganese acetate
  • Ankara University Affiliated: Yes

Abstract

Radical cyclizations of fluorinated 1,3-dicarbonyl compounds with dienes mediated by Mn(OAc)3 afforded 4,5-dihydrofurans containing difluoroacetyl, trifluoroacetyl, or heptafluorobutanoyl groups in good-to-excellent yields. Additionally, 2-(difluoromethyl)-4,5-dihydrofurans and a 4,7-dihydrooxepin derivative were obtained as unexpected products in the reaction of 4,4-difluoro-1-phenylbutane-1,3-dione with 1,3-diphenylbuta-1,3- diene. The radical cyclization of symmetrical dienes such as 2,3-dimethylbuta-1,3-diene and 1,4-diphenylbuta-1,3-diene with 1,3-diketones furnished the corresponding products in low yields. However, treatment of 1-phenylbuta-1,3-diene with 1,3-dicarbonyl compounds afforded 4,5-dihydrofurans containing fluoroacyl groups. The radical cyclizations with 3-methyl-1- phenylbuta-1,3-diene and 1,3-diphenylbuta-1,3-diene led to 4,5-dihydrofurans in good yields, since Me and Ph groups at C(3) of these dienes increase the stability of the radical intermediate. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich, Switzerland.