Substitution vs. addition. Regioselective electro-bromination of benzofuran

Hideo Tanaka, Yusuke Kawakami, Manabu Kuroboshi, Sigeru Torii

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Regioselective electro-bromination of benzofuran (2) was achieved successfully by an adequate choice of solvents and bromide salts to afford 5-bromobenzofuran (1), 5,7-dibromobenzofuran (3), and 2,3-dibromo-2,3-dihydrobenzofuran (4), respectively. Upon electrolysis of benzofuran (2) in AcOH/H2O (100/1) containing NH4Br, substitution at the C(5)-position of benzofuran (2) proceeded smoothly to afford 5-bromobenzofuran (1). After passage of totally 4 F/mol of electricity in a similar medium, 5,7-dibromobenzofuran (3) was obtained as a sole product. On the other hand, electrolysis of benzofuran (2) in CH2Cl2/H2O (1/1) and/or AcOH/H2O (10/1) in the presence of either NaBr or NH4Br afforded 2,3-dibromo-2,3-dihydrobenzofuran (4), exclusively.

Original languageEnglish
Pages (from-to)825-831
Number of pages7
JournalHeterocycles
Volume54
Issue number2
Publication statusPublished - Feb 1 2001

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Halogenation
Substitution reactions
Electrolysis
Electricity
Bromides
Salts
benzofuran
coumaran

Keywords

  • 2,3-Dibromo-2,3-dihydrobenzofuran
  • 5-Bromobenzofuran
  • Benzofuran
  • Bromination
  • Electrolysis

ASJC Scopus subject areas

  • Organic Chemistry

Cite this

Substitution vs. addition. Regioselective electro-bromination of benzofuran. / Tanaka, Hideo; Kawakami, Yusuke; Kuroboshi, Manabu; Torii, Sigeru.

In: Heterocycles, Vol. 54, No. 2, 01.02.2001, p. 825-831.

Research output: Contribution to journalArticle

Tanaka, H, Kawakami, Y, Kuroboshi, M & Torii, S 2001, 'Substitution vs. addition. Regioselective electro-bromination of benzofuran', Heterocycles, vol. 54, no. 2, pp. 825-831.
Tanaka, Hideo ; Kawakami, Yusuke ; Kuroboshi, Manabu ; Torii, Sigeru. / Substitution vs. addition. Regioselective electro-bromination of benzofuran. In: Heterocycles. 2001 ; Vol. 54, No. 2. pp. 825-831.
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