Synlett 2004(10): 1751-1754  
DOI: 10.1055/s-2004-829554
LETTER
© Georg Thieme Verlag Stuttgart · New York

Conditions-Driven Selective Synthesis of Selenides and Selenols from Elemental Selenium

Alain Krief*a, Mahmoud Trabelsia, Willy Dumonta, Michel Derocka,b
a Laboratoire de Chimie Organique de Synthèse, Département de Chimie, Facultés Universitaires Notre-Dame de la Paix, 61 rue de Bruxelles, B-5000 Namur, Belgium
Fax: +32(81)724536; e-Mail: alain.krief@fundp.ac.be;
b Fonds pour la Formation à la Recherche dans l’Industrie et l’Agriculture, 5 rue d’Egmont, Bruxelles 1000, Belgium
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Publication History

Received 16 April 2004
Publication Date:
15 July 2004 (online)

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Abstract

Sodium borohydride in DMF is able to reduce elemental selenium in the presence of ethanol. Alkylation of the species resulting from the reaction of 2:1 molar equivalents of NaBH4/Se allows the selective synthesis, under very mild conditions, of symmetrical dialkyl selenides. Addition of formic acid, prior to that of the electrophile, permits the synthesis of the corresponding selenols.

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In the course of this work we have found that whereas decyl selenol 3a does not react with decyl bromide or methyl iodide in DMF, it can be alkylated if the reaction is carried out in the presence of sodium formate (1 equiv). The reaction is quite slow (20 °C, 20 h) and provides competitively some diselenides 2 resulting from the oxidative coupling of the selenolates.