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.
Key words
elemental selenium - sodium borohydride - alkylation - alkyl halides - benzyl halides
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6 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.
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