Selenol

In organic chemistry, a selenol is a chemical compound that contains the functional group composed of a selenium atom bonded to a hydrogen atom (-SeH). Volatile molecular weight selenols have highly offensive odors and are easily oxidized to diselenides, compounds containing an Se-Se bond. The essential amino acid selenocysteine is a rare naturally occurring selenol. Benzeneselenol (selenophenol) is one of the more common selenols used in organic synthesis, its oxidized derivative is diphenyl diselenide.
Benzeneselenol is easily prepared by the reaction of the Grignard reagent of bromo benzene with selenium powder. [D. G. Foster, "Organic Syntheses" 24 (1944); 89] Its oxidation by Br₂ yields diphenyl diselenide.
A common way for the preparation of selenols is the nucleophilic substitution of a leving group like an alkyl bromide by seleno urea, and subsequent hydrolysis.

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