Selenol

Deprotonation affords the selenolate anion, RSe−, most examples of which are highly nucleophilic and rapidly oxidized by air.

This difference can be attributed to the increased importance of stronger van der Waals bonding for larger atoms.

Three enzymes found in mammals contain selenols at their active sites: glutathione peroxidase, iodothyronine deiodinase, and thioredoxin reductase.

[3] The selenols function as reducing agents to give selenenic acid derivative (RSe−OH), which in turn are re-reduced by thiol-containing enzymes.

Methaneselenol (commonly named "methylselenol") (CH3SeH), which can be produced in vitro by incubating selenomethionine with a bacterial methionine gamma-lyase (METase) enzyme, by biological methylation of selenide ion or in vivo by reduction of methaneseleninic acid (CH3−Se(=O)−OH), has been invoked to explain the anticancer activity of certain organoselenium compounds.

[8] For example, benzeneselenol is generated by the reaction of phenylmagnesium bromide with selenium followed by acidification:[9] Another preparative route to selenols involves the alkylation of selenourea, followed by hydrolysis.