New selenenylation method. Synthesis of setenonaphthoquinones and selenoquinolinequinones mediated by phenyl selenide ion

Abstract

Treatment of diphenyl diselenide and tributylphosphine with aqueous NaOH was found to be a good method for the generation of phenyl selenide ion. A variety of 2-halogeno-1,4-naphthoquinones and halogenoquinolinequinones were efficiently converted into the corresponding seleno compounds. Selenenylation of 2,3-dichloro-1,4-naphthoquinone gave 2,3-bis(phenylseleno)-1,4-naphthoquinone. The reaction of 2-bromo-1,4-napthoquinone afforded 2,3-bis(phenylseleno)naphthoquinone in significant yield, in addition to 2-(phenylseleno)naphthoquinone as a major product. Formation of the diseleno compound was minimized when the reaction was carried out under completely oxygenfree conditions. The reaction mechanism of this selenenylation is discussed.