Vanadium-catalyzed sulfenylation of indoles and 2-naphthols with thiols under molecular oxygen.
Vanadium oxyacetylacetonate [VO(acac)(2)] works as a catalyst for the direct synthesis of 3-sulfanylindoles from indoles and thiols under an atmospheric pressure of molecular oxygen as a reoxidant. For example, the reaction of 2-phenylindole with benzenethiol in the presence of a catalytic amount of VO(acac)(2), potassium iodide, and 2,6-di-tert-butyl-p-cresol in chlorobenzene under molecular oxygen proceeds to afford 2-phenyl-3-(phenylsulfanyl)indole in 86% yield. This catalytic system can also be applied to 2-naphthols instead of indoles to give the corresponding 1-sulfanyl-2-naphthols in up to 57% yield.
Maeda
Yasunari
Y
Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
Koyabu
Motonori
M
Nishimura
Takahiro
T
Uemura
Sakae
S