The chlorination of indoles by copper(II) chloride
Abstract
The reaction of indoles with copper(II) chloride has been studied in acetonitrile. At low copper(II):indole ratios, dimers are formed in the presence of dioxygen, oxygenated products are obtained, and at large copper(II) :indole ratios, pyrrole ring-chlorinated products are formed in yields of up to 92 %. The reactions are postulated to proceed via the radical cations of the indoles formed in an electron-transfer reaction.