Regioselective intramolecular cyclization of o -alkynyl arylamines with the in situ formation of ArXCl to construct poly-functionalized 3-selenylindoles.

In this article, a practical and metal-free method for the synthesis of poly-functionalized 3-selenyl/sulfenyl/telluriumindoles from o -alkynyl arylamines has been achieved. In this protocol, the in situ formation of selenenyl chloride, sulfenyl chloride or tellurenyl chloride is considered as the key intermediate and the 3-selenyl/sulfenyl/telluriumindoles can be obtained in good to excellent yields. Furthermore, the product 2-phenyl-3-(phenylselanyl)-1-tosyl-1 H -indole can be selectively oxidized to compounds 2-phenyl-3-(phenylseleninyl)-1-tosyl-1 H -indole and 2-phenyl-3-(phenylselenonyl)-1-tosyl-1 H -indole in good yields.