An efficient, ligand-free, transition-metal-free, direct arylation and esterification reaction of unprotected indolylcarboxylic acid derivatives with diaryliodonium salts was developed, thus providing a new entry to 2-(1H-indol-2-yl)-5-(phenylthio)-1,3,4-oxadiazole and aryl 1H-indole-2-carboxylate derivatives with good yields.
Keywords
arylation - diaryliodonium salts - indolylcarboxylic acids - esterification - transition-metal-free