A novel synthesis of highly substituted indole derivatives from the reaction of indole, aryl aldehydes and activated CH aides in the presence of ZnCl2, CuCl2 or AlCl3

An efficient method for the synthesis of highly substituted indole derivatives has been developed from an efficient one-pot or two steps reaction between indole, arylaldehydes activated CH acids such as acetylaceton and dimethylmalonate in the presence of ZnCl2, CuCl2 or AlCl3. The reaction provided 3-[(1H-indol-3-yl) (p-tolyl) methyl]pentane-2,4-dione 4a, 3-[(1H-indol-3-yl)(4-nitrophenyl)methyl]pentane-2,4-dione 4b, dimethyl-2-[(1H-indol-3yl)(4-nitrophenyl)methyl]malonate 4c, 2-[(1H-indol-3-yl)(p-tolyl)methyl]-1H-indole 5a, 2-[(1H-indol-3-yl)(4-nitrophenyl]methyl]-1H-indole 5b in moderate to good yields.