A Green and Efficient Michael Addition of Indoles to α, β-unsaturated Electron-deficient Compounds and Synthesis of Bis-indolylmethanes Catalyzed by Gallium Dodecyl Sulfate [Ga(DS)3] in Water

Abstract

α, β-unsaturated electron-deficient compounds and bis-indolylmethanes were successfully synthesized by gallium dodecyl sul-fate (Ga(DS)3) catalyzed Michael addition using indoles and α, β-unsaturated ketones(or aldehyde) as reactant, respectively. The samples were characterized by 1H NMR (400 MHz), HRMS, and Electrothermal Digital Melting-point. The results showed that the α, β-unsaturated electron-deficient compounds and bis-indolylmethanes could be effectively catalyzed by using Ga(DS)3 to give the corresponding adducts in good to excellent yields in water media.