Gold-catalyzed Alkylation Reactions Of Indoles With Alkynes

The alkylation reaction is one of the most important C-C bond forming reactions in organic chemistry. Recently, the synthesis of β-indole derivatives has received much attention due to their important biological activities and key roles as versatile building bocks in the synthesis of natural products. Therefore, a variety of methods have been reported for the preparation of this kind of compounds. The development of new, more efficient, more selective synthetic methods of β-indole derivatives continues to receive considerable attention for organic chemists. Although there are many publications on transition-metal-catalyzed synthesis of indole derivatives, only few reports on gold-catalyzed reactions of indoles has been published. In this context, we studied gold (I) catalyzed Friedel-Crafts alkylations of indoles with alkynes, which resulted in 3 -indole derivatives in high yields. The effects of co-catalysts and solvents on this reactions have been examined. A series of β-indole derivatives were synthesized under the nitrogen atmosphere, with the use of Ph₃PAuCl-AgC104 as the catalyst and acetonitrile as the solvent. All target compounds were characterized by ¹HNMR and ¹³CNMR.