Palladium-catalyzed coupling reaction of terminal alkynes with aryl iodides in the presence of indium tribromide and its application to a one-pot synthesis of 2-phenylindole.

The use of a novel PdCl(2)(PPh(3))(2)-InBr(3) reagent system to catalyze cross-coupling reactions of a variety of aryl iodides with several terminal alkynes is described. The corresponding functional alkyne derivatives were produced in good to excellent yields. Moreover, a catalytic amount of InBr(3) effectively catalyzes the intramolecular cycloaddition of 2-phenylethynylaniline to form an indole skeleton in high yield.