2-substituted 3-aryl- and 3-heteroarylindoles by the palladium-catalyzed reaction of o-trifluoroacetanilides with aryl bromides and triflates

The palladium-catalyzed reaction of aryl and heteroaryl bromides and triflates with o-alkynyltrifluoroacetanilides affords 2-substituted 3-aryl-and heteroarylindoles usually in excellent yield. The procedure can be applied to the synthesis of 2-substituted indole-3-carboxaldehydes.