Palladium-catalyzed cyclization of o-alkynyltrifluoroacetanilides followed by isocyanide insertion: synthesis of 2-substituted 1H-indole-3-carboxamides.

A base-controlled synthesis of 2-substituted secondary and tertiary 1H-indole-3-carboxamides through PdCl(2)-catalyzed cyclization of o-alkynyltrifluoroacetanilides followed by isocyanide insertion has been developed. The reaction proceeds smoothly at ambient temperature using O(2) in air as the sole oxidant of the palladium catalyst.