A variety of substituted β-and γ-carbolines have been prepared in moderate to excellent yields by the palladium-catalyzed annulation of internal and terminal acetylenes by the tert- butylimines of N-substituted 3-iodoindole-2-carboxaldehydes and 2-haloindole-3- carboxaldehydes, respectively. This annulation chemistry is effective for a wide range of alkynes, including aryl-, alkyl-, hydroxymethyl-, ethoxycarbonyl-, and trimethylsilyl- ...
