Over the years, azaindoles and diazaindoles have generated an increased interest due to their structural similarities with indoles and their potential as pharmacologically active compounds. A mild and efficient methodology has been developed for the synthesis of azaindoles and diazaindoles. This novel procedure includes a palladium-catalyzed reductive N-heteroannulation as the key step. This methodology was successfully applied to the synthesis of 4-azaindole, 2-phenyl-5-azaindole, 2-phenyl-6-azaindole, and 7-azaindole. In addition, this method was efficiently utilized to synthesize 2-phenyl-4,6-diazaindole and 2-phenyl-4,5-diazaindole. The reductive N-heteroannulation was carried out in the presence of Pd(dba)2, 1,10-phenanthroline, and carbon monoxide (6 atm) in DMF at 120°C.;A number of carbazole alkaloids have been synthesized and are of great interest due to the wide array of biological activity these compounds exhibit. Advanced intermediates of carbazole alkaloids were prepared utilizing a Stille coupling to afford the cyclization precursors, 2-(2-nitroarene)-2-cyclohexenones. These precursors were subjected to the palladium-catalyzed cyclization developed, smoothly affording the desired carbazolones. Utilizing this method, the cyclization precursor of an advanced carbazolone intermediate of (+)-Aspidospermidine was obtained in good yield. Reductive cyclizations of Stille coupling products, 2-(2-nitroarene)-2-cyclohexenones, using Pd/C and 1 atm of hydrogen yielded the corresponding 1,2,3,4-tetrahydrocarbazole derivatives
