Syntheses of functionalized 1,4-disubstituted gamma-carbolines

We report the complete synthesis of a variety of 1,4-disubstituted gamma-carbolines. These compounds are of particular interest for their involvement in many biological processes and are believed to possess various medicinal activities. A large number of N-tosylaldimines were condensed with indoles affording an array of 3-aminomethyl indoles. Subsequent additions, followed by intramolecular cyclization, afforded an array of 1,2-dihydro-3H-gamma-carbolones in good yield. Upon subsequent aromatization, the corresponding fully aromatic functionalized 1-aryl-4-hydroxy-gamma-carbolines resulted.