Lewis Acid mediated aminobenzannulation reactions of δ-ketoalkynes: Synthesis of 1-aminocarbazoles and 9-aminopyrido[1,2-α]indoles
2-Acyl-N-propargylindoles 1 and 2-acyl-3-propargylindoles 5 undergo aminobenzannulation reactions with pyrrolidine in the presence of an appropriate Lewis acid to give 9-aminopyrido[1,2-α]indoles 6 and 1-aminocarbazoles 7, respectively. The selection of t
Intramolecular cyclization of δ-iminoacetylenes: A new entry to pyrazino[1,2-a]indoles
The synthesis of the pyrazino[1,2-a]indole nucleus was achieved by intramolecular cyclization of several 2-carbonyl-1-propargylindoles in the presence of ammonia. The reaction conditions were optimized using microwave heating and a pool of catalysts. Cycl