General and direct synthesis of 3-aminoindolizines and their analogues via Pd/Cu-catalyzed sequential cross-coupling/cycloisomerization reactions

An efficient and one-step synthesis of 3-aminoindolizines or benz[e]indolizines from the reactions of propargyl amines or amides with heteroaryl bromides was developed. This methodology is realized by a tandem reaction using Pd/Cu catalysts, which could catalyze coupling and cycloisomerization reactions in the same vessel.