Palladium-Catalyzed Sequential Reactions via Allene Intermediates for the Rapid Synthesis of Fused Polycyclic Pyrrole Derivatives

In this paper, we report a novel sequential reaction sequence consisting of a series of processes including Sonogashira coupling, propargyl-allenyl isomerization, [3 + 2] cycloaddition, denitrogenation, and highly selective biradical coupling reaction, providing an efficient synthesis of fused polycyclic pyrrole derivatives. The reaction features one C-C bond and two C-N bonds formed to construct the pyrrole unit, together with two rings efficiently assembled in one stroke.