Gold-Catalyzed 1,2-Migration of Silicon, Tin, and Germanium en Route to C-2 Substituted Fused Pyrrole-Containing Heterocycles

An efficient method for the synthesis of fused pyrroloheterocycles from diverse propargyl-substituted heterocycles in the presence of Au-catalyst has been developed. The cascade transformation proceeds via alkyne-vinylidene isomerization with concomitant 1,2-shift of hydrogen, silyl, and stannyl groups. Remarkably, it was also shown that previously unknown 1,2-migration of a germyl group upon alkyne-vinylidene rearrangement occurs under these reaction conditions. This method allows for mild and efficient synthesis of diverse C-2 substituted N-containing heterocycles.