Gold(I)‐Catalyzed Cycloisomerization of 1,6‐Diynes: Synthesis of 2,3‐Disubstituted 3‐Pyrroline Derivatives

Abstract

A novel synthetic protocol for the preparation of the title compounds has been developed from a gold-catalyzed cycloisomerization of 1,6-diynes containing propargylic ester and arene–yne units. The corresponding nitrogen-containing five-membered heterocyclic compounds have been obtained in moderate to good yields (see scheme; DCE=1,2-dichloroethane, Tf=triflate). A plausible reaction mechanism has been proposed on the basis of deuterium labeling experiments.