Synthesis of Triazolo- and Oxadiazolopiperazines by Gold(I)-Catalyzed Domino Cyclization: Application to the Design of a Mitogen Activated Protein (MAP) Kinase Inhibitor.

An efficient method for the synthesis of [1,2,4]triazolo[4,3- a]piperazine derivatives was established based on a gold(I)-catalyzed domino cyclization of an amidrazone substrate with a terminal alkyne. The amidoxime congeners were converted into [1,2,4]oxadiazolo[4,5- a]piperazine derivatives in the presence of a gold catalyst. The oxadiazolopiperazine is a promising scaffold for the design of novel inhibitors against p38 mitogen activated protein kinase (MAP kinase).