Addition-hydroamination reactions of propargyl cyanamides: rapid access to highly substituted 2-aminoimidazoles.

A valuable pharmacophore, the 2-aminoimidazole moiety, can be accessed with a variety of substitution patterns through an addition-hydroamination-isomerization sequence (see scheme; R(1),R(4),R(5)=alkyl; R(3)=alkyl, aryl; R(2)=H, alkyl, aryl). The synthesis of the propargyl cyanamide precursors through a three-component coupling enables the preparation of this important heterocyclic core structure in just three steps.