Gold- and silver-mediated cycloisomerizations of N-propargylamides

Substituted N-propargylamides have proven to be valuable substrates for alkyne-activated cycloisomerization reactions. N-Tosyl-N'-propargylurea underwent reaction with AuCl3 to give the corresponding dihydroimidazolone, while N-propargyl-3-oxobutanamides and esters were used to construct furanyl fused pyrrolldinones and dihydrofuranones via Ag(I)-mediated alkyne activation.