Remarkable anion effects uncovered in the development of a Au(III)-catalyzed tandem nucleophilic substitution-1,5-enyne cycloisomerization process

(I(t)Pe)AuBr2(N-imidate) complexes, prepared in high yield by oxidative bromination, are active catalysts for 1,5-enyne cyclo-isomerization. An efficient tandem nucleophilic substitution-1,5-enyne cycloisomerization is promoted by these novel Au(III) precatalysts. Catalyst efficacy is affected by the imidate ligand and the silver salt used (e. g. Ag[Al(OC(CF3)(3))(4)]).