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

(I(t)Pe)AuBr(2)(N-imidate) complexes, prepared in high yield by oxidative bromination, are active catalysts for 1,5-enyne cycloisomerization. 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(CF(3))(3))(4)]).