Gold-catalyzed formal (3 + 2) and (4 + 2) cycloadditions of alkynes to highly functionalized dihydropyrroles and tetrahydropyridines

Gold-catalyzed formal (3 + 2) and (4 + 2) cycloadditions of readily available alkynes using amino but/pent-2-enoate derivatives as annulating reagents were developed, furnishing highly functionalized 2,3-dihydropyrroles and 1,2,3,4-tetrahydropyridines.