A [3 + 2]-annulation of N-Ts-α-amino aldehydes and 1,3-bispropenes permits an environment friendly, stereoselective synthesis of densely functionalized pyrrolidines. A profitable stereochemical reversal in AgOAc catalyzed [3+2] cycloaddition relies on the formation of hydrogen bonding between ligand and reactant. Simple ligand design offers an efficient and convenient route