Gold(I)-Catalyzed Substitution-Controlled Syntheses of Spiro[indoline-3,3 & PRIME;-pyrrolidine] and Spiro[indoline-3,3 & PRIME;-piperidine] Derivatives

Spiro[indoline-3,3 & PRIME;-pyrrolidine]and spiro[indoline-3,3 & PRIME;-piperidine] derivativeswere synthesized in a substitution-controlledmanner under the catalysis of cationic gold(I) species in the presenceof Hantzsch ester (HEH). The optimal reaction condition was determinedby screening, and the functional group tolerances of these two pathwayswere examined by readily synthetic substrates. The endo and exo selectivities of these cyclizations wereelucidated by density functional theory calculations, and a plausiblemechanism for these transformations was proposed.