Gold-Catalyzed Reactivity Reversal of Indolizidinone-Tethered β‑Amino Allenes Controlled by the Stereochemistry

The controllable cyclization reaction of indolizidinone-tethered β-amino allenes has been achieved through gold catalysis. The expected cycloisomerization of the <i>syn</i>-isomer sharply contrasts to the unprecedented bis­(azacyclization)–spirocyclization sequence of the epimeric <i>anti</i>-isomer, offering highly selective access to enantiopure fused and spiranic azapolycycles