Catalytic Dearomative Spirocyclization via Gold Carbene Species Derived from Ynamides: Efficient Synthesis of 2-Azaspiro[4.5]decan-3-ones

An intramolecular catalytic dearomatization of phenols via gold carbene species proceeded to provide 2-azaspiro[4.5]decan-3-ones. The use of NHC ligand and water as a co-solvent was critical for achieving high reactivity. This reaction did not require hazardous diazo compounds as carbene sources and proceeded even under air. The obtained spirocyclic product could be readily transformed into a gabapentin derivative by hydrogenation and deprotection.