Enantioselective Nickel-Catalyzed α-Spirocyclization of Lactones.

Herein we report a strategy for the enantioselective synthesis of spirocycles containing all-carbon quaternary centers via nickel-catalyzed intramolecular addition of lactone enolates to aryl nitriles. The established lactone α-spirocyclization efficiently and enantioselectively forges 5-, 6-, and 7-membered rings, performing best in the synthesis of 7-membered rings (up to 90% ee). This discovery represents an expansion of the synthetic toolkit for enantioselective spirocyclization, providing access to chiral, pharmaceutically relevant spirocyclic products.