Enantioselective Nickel-Catalyzed α-Spirocyclization of Lactones
Allison M Stanko1, Melissa Ramirez1, Adrian J de Almenara1
1The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.
Abstract:
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.
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