Copper-catalyzed enantioselective decarboxylative cyanation of β,γ-unsaturated carboxylic acids to access chiral allyl nitriles

Copper-catalyzed asymmetric radical cyanation reactions have emerged as a powerful platform for construction of a variety of enantioenriched cyano-containing compounds under mild conditions. Herein, we report a copper-catalyzed enantioselective decarboxylative cyanation of readily available β,γ-unsaturated carboxylic acids promoted by a hypervalent iodine(III) reagent. The key allyl radical can be efficiently formed through single-electron reduction of in-situ-generated phenyliodine(III) dicarboxylates by Cu(I) species. This protocol features mild conditions, wide substrate scope, and functional group tolerance, producing a diverse range of chiral allyl nitriles in moderate to good yields and with high regio- and enantioselectivities. The enantioenriched allyl nitrile products can be used for the preparation of various synthetically useful chiral intermediates through simple transformations.