Cyanohydrin-Mediated Cyanation of Remote Unactivated C(sp3)–H Bonds
Min Wang†§, Leitao Huan†§, and Chen Zhu*†‡
†Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou Jiangsu 215123, China
‡Key Laboratory of Synthesis Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, China
§M.W. and L.H.contributed equally.
Org. Lett., 2019, 21 (3), 821--825
A new approach for generation of alkoxy radical from the O–H bond of cyanohydrin promoted by visible-light photoredox catalysis is reported. The alkoxy radical triggers the successive remote HAT and intramolecular cyano migration, leading to the regioselective cyanation of remote C(sp3)–H bonds. The reaction exhibits a broad functional group tolerance that allows many sensitive groups to remain intact under mild conditions. To demonstrate the utility of method, the ketonitrile products are converted to other synthetically valuable compounds.