Site-selective olefinic C–H cyanation via alkenyl sulfonium salts

Abstract

A chemo- and regioselective olefinic C–H cyanation strategy was developed through palladium-catalyzed C(sp²)–S bond cleavage of stable alkenyl sulfonium salts with CuCN, efficiently affording multisubstituted alkenyl nitriles (acrylonitriles). This process features broad substrate scope, good chemo- and regioselectivities, and excellent functional group tolerance. The present protocol provides an alternative route to alkenyl nitriles from readily available functionalized alkenes by a site-selective interrupted Pummerer activation/palladium-catalyzed olefinic C(sp²)–S cyanation sequence.