A catalyst-free low-temperature cyanoalkylation has been developed as a general protocol for the synthesis of α-aryl(heteroaryl) nitriles.

A reaction mode on carbene bridging C–H activation (CBA) is described. In this reaction, metal carbene was produced prior to the event of C–H bond metallation. Readily available aryl dizaoesters were employed as the carbene precursors. Migratory insertion of the palladium carbene intermediate could create a modular bridging arm to promote the C–H bond palladation of tethered aldehyde moiety. Its synthetic potential was demonstrated by facile construction isocoumarin scaffold from easily accessible starting materials. Furthermore, this protocol is also amenable for late‐functionalization of complex molecules.

Herein we report the ortho‐cyanoalkylation of aryl fluoroalkyl sulfoxides with alkyl nitriles. The reaction proceeds through an “assembly/deprotonation” triggered [3,3]‐rearrangement and allows the incorporation of two valuable functional groups including the cyano group and difluoromethylthio group into arenes. As a consequence, a wide range of ortho‐cyanoalkylated difluoromethylthio arenes were produced with high efficiency under mild and environmentally friendly conditions. Remarkably, the reaction proceeds smoothly with the electron‐donating group substituted arenes which can be challenging to the reaction of non‐fluoroalkyl sulfoxides. This beneficial effect can be attributed to the unique electronegativity of fluoroalkyl substituents.

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