Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation

Herein, we report a Ni-catalyzed reductive coupling for
the synthesis
of benzonitriles from aryl (pseudo)­halides and an electrophilic cyanating
reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable,
carbon-bound electrophilic CN reagent that does not release cyanide
under the reaction conditions. A variety of medicinally relevant benzonitriles
can be made in good yields. Addition of NaBr to the reaction mixture
allows for the use of more challenging aryl electrophiles such as
aryl chlorides, tosylates, and triflates. Mechanistic investigations
suggest that NaBr plays a role in facilitating oxidative addition
with these substrates.