A catalyst system derived from nickel and cocatalytic AlMe2Cl effects the intramolecular arylcyanation of alkenes. The reaction takes place in an exclusive exo-dig manner to give a wide range of nitriles having a benzylic quaternary carbon in good yields. Detailed investigations are described on the scope and mechanism as well as preliminary results on the asymmetric version of the reaction to provide novel access to chiral quaternary stereocenters.

Lewis-acid catalysts such as AlMe3, AlMe2Cl, and BPh3 significantly improve the efficiency of the nickel-catalyzed arylcyanation of alkynes. Electron-rich aryl cyanides, which exhibit poor reactivity in the absence of Lewis acids, readily undergo the arylcyanation reaction under the newly disclosed conditions. Excellent chemoselectivity is observed for aryl cyanides having a chloro and bromo group, allowing a single-step preparation of the synthetic intermediate of P-3622, a squalene synthetase inhibitor. Moreover, the first examples of alkenyl- and alkylcyanation of alkynes have been achieved by the nickel−Lewis acid dual catalyst.

Aryl cyanides add to norbornene and norbornadiene under nickel catalysis to give (2R*,3S*)-3-aryl-2-cyanobicyclo[2.2.1]heptanes and (2R*,3S*)-3-aryl-2-cyanobicyclo[2.2.1]hept-5-enes in good yields with a general substrate scope. On the other hand, the reaction of an aryl cyanide with triethoxy(vinyl)silane gives a Heck-type arylation product, suggesting the arylnickelation pathway in the catalytic cycle.

Lewis acid cocatalysts such as organoaluminum and -boron compounds dramatically improve the efficiency of the nickel-catalyzed arylcyanation of alkynes. Electron-rich aryl cyanides, which exhibit poor reactivity in the absence of Lewis acids, smoothly undergo the arylcyanation reaction under the nickel/Lewis acid dual catalysis. Excellent chemoselectivity is observed for aryl cyanides having a chloro or bromo group, which allows a single-step access to a synthetic intermediate of P-3622, a squalene synthetase inhibitor. The scope of the arylcyanation is also expanded to norbornadiene. Alkenylcyanation of alkynes is achieved under the nickel/Lewis acid dual catalysis to give cyano-substituted 1,3-dienes stereoselectively.