Nickel/Lewis Acid-Catalyzed Aryl- and Alkenylcyanation of Unsaturated Bonds

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.