A Dramatic Effect of Lewis-Acid Catalysts on Nickel-Catalyzed Carbocyanation of Alkynes

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.