Catalytic Cyanation of Carbon‐Carbon Triple Bonds Through a Three‐Component Cross‐Coupling Reaction under Nickel Catalysis

A nickel‐catalyzed three‐component coupling reaction through cyanation of a carbon‐carbon triple bond is described. A nickel(0) complex effectively catalyzes a sequential coupling reaction between allenes, alkynes and hydrogen cyanide from acetone cyanohydrin in a highly regio‐ and stereoselective fashion. The trigger for this reaction is hydronickelation to allenes. The initial hydride attack predominantly occurs at the central carbon of the allene to give a π‐allylnickel(II) species. Subsequent syn ‐carbometalation connects a β‐carbon of alkynoates and a less‐hindered carbon of the allylnickel(II) species, and the corresponding cyanoalkenes are obtained as a single stereoisomer without any another organometallic reagents as a coupling partner.