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 -allylnickel(II) species. Subsequent syn-carbometalation connects a -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.