Allylcyanation of alkynes: regio- and stereoselective access to functionalized di- or trisubstituted acrylonitriles

Allyl cyanides are found to add across alkynes in the presence of a nickel catalyst prepared from Ni(cod)2 and P(4-CF3-C6H4)3 in situ to give variously functionalized di- or trisubstituted acrylonitriles in highly stereoselective manners possibly via a pi-allylnickel species as an intermediate. alpha-Siloxyallyl cyanides also react at the gamma-position of a cyano group with both internal and terminal alkynes having various functional groups to give silyl enol ethers, which give the corresponding aldehydes or ketones upon hydrolysis.