nickel/Lewis acid (LA) cooperative catalysis to give beta-cyano-substituted acrylates and acrylamides, respectively, in highly stereoselective and regioselective manners. The resulting adducts serve as versatile synthetic building blocks through chemoselective transformations of the ester, amide, and cyano groups as demonstrated by the synthesis of typical structures of beta-cyano ester, beta-amino
Selective CC bond cleavage: A catalyst consisting of nickel(0)/DPEphos and BPh3 is highly effective for the addition of polyfluorobenzonitriles to alkynes through selective activation of the CCN bond over the CH or CF bonds. The addition reaction is applicable to the sequential insertion of two different alkynes into CCN and CH bonds (see scheme).
A nickel catalyst coordinated by trimethylphosphine is found to effect the addition reaction of Ar-CN bonds in aromatic nitriles across alkynes to give rise to various beta-arylalkenenitriles.
A nickel catalyst prepared from Ni(cod)(2) and PMe3 is found to effect arylcyanation reaction of alkynes. namely cleavage of a C-CN bond of an aryl cyanide followed by addition of each fragment across an alkyne. A wide range of functional groups in aryl cyanides tolerated the catalysis, giving variously functionalized beta-arylalkenenitriles stereoselectively. (c) 2006 Elsevier Ltd. All rights reserved.