An efficient Negishi cross-coupling reaction catalyzed by nickel(II) and diethyl phosphite

A combination of diethyl phosphite-DMAP and Ni(II) salts forms a very effective catalytic system for the cross-coupling reactions of arylzinc halides with aryl, heteroaryl, and alkenyl bromides. chlorides. triflates. and nonaflates. The choice of solvent is quite important and the mixture of THF-N-ethylpyrrolidinone (NEP) (8: 1) was found to be optimal. The reaction usually requires only 0.05 moll % of NiCl2 or Ni(acac)(2) as catalyst and proceeds at room temperature within 1-48 h. (c) 2006 Elsevier Ltd. All rights reserved.