Five diphosphinoazine palladium(II) amido complexes together with two phosphine-free and two triphenylphosphine-modified palladium(II) complexes were investigated as catalysts for the Heck reaction of styrene with 4-chlorobenzonitrile, bromobenzene and 4-bromobenzonitrile in dimethylacetamide with tributylamine as a base. The diphosphinoazine complexes competed well with the traditional catalysts; best conversions and turnover numbers were achieved with a vinyl-amide complex [(CH3OCOCH=CCOOCH3)Pd{PPh CH=C(Bu-t)NN=C(Bu-t)CH2PPh2}] giving TON of about 680 000 and TOF of 7710h(-1) in the reaction of 4-bromobenzonitrile. The TON of the chloroarene with the same complex was 729. Selectivities of the product formation were independent on the catalyst and little dependent on the substrate, the selectivity of the main product, (Z)-1,2-diarylethylene, being always over 90%. (C) 2004 Elsevier B.V. All rights reserved.