The catalytic acvtivity of dimeric and monomeric ortho-palladated complexes [Pd{C6H2(CH2NH2-(OMe)(2),3,4}(mu-Cl)](2)(2) and [Pd{C6H2(CH2NH2-(OMe)(2),3,4}Cl(PPh3)](3), were investigated in Heck cross-coupling reaction. These complexes are more active and efficient catalysts for Heck cross-coupling reaction. The palladium complexes 2 and 3 are employed in the Heck cross-coupling reaction between styrene and acrylate with several aryl halides. High yields of corresponding C-C products, low catalyst loadings, mild reaction conditions and short reaction times are important features of these homogeneous reactions. The cross-coupled products were produced in high yields using catalytic amounts of [Pd{C6H2(CH2NH2-(OMe)(2),3,4}(mu-Cl)](2) or [Pd{C6H2(CH2NH2-(OMe)(2),3,4}Cl(PPh3)] as a thermally stable and oxygen insensitive complexes in NMP at 130 degrees C.