Catalytic systems trans-[PdCl2(DEA)(2)]/DEA and trans-[PdCl2(DEA)(2)]/[DEA][HAc], used in the model reaction of methyl methacrylate with iodobenzene, 4-iodoanisole, and bromobenzene, provide homogeneous catalysis, good regioselectivity and excellent stereoselectivity. The major product of the regioselective reaction is internal olefin. In all examined cases the only stereoisomer of the internal olefin methyl 3-phenyl-2-methylpropenoate is the E-isomer, whereas the only stereoisomer of the double arylated reaction product methyl 2-benzyl-3-phenylpropenoate is the Z-isomer. A DFT study, which investigates mechanistic aspects of migratory insertion, beta-hydride elimination and reductive elimination of this phosphine-free Heck reaction, is in agreement with our experimental findings. (C) 2012 Elsevier B.V. All rights reserved.