DFT studies on the mechanism of Pd(II)-catalyzed intermolecular 1,2-diamination of conjugated dienes

The reaction mechanism of the palladium(II)-catalyzed addition of urea to dienes to form 1,2-diamine was studied using the B3LYP density functional theory (DFT) method. The results indicate that the first C-N sigma-bond formation is the rate-determining step, and that the covalent bonds are formed favorably by the terminal carbon atoms of dienes and nitrogen atom. The Pd(NCMe)-catalyst may significantly lower the energy barrier of the rate-determining step from the nonligand Pd(II)-catalyst counterpart. The results are in strong support of a recent experiment. Copyright (C) 2008 John Wiley & Sons, Ltd.