A simple change of solvent allows controlled and efficient switching between oxidative Heck and conjugate addition reactions on cyclic Michael acceptor substrates, catalyzed by a cationic Pd(II) catalyst system. Both reactions are ligand- and base-free and tolerant of air and moisture, and the controlled switching sheds light on some of the factors which favor one reaction over the other.
Walker, S., Boehnke, J., Glen, P. E., Levey, S., Patrick, L., Jordan-Hore, J., & Lee, A-L. (2013). Ligand and Base-free Pd(II)-Catalyzed Controlled Switching between Oxidative Heck and Conjugate Addition Reactions. Organic Letters, 15(8), 1886–1889. https://doi.org/10.1021/ol400539h