“…For example, in 2010, Duan and co-workers disclosed the first palladium-catalyzed asymmetric addition of diarylphosphines to enones by using a chiral pincer ligand . Subsequently, various transition metals, including Ni, Cu, Mn, and Co, were employed with chiral ligands to construct a wide range of chiral phosphorus-based molecules described by the groups of Leung, Wang, Yin, and Harutyunyan . In addition, several metals, such as Al, Zn, Mg, Ti, Yb, and Re, could also work as chiral Lewis acids by activating unsaturated substrates to catalyze asymmetric phospha-Michael addition reactions …”