The synthesis of phosphoiminoBINOLs L1-L4 can be readily achieved through imine formation between 3,3′-formyl BINOL and the corresponding aminophosphine (Fig. 2C). The isopropyl-substituted phosphoiminoBINOL (L1) was stable to handling under air, and showed a high affinity with various soft metal salts. When 2 mol equiv. of Pd(OAc)2 was added to L1, the formation of a dinuclear palladium complex took place, as demonstrated by ESI-MS: an ion peak was detected at m/z = 1117.1705 in CH2Cl2, and this was attributed to [L1(−2H) + Pd2(OAc)]+. Fine crystals were obtained from a CH2Cl2 solution, and the structure of phosphoiminobinaphthoxy (L1)-Pd2(OAc)2 was determined by X-ray crystallographic analysis (Fig. 3).Figure 3X-ray structure of L1-Pd2 (CCDC 1543349).