CHAPTER 3: Pd–Phosphine Precatalysts for Modern Cross-Coupling Reactions

The development and use of well-defined preformed Pd catalysts are reviewed from academic and industrial points of view. The strategies employed for the development of Pd precatalysts resulting in either L₂Pd(0) or LPd(0) are discussed with examples from industry and academia on how the properties of the ligand and the nature of the precatalyst itself can precisely affect the efficiency of a number of cross-coupling reactions. The well-defined preformed Pd catalysts often improve the selectivity and activity of selected cross-coupling reactions by reducing the metal loading and the ligand-to-metal ratios. In addition, they are often more practical to handle than the corresponding in situ system containing a Pd precursor such as Pd(dba)_x and a pyrophoric ligand such as t-Bu₃P.