BrettPhos Pd G4 is an N-substituted 2-aminobiphenylpalladium methanesulfonate precatalyst. It is a fourth generation (G4) Buchwald precatalyst that is similar to the third generation (G3) precatalysts except that the amino group on the biphenyl backbone is methylated. This modification helps to prevent the limitations of using the third generation precatalysts. It is air, moisture and thermally-stable and shows good solubility in common organic solvents. BrettPhos Pd G4 is highly useful in cross-coupling reactions. Some of its excellent features include lower catalyst loadings, shorter reaction time, efficient formation of the active catalytic species and accurate control of ligand: palladium ratio.