Description Application Buchwald palladacycle precatalyst with EPhos ligand for Pd-catalyzed C–N cross-coupling between primary amines and aryl halides to form 2-arylaminooxazoles. Catalyst system was reported with NaOPh (CDS001581). 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, and efficient formation of the active catalytic species and accurate control of ligand: palladium ratio. Other Notes Mechanistic Insight Leads to a Ligand That Facilitates the Pd-Catalyzed Formation of 2-(Hetero)Arylaminooxazoles and 4-(Hetero)Arylaminothiazoles