Aryl‐Diadamantyl Phosphine Ligands in Palladium‐Catalyzed Cross‐Coupling Reactions: Synthesis, Structural Analysis, and Application

Synthesis, temperature‐dependent NMR structure investigation and utilization of a new, stable and easily accessible aryl‐diadamantylphosphine ligand family is reported. The bulky and electron‐rich phosphorus center of the ligand enhances the catalytic activity of palladium in cross‐coupling reactions of sterically demanding ortho‐substituted aryl halides. In our study, we demonstrated the synthetic applicability of the new phosphine ligands in Buchwald‐Hartwig and tosyl hydrazone coupling reactions. Bulky diadamantyl aryl phoshine ligands were synthesized and utilized in Buchwald‐Hartwig coupling reactions of sterically demanding ortho‐substituted aryl chlorides. The ligands also showed enhanced catalytic activity in the coupling of tosyl hydrazones and aryl halides.