Well-Defined Air-Stable Palladium HASPO Complexes for Efficient Kumada-Corriu Cross-Couplings of (Hetero)Aryl or Alkenyl Tosylates

Palladium complexes of representative heteroatom-substituted secondary phosphine oxide (HASPO) pre-ligands were synthesized and fully characterized, including X-ray crystal structure analysis. Importantly, these well-defined complexes served as highly efficient catalysts for Kumada-Corriu cross-coupling reactions of aryl, alkenyl, and even heteroaryl tosylates. Particularly, an air-stable catalyst derived from inexpensive PinP(O)H displayed a remarkably high catalytic efficacy, which resulted in cross-couplings at low catalyst loadings under exceedingly mild reaction conditions with ample scope.