[(dcpp)Ni(η2‑Arene)] Precursors: Synthesis, Reactivity, and Catalytic Application to the Suzuki–Miyaura Reaction

The complexes (Cy2PC3H6PCy2)­Ni­(η2-arene) (arene = toluene (3), naphthalene (4)) have been synthesized and studied in detail. Displacement reactions of the toluene ligand afford the complexes (Cy2PC3H6PCy2)­Ni­(η2-styrene) (5), (Cy2PC3H6PCy2)­Ni­(PhCN) (6), (Cy2PC3H6PCy2)­Ni­(CO)2 (7), (Cy2PC3H6PCy2)­Ni­(PPh3) (8), (Cy2PC3H6PCy2)­Ni­(PCy3) (9), {(Cy2PC3H6PCy2)­Ni}2(μ-H)2 (10), (Cy2PC3H6PCy2)­Ni­(η2-CO2) (11), and [(Cy2PC3H6PCy2)­Ni]2(μ,η2-1,5-COD) (12). The relative rates of ArCl oxidative addition at Ni complexes 3, 4, 6, 8, and 12 have been evaluated experimentally, and the mechanism has been calculated by DFT. Complexes 3 and 4 are efficient catalysts for the Suzuki–Miyaura reaction between chloroarenes and Ar′B­(OH)2.