Synthesis, characterization, and application of palladium complexes containing 8-quinolylphosphinite ligands

Abstract

Palladium complexes containing 8-quinolylphosphinite ligands have been synthesized and characterized. Their solid state structures were determined by single-crystal X-ray diffraction. They were found to be active catalysts for Suzuki coupling reactions of phenylboronic acid and various aryl halides.

Regioselective Rhodium‐Catalyzed 1,2‐Hydroboration of Pyridines and Quinolines Enabled by the Tris(8‐quinolinyl)phosphite Ligand**

“…The two aromatic units of the coordinated quinoline moiety are slightly twisted, as indicated by the C6−C1−N1−C9 and C6−C1−C2−C3 torsion angles (−3.13(6)° and −5.85(6)° respectively). Twisting of coordinated quinoline scaffolds have also been observed in related P,N chelate complexes of rhodium and palladium [55,69–71] …”

Comparative Study of Novel Phosphordiamidite and Phosphite Ligands Used in Alkene Hydroformylation; Synthesis, Characterization, Metalation, and Catalytic Evaluation

“…As a whole, these reactions have substantially lower yields compared to the molybdenum complexes (43–83 %). Like the molybdenum complexes, monomer/dimer/oligomer and multiple coordination modes ( cis/trans ) and sites (P/N) are available for the labile metal centers , , , , , , . However, due to the relatively limited bite angles of L1 and L3 , in combination with the chelate effect, the primary isolable products were the mononuclear cis ‐[PdCl 2 (κ 2 ‐ P , N ‐ L )] complexes ( 4 and 6 ).…”

“…To expand upon this research, it is of interest to incorporate other donating groups that can act as hemilabile ligands such as pyridyl groups . Similar heterodonor P,N ligand have been used successfully in Pd‐catalyzd Suzuiki–Miyayra coupling, asymmetric Pd‐catalyzed allylic alkylation reactions, Cu‐catalyzed asymmetric conjugate 1,4‐additions, and Ir‐ or Rh‐catalyzed alkene hydrogenations,, , but very few have been studied in Rh‐catalyzed hydroformylation reactions . These catalysts are more complicated than the mixed P‐donor/ether ligands that we previously studied because the pyridyl group is more likely to competitively bind to the catalytically active Rh I metal centers .…”