Convenient and efficient Suzuki–Miyaura cross-coupling reactions catalyzed by palladium complexes containing N,N,O-tridentate ligands

Mixed-donor N,N,O-tridentate ligands for palladium-catalyzed Suzuki reactions

“…The yield decreased rapidly as the Pd:ligand ratio approached 1:2 (entries 6 and 7). This can be explained by the formation of the catalytically inert, bis ligand chelated complex 8, as shown in Scheme 3 [16,17].…”

“…Thermal stability as well as insensitivity of N,N,O-tridentate ligands in efficient Pd-catalyzed Suzuki reactions was found by Patil et al [17], Whilst Mohanty et al [18] reported several N,N,O,O-tetradentate ligands (Scheme 1, compounds 4, 5 and 6) in the Pd-catalyzed coupling of aryl chlorides with arylboronic acids. Yang et al [19] proposed Pd(OAc) 2 -catalyzed aerobic Suzuki reactions of aryl chlorides promoted by an N,O-bidentate ligand formed in situ via solvent hydrogen bonding.…”

A Quantum-Chemical DFT Approach to Elucidation of the Chirality Transfer Mechanism of the Enantioselective Suzuki–Miyaura Cross-Coupling Reaction

“…The different possibilities of transmetallation reaction that may take place in the second stage of the asymmetric SM reaction were assessed. It has been shown that the transmetallation step in a typical SM coupling reaction does not proceed without the nucleophilic additive, which enhances the electron density at the boron atom through its coordination and formation of boron-ate adduct [20,21,24,65,66]. In an aqueous solution of inorganic bases, the role of this nucleophile may be played by the hydroxyl anion.…”

“…Since aryl-aryl bond forming cross-couplings are mechanistically quite similar, in our studies on enantioselective coupling we concentrated on the Suzuki-Miyaura reaction, which is usually applied as a method of first choice. The mechanics of the nonstereocontrolled Suzuki-Miyaura (and a few other couplings) reaction catalysed by complexes of nonchelating monophosphines has been studied in detail (Scheme 1) [20][21][22][23][24][25][26][27][28][29] and can be extrapolated to reactions catalysed by transition metal complexes of different types and to stereoselective transformations. At …”

Efficient palladium-catalyzed Suzuki cross-coupling reaction with β-ketoamine ligands

“…In contrast, phosphine-free ligands, such as tridentate [17][18][19][20] and bidentate ligands containing N, O and S atoms, are typically inexpensive, easily prepared and moisture-and air-stable. Among them, β-ketoamine ligands, previously used as excellent candidates for olefin and ε-caprolactone polymerization [42,43], have recently been applied to Suzuki cross-coupling [38][39][40][41].…”