Phosphine oxides as stabilizing ligands for the palladium-catalyzed cross-coupling of potassium aryldimethylsilanolates
摘要:
The palladium-catalyzed cross-coupling reaction of potassium (4-methoxyphenyl) dimethylsilanolate (K(+)1(-)) with aryl bromides has been demonstrated using triphenylphosphine oxide as a stabilizing ligand. Unsymmetrical biaryls can be prepared from a variety of aryl bromides in good yield with short reaction times. Qualitative kinetic studies compared effects of different phosphine oxides on the rate of cross-coupling and established the beneficial effect of these ligands in the reaction of electron-rich arylsilanolates. The improved yield and reproducibility of the cross-coupling of several bromides was demonstrated by direct comparison of reactions performed with and without triphenylphosphine oxide under non-rigorous exclusion of oxygen. (C) 2007 Elsevier Ltd. All rights reserved.
A Polystyrene‐Cross‐Linking Tricyclohexylphosphine: Synthesis, Characterization and Applications to Pd‐Catalyzed Cross‐Coupling Reactions of Aryl Chlorides
作者:Junya Arashima、Tomohiro Iwai、Masaya Sawamura
DOI:10.1002/asia.201801651
日期:2019.2
polystyrene‐cross‐linking tricyclohexylphosphine (PS‐TCP) was synthesized through radical emulsion polymerization of 4‐tert‐butylstyrene as a monomer and tris(trans‐4‐styrylcyclohexyl)phosphine as a threefold cross‐linker. The PS‐TCP showed enhanced ligand performance compared to the corresponding polystyrene‐triphenylphosphine hybrid PS‐TPP and tricyclohexylphosphine in Pd‐catalyzed Suzuki–Miyaura and Buchwald–Hartwig