Abstractmagnified imageA new synthetic route towards stable molecular‐weight enlarged monodentate phosphine ligands via ‘click’ chemistry was developed. These ligands were applied in the Pd‐catalyzed Suzuki–Miyaura coupling of aryl halides and phenyl boronic acid. The supported systems show very similar activities compared to the unsupported analogues. Moreover, recycling experiments by means of nanofiltration using ceramic nanofiltration membranes demonstrate that these systems can be recovered and reused efficiently.
Palladium-catalyzed biaryl-coupling reaction of arylboronic acids in water using hydrophilic phosphine ligands
摘要:
Hydrophilic phosphine ligands possessing a carbohydrate side-chain, such as N-(4-diphenylphosphinophenyl)methyl gluconamide (9), N-[4-(2'-dicyclohexylphosphinobiphenyl)phenylmethyl] gluconamide (10), and N-[4-(2'-di-t-butylphosphinobiphenyl)]phenylmethyl gluconamide (11), were newly synthesized to carry out palladium-catalyzed biaryl coupling of arylboronic acids in a single aqueous medium. The catalyst prepared in situ from Pd(OAc)(2) and 10 exhibited a higher efficiency than that of 9, 11, Ph2P(m-C6H4SO3Na) (TPPMS) or P(m-C6H4SO3Na)(3) (TPPTS) for representative aryl bromides, chlorides, or triflates. The catalyst prepared in situ from Pd(OAc)(2) (0.001 mol%) and 10 (0.002 mol%) achieved 96,000 TON in the reaction of p-tolylboronic acid with 4-bromoacetophenone in water. (C) 2002 Elsevier Science Ltd. All rights reserved.
Inside an artificial protein cage, a dual-metal-tagged guest protein catalyzed a linear, two-step sequential cascade reaction involving deprotection followed by hydroamination. This non-orthogonal tandem catalysis in an encapsulin nanocompartment opens an exciting toolbox for the development of compartmentalized prodrug activation reactions in biological systems.