Amphiphilic Polymer Supported NHC Palladium Complex for Suzuki-Miyaura Coupling

Significance

The authors prepared two types of amphiphilic polymer supported N-heterocyclic carbene (NHC) precursor resin 1 from polyethylene glycols of different molecular weight (PEG 200, PEG 600). These PS-PEG-NHC precursor resins 1 were treated with Pd(OAc)₂ and t-BuOK as a base for the in situ deprotonation of imidazolium salt to give the PS-PEG-NHC-Pd complexes 2. The Suzuki-Miyaura cross-coupling reactions of various aryl iodides and aryl bromides withphenylboronic acid in the presence of Cs₂CO₃ in water gave the corresponding products in 76-99% yield by use of the PS-PEG 600 catalyst 2. The catalyst was readily recovered from the reaction mixture by simple filtration and was reused five times.