TITLE:
Aqueous-Phase, Palladium-Catalyzed Suzuki Reactions under Mild Conditions
AUTHORS:
Yueqin Cai, Gonghua Song, Zhongyuan Wu, Jiawei Zhang
KEYWORDS:
Suzuki Reaction; Ionic Liquid-Supported Diols; Phosphine-Free Ligands
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.3 No.4A,
November
22,
2013
ABSTRACT: Water-soluble ionic liquid-supported diols have been used as
phosphine-free ligands in Suzuki couplings of aryl idides/bromides/chlorides
under mild conditions in aqueous solvent. It was found that 2,2-bis((1-hexylimidazolium)-mehyl)
propane-1,3-diol hexafluorophosphate (4) in
combination with palladium (II) salts gave the most significant catalyst.
Suzuki couplings of aryl iodides/bromides occurred efficiently at room
temperature in water/acetonitrile. Notably, the reactions of hydrophilic aryl
bromides gave high yields in neat water. The catalyst PdCl2-4 was recycled five times in Suzuki
couplings in water before catalyst activity began to significantly drop. The
average yield of five cycles was >95% per cycle.