Reusable and Efficient Pd(OAc)₂/TBAB/PEG-400 System for Suzuki-Miyaura Cross-Coupling Reaction under Ligand-Free Conditions

The combination of Pd(OAc)2, TBAB and PEG-400 [poly(ethylene glycol-400)] was introduced as a reusable and efficient system for the Suzuki-Miyaura cross-coupling reaction. In the presence of 0.01 to 3 mol% of Pd(OAc)2, 10 mol% of TBAB, 2 equivalents of K2CO3 and 4 g of PEG-400, a number of aryl halides were coupled with arylboronic acids efficiently to afford moderate to excellent yields of the corresponding products under ligand-free conditions. Moreover, the system can be reused three times without any loss of catalytic activity.