Pd nanoparticles in the thermoregulated ionic liquid and organic biphasic system: An efficient and recyclable catalyst for heck reaction

A thermoregulated ionic liquid and organic biphasic system composed of ionic liquid [CH₃(OCH₂CH₂)₁₆N ⁺Et₃][CH₃SO₃ ^-] (IL _PEG750) with IL_PEG750-stabilized Pd nanoparticles and organic solvents, which allows for not only a highly efficient homogeneous catalytic reaction, but also an easy biphasic separation and reuse of catalyst attributed to the thermoregulated phase-transition property of the system, was employed for Heck reaction. The IL_PEG750-stabilized Pd nanoparticle catalyst exhibited high efficiency, more importantly, after reaction the Pd nanoparticle catalyst could be separated from products by simple phase separation and recycled for six times without evident loss of activity. Graphical Abstract: A thermoregulated ionic liquid and organic biphasic system containing [CH₃(OCH₂CH₂)₁₆N ⁺Et₃][CH₃SO ₃ ^- ] (IL_PEG750)-stabilized Pd nanoparticles was applied to Heck reaction for the first time. The Pd nanoparticle catalyst exhibited high efficiency and good recyclability.[Figure not available: see fulltext.]