Thermoregulated n-heptane/poly(ethylene glycol) monoalkyl ether biphasic system and its application in PETPP/Ru complex catalyzed hydrogenation

A thermoregulated biphasic system composed of n-heptane and poly(ethylene glycol) (PEG) monoalkyl ether, which underwent a reversible change from biphase to monophase regulated by temperature, was reported and used for PETPP/Ru (PETPP=P-[p-C6H4O(CH2CH2O)nH]3, 3n = 14) complex catalyzed hydrogenation. After reaction, on cooling to room temperature, the catalyst-containing poly(ethylene glycol) monoalkyl ether phase could be easily separated from the product-containing n-heptane phase by simple decantation. The catalyst could be reused directly for the next run and the catalytic activity remained almost the same within ten successive runs.