Functionalized Ethylene Oligomers as Phase-Transfer Catalysts

Article abstract of DOI:10.1021/jo00350a076

Ethylene oligomers with M_v in the range 1000-3000 containing terminal groups such as crown ethers, azacrown ethers, and phosphonium salts have been prepared and used as phase-transfer catalysts.These oligomeric catalysts have solubility properties similar to polyethylene in that they are insoluble at 25 deg C but dissolve in organic solutions at elevated (90-110 deg C) temperatures.Such oligomeric phase-transfer catalysts have activities comparable to their low molecular wait congeners and to activities reported for insoluble polystyrene-bound phase-transfer catalysts.After these oligomeric catalysts have been used in a reaction at 100 deg C, thay can be readily separated from the reaction products by cooling to form a precipitate, which can be isolated by filtration.Such catalysts may be reused without loss of activity.These catalysts are also effective in "solid-liquid" phase-transfer reactions in which an inorganic solid is suspended in a hot organic solution containing catalyst and substrate.