THERMOREGULATED PHASE-TRANSFER LIGANDS AND CATALYSIS - III - AQUEOUS ORGANIC 2-PHASE HYDROFORMYLATION OF HIGHER OLEFINS BY THERMOREGULATED PHASE-TRANSFER CATALYSIS/

A series of poly(ethylene oxide)-substituted triphenylphosphines, Ph3- mP[C6H4-p-(OCH2CH2)(n)OH](m) (PEO-TPPs; la m=1, Ib m=2, Ic m=3; N=mxn= 8-25), have been prepared by the ethoxylation of mono-, di-, and tri-p -hydroxytriphenylphosphines. PEO-TPPs demonstrate an inverse temperatu re-dependent solubility in water, and possess distinct cloud points ra nge from 26 degrees C to 90 degrees C. Based on the clouding property of PEO-TPPs, a new line of aqueous/organic two-phase catalysis termed the thermoregulated phase-transfer catalysis (TRPTC) has been describe d. That is, the catalyst transfers into the organic phase to catalyze a reaction at a higher temperature, and returns to the aqueous phase t o be separated from the products at a lower temperature. Application o f this novel strategy to the rhodium-catalyzed two-phase hydroformylat ion of higher olefins gave desirable results with an average turnover frequency of 180 h(-1) for 1-dodecene. The TRPTC is suitable for carry ing out a reaction with extremely water-immiscible substrate in the aq ueous/organic two-phase system. Thus, the application scope of the cla ssical two-phase catalysis has been widened. (C) 1998 Elsevier Science B.V. All rights reserved.