Light, medium, and heavy fluorous triarylphosphines exhibit comparable reactivities to triphenylphosphine in typical reactions of triarylphosphines.
[reaction: see text] The relative reactivities of triphenylphosphine (PPh(3)) and three fluorous triarylphosphines [(p-R(F)(CH(2))(2)C(6)H(4))(n)PPh(3)(-)(n), where n = 1-3] have been compared in internal competition experiments. Product ratios were determined by (31)P NMR spectroscopy. The four phosphines have about the same reactivities in oxidation, alkylation, and Staudinger reactions and give comparable yields in a preparative Mitsunobu reaction. Previously observed rate and yield differences in Staudinger reactions of the fluorous phosphines are attributed to solubility effects, not reactivity differences. A light fluorous phosphine [(p-C(8)F(17)(CH(2))(2)C(6)H(4))PPh(2)] outperforms a commercially available resin-bound phosphine in a competitive benzylation experiment by a factor of about 4.
Curran
Dennis P
DP
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. curran@pitt.edu
Wang
Xiao
X
Zhang
Qisheng
Q
D002384:Catalysis; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010720:Phosphines / Q000737:chemistry*
D006845:Hydrocarbons, Fluorinated; D007202:Indicators and Reagents; D010720:Phosphines