Phosphite fluorous

Catalysts Based on Fluorous Alkylphosphines, -Phosphinites, -Phosphonites, and -Phosphites... 

The fluorous alkylphosphines 2 [8, 12] and 3 [8, 13], containing one or two perfluoroalkyl tails, respectively, have also been prepared. Partition coefficients of the chiral fluorous monophosphines 3a-b were found to be lower than the values measured for the corresponding phosphines 1, which contain one extra perfluoroalkyl tail [13], In addition, fluorous phosphinites, phosphonites and phosphites 4a-e and diphosphonite 5 have become available [8, 14]. 

The behavior of rhodium catalysts generated in situ from fluorous phosphites 1-10 and Rh(acac)(CO)2 has been investigated. 

Table 1 Hydroformylation of higher aikenes under fluorous biphasic conditions with phosphites 1-6.

Other heavy terminal olefins behave similarly to 1-decene (Table 2), giving, for example, with phosphite 8, an l/b ratio of about 3.0 and an aldehyde selectivity of 95%, but the activity drops markedly going from 1-decene to 1-dodecene, presumably again due to their partial solubility with the fluorous solvent CgFi H. 

Table 2 Hydroformylation of higher alkenes under fluorous biphasic conditions with a fluorous phosphites with spacer group [13. ...

High rhodium or phosphorus leaching with rhodium-phosphite catalysts at reaction temperatures of 80 °C may be attributed to the acid-catalyzed degradation of the organophosphorus ligand - which has a larger partition coefficient in the fluorous phase-by reaction with aldehydes to give polar phosphonates. (Scheme 7.10)... 

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