Triphenylphosphine monosulfonate

Equation 2.6. Scrambling of triphenylphosphine monosulfonated sodium salt under hydroformylation... 

The use of water-soluble metal catalysts for the hydrogenation of thiophenes in aqueous biphasic systems has been primarily introduced by Sanchez-Delgado and coworkers at INTEVEP S.A. [61]. The precursors RuHC1(TPPTS)2(L2) (TPPTS=triphenylphosphine trisulfonate L=aniline, 1,2,3,4-tetrahydroquinoline) and RuHC1(TPPMS)2(L2) (TPPMS=triphenylphosphine monosulfonate) were... 

The water-soluble complex [RuCl(triphenylphosphine monosulfonate) (=C=CHPh)][Na]2 (L3) made possible the following cascade ring-opening/ cross-metathesis reaction (Eq.9) [72]. 

The general flow scheme for this alternative is shown in Figure 15. After the homogeneous reaction, catalyzed for instance by a rhodium catalyst containing triphenylphosphine monosulfonic acid as complex ligand, the solubilizer methanol is distilled off. The catalyst system now becomes insoluble and is separated by extraction with water in the third unit. The products C and D, in this case the aldehydes, can be separated as the second liquid phase. After evaporation of the aqueous catalyst solution to dryness (unit 4) the catalyst is dissolved in the solvent methanol for a new reaction step (unit 5). 

The Combination of Triphenylphosphine Monosulfonate (TPPMS) and Polar Solvents... 

This was the starting point of Kimtz s work at Rhone-Poulenc, trying to transfer rhodium catalysts from the organic monophase to the aqueous biphase not by triphenylphosphine monosulfonate (which had been tried by Joo or WiUdnson (4, 8]) but by TPPTS. From 1974 onward, the scope of different reactions using biphasic catalyst systems was tested in laboratory-scale experiments. Among these were... 

In the case of the hydroformylation reaction, 46.5 mg (0.180 mmol) [Rh(acac)(CO)2 and 1.31 g [Prmim][TPPMS] (Prmim = l-propyl-3-methylimidazolium TPPMS = triphenylphosphine monosulfonate) were dissolved in 12 mL IL in a 30 mL CSTR. 

Sulfonated triphenylphosphine [TPPTS (triphenylphosphine, m-trisulfonated) tri(m-sulfophenyl)phosphine] (II-l) and monosulfonated triphenylphosphine [TP-PMS (triphenylphosphine, monosulfonated) 3-(diphenylphosphino)benzenesul-fonic acid] (II-2) are commercially available ligands and their sodium salts are water-soluble [15]. The Na salt of the ligand TPPTS is very soluble and may be too soluble in water, hence moderately soluble TPPMS is preferred. Another water-soluble phosphine is 2-(diphenylphosphinoethyl)trimethyl ammonium halide (II-11) [16]. A number of other water-soluble phosphines are now known (Table 1.2). Pd complexes, coordinated by these phosphines, are soluble in water, and Pd-catalyzed reactions can be carried out in water, which is said to have an accelerating effect in some catalytic reactions. 

Figure 15.1 Typical hydroformylation monophosphine ligands TPPTS (3, triphenylphos-phine trisulfonate, sodium salt), TPPTIM (4, triphenylphosphine trisulfonate, l-butyl-2,3-dimethylimidazolium salt), and TPPMS (5, triphenylphosphine monosulfonate, sodium salt).

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