Monosulfonated triphenylphosphine TPPMS

A ligand with great potential for hydroformylation of higher, terminal alkenes is monosulfonated triphenylphosphine, tppms, that was studied by Abatjoglou, also at Union Carbide [12] (section 8.2.6). In this system hydroformylation is carried out in one phase that is worked up afterwards by adding water, which gives two phases to separate catalyst and product. 

As a polar solvent for the catalyst ethylene carbonate (EC), propylene carbonate (PC) and acetonitrile were used. Tricyclohexylphosphine, triphenyl-phosphine and the monosulfonated triphenylphosphine (TPPMS) were investigated as ligands with Pd(acac)2 as the precursor. Cyclohexane, dodecane, p-xylene and alcohols (1-octanol, 2-octanol and 1-dodecanol) were tested as non-polar solvents for the product. To determine the distribution of the product and of the catalyst, the palladium precursor and the hgand were dissolved in the polar solvent and twice as much of the non-polar solvent was added. After the addition of 5-lactone, the amounts of the product in both phases was determined by gas chromatography. The product is not soluble in cyclohexane and dodecane, more than 99% of it can be found in the polar catalyst phase. With the alcohols 1-octanol, 2-octanol and dodecanol about 50 to 60% of the 5-lactone are located in the non-polar phase. With p-xylene biphasic systems can only be achieved when EC is used as the polar solvent and even in this solvent system one homogeneous phase is formed at a temperature higher than 70 °C. In a 1 1 mixture of EC and p-xylene about 50 to 60% of the product is contained in the polar phase. 

At room temperature the Rh-catalyzed hydroformylation of butadiene [22] and of 1-pentene is possible (eq. (2)) [10 a]. In the latter case, [Rh(CO)2(acac)] in the presence of triphenylphosphine achieves slightly higher turnover frequencies (TOF) as compared to reactions in toluene. The product ratio of Ao-aldehyde was not influenced by the solvent. The use of the monosulfonated triphenylphosphine (tppms), however, reduced the activity of the catalyst drastically although its use allowed a more efficient recycling of the catalyst [10 a]. 

The sulfonation of triphenyl phosphine with fuming sulfuric acid can give three possible products monosulfonated triphenylphosphine (TPPMS), disulfonated triphenylphosphine (TPPDS), and TPPTS 1, depending on the reaction conditions (Figure 9). Using this method many sulfonated aryl phophines have been prepared (2b,... 

With this last point in mind, the synthesis of mono-, bis- and tra-sulfonated triphenylphosphine will be described, but the same methodology can be applied to the preparation of other sulfonated arylphosphines. In general, these phosphines are made by direct sulfonation using fuming sulfuric acid (oleum) [21], The extent of sulfonation is determined by the SO3 strength, as well as factors such as the temperature and time of the reaction. The monosulfonated phosphine (tppms) is prepared using oleum of 20% SO3 strength, with typically 30% SO3 used... 

Hydrogenation reactions in water have been extensively studied and many of the water-solubilizing ligands described in Chapter 5 have been tested in aqueous-organic biphasic hydrogenation reactions. One of the earliest catalysts used was the water-soluble analogue of Wilkinson s catalyst, RhCl(tppms)3 (tppms = monosulfonated triphenylphosphine), but many other catalysts have since been used including [Rh(cod)(tppts)2]+, [Rh(cod)2]+ and [Rh(acac)(CO)2]+ (cod = cyclooctadiene). 

It occurred to us that ionic interactions might be a highly suitable binding motif to enforce the formation of heterobidentate ligand combinations [48[. The assembly ligand 14 /IS has been formed from the well-known TPPMS (14, monosulfonated triphenylphosphine sodium salt) and 3-(diphcnylphosphinyl)aniline hydrochloride (IS) by a simple ion-exchange reaction (Scheme 10.6). The coordination behavior ofthe ion-pair 14 /I S has been tested with various transition metal complexes. Other... 

TPPMS - m-monosulfonated triphenylphosphine. base = aniline Tp hydrotrispyrazolylborates... 

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. 

Much emphasis has been placed in recent times on easily recoverable liquid bi-phasic catalysts, including metal clusters in nonconventional solvents. For instance, aqueous solutions of the complexes [Ru3(CO)12.x(TPPTS)x] (x=l, 2, 3 TPPTS = triphenylphosphine-trisulfonate, P(m-C6H4S03Na)3) catalyze the hydrogenation of simple alkenes (1-octene, cyclohexene, styrene) at 60°C and 60 bar H2 at TOF up to 500 h 1 [24], while [Ru i(CO)C (TPPMS) >,] (TPPMS = triphenylphos-phine-monosulfonate, PPh2(m-C6H4S03Na) is an efficient catalyst precursor for the aqueous hydrogenation of the C=C bond of acrylic acid (TOF 780 h 1 at 40 °C and 3 bar H2) and other activated alkenes [25]. The same catalysts proved to be poorly active in room temperature ionic liquids such as [bmim][BF4] (bmim= Tbutyl-3-methylimidazolium). No details about the active species involved are known at this point. 

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... 

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