Phosphines TPPTS

To prepare more hydrophobic starches for specific applications, the partial substitution of starch with acetate, hydroxypropyl, alkylsiliconate or fatty-acid ester groups has been described in the literature. A new route, however, consists of grafting octadienyl chains by butadiene telomerization (Scheme 3.9) [79, 82, 83], The reaction was catalyzed by hydrosoluble palladium-catalytic systems prepared from palladium diacetate and trisodium tris(m-sulfonatophenyl)phosphine (TPPTS). 

Special mention has to be made of the use of surfactants. Aryl halides are insoluble in water but can be solubilized in the aqueous phase with the aid of detergents. A thorough study [24,25] established that the two-phase reaction of 4-iodoanisole with phenylboronic acid (toluene/ethanol/water 1/1/1 v/v/v), catalyzed by [PdCl2 Ph2P(CH2)4S03K 2], was substantially accelerated by various amphiphiles. Under comparable conditions the use of CTAB led to a 99 % yield of 4-methoxybiphenyl, while 92 % and 88 % yields were observed with SDS and n-Bu4NBr, respectively (for the amphiphiles see Scheme 3.11). Similar effects were observed with Pd-complexes of other water-soluble phosphines (TPPTS and TPPMS), too. 

In a 100-mL Schlenk tube equipped with a magnetic stirrer, 1.95 equiv (4.83 g) of the sodium salt of tris(3-sulfonatophenyl)phosphine (TPPTS) dissolved in a minimum amount of water (ca. 5 mL) are added at room temperature to the solution of [NH2Me2] [Rh(CO)2Cl2] prepared as described in Section 21.K. The reaction is fast, with significant CO evolution. After 15 min, an IR spectmm of the solution shows a single vco band at 1982 cm. The yellow product is precipitated by adding 50 mL of cold ethanol, then collected by filtration on a Buchner funnel, washed with 150 mL of ethanol, and dried under vacuum. Yield 3.81 g (71%). 

Likewise, in the case of the oxygenated analogs, the combination of the aqueous medium, the water-soluble phosphine tppts (199), palladium(II) acetate, and cinnamyl acetate plus DBU changed the outcome of the reaction dramatically. Thus, from 214, 219, and 224, only sulfides 218,223 and 226 were formed. The sulfides are the products of kinetic control (see the conversion of 218 into the mixture of N-l, N-3, and N-l/N-3 allylated compounds) they separate from the reaction aqueous medium. And this fact, together with the lower temperature required when working in water/ acetonitrile (17/3), permits isolation of the sulfides instead of the thermodynamically more stable /V-allylated compounds. 

In two recent communications this group has used formaldehyde as the CO source in aqueous media and has introduced chiral ligands in the rhodium complex reaching high yields and enantioselectivities. A hydrophilic phosphine (TPPTS) and a surfactant (SDS) are also added to enable the reaction (Scheme 38) [142,143]. 

An example of a large scale application of this concept is the Ruhrchemie/ Rhone Poulenc process for the hydroformylation of propylene to n-butanal, which employs a water-soluble rhodium(I) complex of trisulfonated triphenyl-phosphine (tppts) as the catalyst [103]. The same complex also functions as the catalyst in the Rhone Poulenc process for the manufacture of the vitamin A intermediate, geranylacetone, via reaction of myrcene with methyl acetoacetate in an aqueous biphasic system (Fig. 1.35) [104]. 

Anionic metal complexes, for example [Rh(CO)2l2], can be exchanged onto the anion-exchange resin Dowex 1-X8. The supported rhodium carbonyl iodide complex functions as an immobilized methanol Carbonylation catalyst. Metal complexes of the water-soluble phosphine TPPTS and its monosulfonated analog have also been exchanged onto anion-exchange resins. The pendant sulfonate groups provide the electrostatic attraction to the support. 

Metal-carbonyl complexes of the sodium salt of trisulfonated triphenyl-phosphine TPPTS (Section III-A) have also been synthesized. The prepar-... 

The Ruhrchemie/Rhone-Poulenc Oxo process (Figure 4.1, Scheme 4.1) was developed for the synthesis of butyraldehyde from propylene and synthesis gas, where the water-soluble tris(m-sulfonated-phenyl)phosphine (TPPTS)-modified rhodium catalyst operates in the aqueous phase [14]. 

IN SITU PREPARATION OF A WATER-SOLUBLE RHODIUM CATALYST FROM [RhCl(COD)]2 AND TRISODIUM SALT OF TRIS(m-SULFONATOPHENYL)PHOSPHINE (tppts)... 

A recent breakthrough has been the use of two-phase technology, commercialized in the Ruhrchemie/Rhone Poulenc process, which uses a new water-soluble rhodium complex with polar SOsNa groups on the phenyl rings of the phosphine (TPPTS) [1]. 

The combination of water and an organic nitrile as the solvent system (aqueous bipha-sic system, ABS) permits one to separate the catalyst in the water solution, coordinated to a water-soluble phosphine, TPPTS, the trisodium salt of trisulfonated triphenylphos-phine.f" The groups of Sinou and Genet have studied this strategyy. " ° " ° Allylic carbonates are quite stable to the potentially hydrolytic conditions since the reactions occur in neutral medium and only traces of base are generated in the catalytic cycle. Organic-aqueous phase palladium catalysis has been reviewed extensively. 

The deprotection of Alloc-protected amines can also be accomplished in aqueous media employing the water-soluble phosphine TPPTS and excess diethylamine as the nucleophilic scavenger.i Secondary amines have also been successfully deprotected with no competing A-allylation using biphasic conditions in conjunction with Pd(OAc)2, TPPTS and excess diethylamine. ... 

Shinokubo et al. reported a Rh-catalyzed [2 + 2 - - 2] cycloaddition of alkynes in an aqueous-organic diphasic system using trisodium tris(m-sulfonatophenyl)phosphine (TPPTS) as a water-soluble ligand [8]. When a triyne with a long tether was used, meffl-cyclophane was obtained in low yield as a minor cycloadduct (Scheme 8.11). 

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