Phosphanes sulfonated

Other routes to sulfonated phosphanes are the nucleophilic substitution of phosphides [Eq. (1)], which was first published in 1995 (26), and the reaction of halogenated arenesulfonates with PH derivatives (27) [Eq. (2)]. 

Scheme 2. Examples for polydentate and chiral sulfonated phosphanes.

Complexes of ruthenium, [HRu(CO)Cl(tppms)3] 2H20 and [HRu(CO) Cl(tppts)3], were reported to be catalysts for the same hydrogenation reaction (92). The metal complexes were not pure rather, they were used in the presence of the free sulfonated phosphanes and their respective oxides. 

The telomerization of dienes in a two-phase system was first described in a patent (100). Water was used as the solvent for the catalyst, with sulfonated phosphane ligands providing the water solubility. Water, alcohols, phenols, acids, amines, and acetylacetic add were used as nucleophiles. 

This screening concept was also applied to liquid/liquid systems. As a test reaction, the isomerization of allylic alcohols to carbonyls with water-soluble catalysts in a biphasic heptane/water system was chosen [109,113]. The catalysts (metal precursor, Rh, Ru, Pd, Ni ligands, sulfonated phosphane or disphosphane ligands) were injected the liquid carrier 2 (water). The substrates (different allylic alcohols) were injected into liquid carrier 1 (heptane) ... 

Based on nucleophilic addition, racemic allenyl sulfones were partially resolved by reaction with a deficiency of optically active primary or secondary amines [243]. The reversible nucleophilic addition of tertiary amines or phosphanes to acceptor-substituted allenes can lead to the inversion of the configuration of chiral allenes. For example, an optically active diester 177 with achiral groups R can undergo a racemization (Scheme 7.29). A 4 5 mixture of (M)- and (P)-177 with R = (-)-l-menthyl, obtained through synthesis of the allene from dimenthyl 1,3-acetonedicar-boxylate (cf. Scheme 7.18) [159], furnishes (M)-177 in high diastereomeric purity in 90% yield after repeated crystallization from pentane in the presence of catalytic amounts of triethylamine [158], Another example of a highly elegant epimerization of an optically active allene based on reversible nucleophilic addition was published by Marshall and Liao, who were successful in the transformation 179 — 180 [35], Recently, Lu et al. published a very informative review on the reactions of electron-deficient allenes under phosphane catalysis [244]. 

Phonon broadening, 34 247,253 Phosgene, catalytic synthesis, 28 270-273 Phosphanes aliphatic, 42 493 hydroxyalkyl-substituted, 42 482 quaternary ammonium, 42 492 sugar derivatives, 42 482-483 sulfonated, 42 476-478 Phosphanorbomadienes... 

The direct sulfonation with sulfuric acid discovered by Hanson et al. (18) is more effective. Another method by which the formation of phosphane oxide is strongly inhibited was published in 1995 the use of B(OH)3 in combination with sulfur trioxide hinders the oxidation and offers the possibility to control the number and the position of sulfonate groups (19). 

The introduction of a sulfonate group by reaction with oleum is not limited to arylphosphanes. Tris(co-pbenylalkyl)phosphanes, P[(CH2) (C6H5)]3 (n = 1, 2, 3, and 6), can be sulfonated in the para position and to a lesser extent in the meta position (18). The technique of sulfonating water-insoluble ligand precursors can be applied to bidentate, polydentate, and chiral phosphanes (20-24) the compounds 1-3 are presented in Scheme 2 as examples. 

The latest developments to produce sulfonated, water-soluble phosphanes are characterized by improvements of direct functionalizations to build up tailor-made molecules. 

The catalyst was successfully recycled and reused five times without any loss in activity. It was also demonstrated that (phosphane)AuIcarboxylates and sulfonates are highly active catalysts for hydration of non-activated alkynes. Analogous Ag1 complexes are not active for these reactions due to the fact that the Ag1 cations are much stronger acceptors for their ligands and counterions compared with Au1 cations. 

In the same area, these authors have also investigated the efficiency of various chiral sterically congested phosphane-amide bifunctional organocatalysts with a binaphthyl scaffold in asymmetric aza-Morita-Baylis-Hillman reactions of A -sulfonated imines with activated olefins such as methyl and ethyl vinyl ketones." The corresponding aza-Morita-Baylis-Hillman adducts could be obtained in moderate to excellent yields (37-98%) and moderate to good... 

Herd, O Hessler, A. Langhans, K.P. Stelzer, O. Sheldrick, W.S. Weferling, N. (1994) Water-soluble phosphanes. 2. New method for synthesis of water-soluble secondary and tertiary phosphanes with sulfonated aromatic residues crystal structure of V para-C6H4S03K)3-KC1-0.5H20, J. Organomet. Chem.,415,99-111. 

The rhodium-catalyzed hydroformylation of 1-dodecene was investigated with a series of sulfonated water-soluble phosphane ligands such as Ph2P(CH2)2S (CHjljSOjNa and Ph2P(CH2)2S(CH2)3S03Na at 120 °C and 60bar CO H2 = l l. The ratio of 1 -dodecene/rhodium could be increased up to 10 000. Turnover numbers >50 000 were achieved without any surfactant and TONs were increased up to about 65 000 in the presence of polyoxyethylene-polyoxypropylene-polyoxyethylene tri-block copolymers [99]. 

The potential of alkyl-sulfonated diphosphane ligands associated with methylated a- and P-cyclodextrins during the reaction of rhodium-catalyzed hydroformylation of 1-decene was studied. In all cases, the presence of cydodextrins increased the conversion and the diemoselectivity, whereas the hnear-to-branched ratio of the aldehyde product decreased. The decrease in regiosdectivity was attributed to the formation of low-coordinated phosphane spedes [112]. 

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