Phosphites ionic

Olivier-Bourbigou s group, for example, has recently shown that phosphite ligands can be used in Rh-catalyzed hydroformylation in ionic liquids as well as the well loiown phosphine systems [81]. Since phosphite ligands are usually unstable in aqueous media, this adds (apart from the much better solubility of higher olefins in... 

Nevertheless, the application of ionic liquids in the liquid-liquid, biphasic Rh-catalysed hydroformylation offers technically interesting advantages vs. the traditional aqueous biphasic catalysis e.g. much higher solubility for longer chain olefins and the compatibility of the ionic liquid with phosphite ligands [51]. 

The X—O distances in both the nitrate and phosphite sets (Tables 4-8) are on the long side compared to the other X—O bonds reviewed here. The differences are smallest for X = C in the nitrate. The X... Op interaction should tend to lengthen X—O. The C—O(N) bond should be better described than C—O(P) because of the latter s higher O—P ionic character. For the same reason, the other X—O(P) bonds should be shorter in the phosphite compounds compared to the nitrates. These expectations are realized in the calculated relative X—O bond lengths (Tables 4-9) except for the lead compounds. 

A cation arriving with a nncleophilic anion is another important factor. The nucleophile can attack the substrate in the form of a free ion or an ionic pair. As a rule, lithium salts are less reactive than sodium and potassium salts. Russell and Mndryk (1982) reported several examples of this. The sodium salt of ethyl acetylacetate reacts with 2-nitro-2-chloropropane in DMF yielding ethyl 2-(wo-propylidene) acetylacetate. Under the same conditions, the lithium salt does not react at all. Potassium diethyl phosphite interacts with l-methyl-l-nitro-l-(4-toluylsulfonyl)propane in THF and gives diethyl 1-methyl-l-nitro-l-phosphite. The lithinm salt of the same reactant does not react with the same substrate in the same solvent. 

A few years ago, a new class of ligands namely the sulfonated phosphites (for examples see Table 7, 132, 133) was described.283 287 They show remarkable stabilities in water compared to conventional phosphites such as P(OPh)3 and rhodium catalysts modified with 132 exhibited much higher catalytic activities in the hydroformylation of 1-tetradecene than conventional Rh/P(OPh)3 or Ph/PPh3 catalysts even at lower reaction temperatures.285,286 Sulfonated phosphite ligands may play a role in the emerging field of biphasic catalysis in ionic liquids15 22 or in combination with membrane separation of the metal complexes of these bulky ligands. 

T0 prepare models of TA, the corresponding cyclic alkylene phosphoric acids cannot be directly polymerized because the presence of acidic protons of the phosphate group makes the ionic polymerization impossible. Thus, cyclic phosphorus compounds with blocked third functions have to be used. These are phosphates., phosphoramidates and phosphites. After polymerization the obtained polymer is converted by deblocking into the polyalkylene phosphate, e.g. polysalt or polyacid form. 

Aminoalkyl and Related Acids. - Further development of the classical three component approach to aminoalkylphosphonates (the Kabachnik-Fields reaction) has been reported. The reaction of aldehydes, hydroxylamines and dimethyltrimethylsilyl phosphite using lithium perchlorate/diethyl ether as a catalyst gives N-trimethylsilyloxy-a-aminophosphonate derivatives. The catalytic activities of various lanthanide triflates as well as indium trichloride have been examined for the Kabachnik-Fields type reactions of aldehydes, amines and the phosphorus nucleophiles HP(0)(0Et)2 and P(OEt)3 in ionic liquids. TaCb-Si02 has been utilized as an efficient Lewis acid catalyst for the coupling of carbonyl compounds, aromatic amines and diethyl phosphite to produce a-... 

Besides the common organic solvents used for glycosylations, syntheses of glycosides from glycosyl phosphites in ionic liquids were recently reported [463]. Glycosyl phosphites are frequently used for sialylations [451,454] and a typical example is shown in Scheme 4.44. As illustrated, reaction of the (3-neuraminyl phosphite 205 with the lactose diol 206 afforded the 3-(9-neuraminyllactose derivative 207 in a 55% yield [460]. 

In some cases it is desirable and necessary to use P compounds with low basicity such as phosphites. In order to prepare ionic phosphites of the structure... 

Ionic phosphites (triisooctylamine salts of p-sulfonated phosphorous acid triphenyl ester (TPPpS-TIOA salt) were investigated by Fell and Papadogianakis [14]. Table 3 shows a direct comparison with TPP and acetone as solvent in the hydroformylation of n-l-tetradecene. A significantly better ratio of linear/... 

Table 3. Ligand testing by hydroformylation ionic phosphites (direct comparison with triphenylphosphine).

Alkylphenols (APs), particularly nonylphenols (NPs) and to a lesser extent octylphenols (OPs), are extensively used for the production of alkylphenol polyethoxylates (NPEOs), a class of non-ionic surfactants that has been largely employed for more than 40 years in textile and paper processing and in the manufacture of paints, coatings, pesticides, industrial detergents, cosmetics and spermicidal preparations, as well as various cleaning products. NPs are also used in the manufacturing processes of many plastics and as monomers in the production of phenol/formaldehyde resins. Smaller quantities of NPs are employed in the production of tri(4-nonylphenyl) phosphite as an anti-oxidant for rubber and in the manufacture of lubricating oil additives. 

Whether or not the 4.38 and 6.38 peaks contain phosphorus has not yet been determined. It is believed that they do. However, they may simply be different ionic species of the phosphite ion and as such have different retention times in the IC. 

The reaction can be conducted under thermal conditions (reflux), radical conditions (the presence of traces of benzoyl peroxide induces a fourfold increase in the thermal reaction rate and a slightly better yield), or photochemical conditions (where the reaction proceeds under UV irradiation at room temperature to give the same yield as above no reaction is observed in the dark at room temperature).° ° The mechanism of the reaction has been studied extensively, °° ° °°° °° and it has been concluded that the thermal reaction of triethyl phosphite with CCI4 involves an SnCP substitution. In the presence of UV light or free-radical chain initiators, the radical mechanism generally dominates. The ability of the trichloromethyl radical to initiate a radical chain reaction depends on the relative concentrations of the reagents. The final product mixture is the same as in the ionic casc.°°°... 

Bakkas, S., Julliard, M., and Chanon. M.. Reactivity of triethyl phosphite with tetrachloromethane. Electron transfer versus ionic substitution on "positive" halogen. Tetrahedron, 43, 501, 1987. 

Yavari I, Kowsari E (2007) Ionic liquids as novel and recyclable reaction media for N-alkylation of amino-9,10-anthraquinones by tiialkyl phosphites. Tetrahedron Lett 48 3753-3756... 

The used acid-ionic liquid was recovered and its reusability investigated. It was dried following the same procedure employed when first prepared and then used for the glycosylation of cyclohexylmethanol with the glucosyl phosphite (Fig. 3.2). The recovered acid-ionic liquid could be reused at least five times without any loss in efficiency or need for addition of any further protic acid. 

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