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Functionalizations tris phosphite

N-FUNCTIONS Triethyl phosphite. N-OXIDES Iron pentacarbonyl. PHENOLS Phenyl isocyanide. SULFOXIDES Dichloroborane. DESULFURIZATION n-Butyllithium. Hexaphosphorous triamide. Tris-... [Pg.583]

Phosphites Tris-(p-nonylphenyl) phosphite (X) No Widely used in conjunction with conventional stabilisers (q.v.) in PVC. Some types appear to be useful heat and light stabilisers in polyolefins. Function primarily as peroxide decomposers rather than chain-breaking antioxidants. [Pg.137]

In addition to stabilisers, antioxidants and ultra-violent absorbers may also be added to PVC compounds. Amongst antioxidants, trisnonyl phenyl phosphite, mentioned previously, is interesting in that it appears to have additional functions such as a solubiliser or chelator for PVC insoluble metal chlorides formed by reaction of PVC degradation products with metal stabilisers. Since oxidation is both a degradation reaction in its own right and may also accelerate the rate of dehydrochlorination, the use of antioxidants can be beneficial. In addition to the phenyl phosphites, hindered phenols such as octadecyl 3-(3,5-di-tcrt-butyl-4-hydroxyphenyI)propionate and 2,4,6-tris (2,5-di-rcrt-butyl-4-hydroxybenzyl)-1,3,5-trimethylbenzene may be used. [Pg.330]

An interesting variation of this reaction that made use of a three-component, one-pot solventless procedure with the corresponding trialkyl phosphites gave dramatically improved yields of many heterosubstituted glyphosate phosphonate diesters (37). When exactly one equivalent of water, 25, and tris-p-chloroethyl phosphite were mixed and heated under neat conditions for a few hours, nearly quantitative yields of displaced p-chloroethanol and the desired triester product 27 were obtained. If desired, the displaced alcohol was first removed by vacuum distillation, or the mixture could be hydrolyzed directly to GLYH3. Various oxygen, sulfur, nitrogen, cyano, and carboxylate functionalities were similarly accommodated in the trialkyl phosphite. [Pg.23]

Such condensation reactions are also promoted by certain trTvalent phosphorus compounds, e.g. triphenyl phosphite (2) or diphenyl ethylphosphonite (3), or to a lesser extent by pFosphonate esters, e.g. diphenyl n-butylphosphonate (3). "Bates reagent," p-oxobi s[tri s(cTi methyl ami no)phosphoni urn] bi s-tetra-f1uoroborate (2) may also be used to activate the carboxyl function towards amide bond formation during peptide synthesis (4) and to bring about the Beckmann rearrangement of ketoximes (F). [Pg.41]

Therefore, additional heat aging tests were conducted to investigate the possibility that hydroquinone-derived phenolic groups might function differently from the monohydric phenols and somehow contribute to the high activity of the phenolic-phosphite systems. Two substituted hydro-quinones, two polymeric phenolic phosphites based on those hydro-quinones, and combinations of the hydroquinones with triphenyl phosphite and tris(nonylphenyl) phosphite were evaluated in the oven-aging test again 0.4% DLTDP was included in the formulations. [Pg.231]

The success of cycloisomerization reactions of this type is critically dependent on factors that influence the conformational mobility of the side chain bearing the alkene moiety. Additionally, functional groups which are able to serve as ligands at palladium may also be of importance. As an example, neither the (E)- nor the (Z)-crotonate derivative ( -IS or (Z)-13 gives rise to the formation of bicyclic products on treatment with bis(dibenzylideneacetone)palladium/tri-isopropyl phosphite. Instead, the corresponding isomeric substituted butadienes, methyl (2E or 2Z,6 )-7,8-dimethylnona-2,6,8-trienoate (14) and methyl (2E or 2Z)-8-methyl-7-methyl-enenona-2,8-dienoate (15), are formed. [Pg.2280]

Lewis acid catalyzed versions of [4 4- 2] cycloadditions are restricted to functionalized dieno-philes. Nonfunetionalized alkenes and alkynes cannot be activated with Lewis acids and in thermal [4 + 2] cycloadditions these suhstrates usually show low reactivity. It has been reported that intcrmolecular cycloaddition of unactivated alkynes to dienes can be accelerated with low-va-lent titanium, iron or rhodium catalysts via metal-mediated - -complex formation and subsequent reductive elimination39 44. Usually, however, low product selectivities are observed due to side reactions, such as aromatization, isomerization or oligomerization. More effective are nickel-catalyzed intramolecular [4 4- 2]-dienyne cycloadditions which were developed for the synthesis of polycycles containing 1.4-cyclohexadienes45. Thus, treatment of dienyne 1, derived from sorbic acid, with 10mol% of Ni(cod)2 and 30 mol % of tris(o-biphenyl) phosphite in tetrahydrofuran at room temperature affords bicyclic 1,4-dienes 2, via intramolecular [4 + 2] cycloaddition, with excellent yield and moderate to complete diastereocontrol by substituents attached to the substrate. The reaction is sensitive towards variation in the catalyst and the ligand. [Pg.470]

This chapter will be limited to the preparation and properties of compounds (2) with one or two P—C bonds, since only these compounds contain functional groups of phosphorus in the sense of the Patai series. Thus, important classes of tervalent phosphorus acid derivatives with three electronegative groups, e.g. phosphites (3), tris(dialkylamino)phos-phines (4) and phosphoramidites (5), will only be included for illustration of a reaction or property which is common to tervalent phosphorus acid derivatives but has not been sufficiently studied for compounds with a P—C bond. The chapter will cover the highly reactive, dicoordinated derivatives 6, but not diphosphines 1 (X = PR2) or diphosphenes 6 (X = PR). [Pg.4]

The stabilizers are used to perform specific functions. Thus, there are antioxidants, viz. sterically hindered phenols [e.g., pentaerythritol ester] and/or sterically hindered amines (hydro)-peroxide decomposers, viz. phosphite [e.g., tris(2,4-di-tert-butyl phenyl)-phosphite] radical scavengers such as thio-derivatives heat stabilizers [e.g., calcium-zinc type for PVCj light stabilizers and UV blockers [e.g. aluminum flakes or carbon black] for outdoor storage and applications, etc. [Pg.337]

The large solubility (xhq = 2.35 at 10 C) of HCl in tri-n-butyl phosphate is in accord with its description as a strongly basic solvent [Tuck and Diamond (1958) ]. Trialkyl phosphites of ordinary reactivity, e.g., (n-BuO)3P, quickly react at room temperature with HCl to give the dialkyl hydrogen phosphite and alkyl chloride. This reaction does not occur with triphenyl phosphite (xhci = 0.69 at 10°C) and has a low probability of occurrence for tris(trichloroethyl) phosphite (xna = 0.46) at 10 C. The Xhci value for phenol is 0.09 and that for CI3CCH2OH is 0.087 at 10°C it therefore appears that the lone pair of electrons on phosphorus in these phosphites have electron-donor function, and indeed the postulated mechanism for the quick reaction between the n-butyl phosphite and hydrogen chloride is based on this effect. The Xhci value for dialkyl hydrogen phosphites of ordinary reactivity is about 2 at 10°C. [Pg.145]


See other pages where Functionalizations tris phosphite is mentioned: [Pg.247]    [Pg.391]    [Pg.309]    [Pg.183]    [Pg.2522]    [Pg.204]    [Pg.218]    [Pg.223]    [Pg.505]    [Pg.213]    [Pg.215]    [Pg.411]    [Pg.726]    [Pg.15]    [Pg.2521]    [Pg.226]    [Pg.351]    [Pg.25]    [Pg.133]    [Pg.4606]    [Pg.24]    [Pg.141]    [Pg.280]    [Pg.693]    [Pg.199]    [Pg.125]    [Pg.126]    [Pg.285]    [Pg.321]    [Pg.332]    [Pg.377]    [Pg.2]    [Pg.88]    [Pg.13]   
See also in sourсe #XX -- [ Pg.709 ]




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