Triphenyl phosphite derivatives

This is, as expected, the rarest oxidation state as far as non-organometallic complexes of rhenium are concerned. The dirhenium phosphite complex Re2[P(OMe)3]10 has been prepared12,13 in low yield by several methods, viz. the potassium-potassium iodide reduction of ReOCl3(py)2 or an ReCLj-pyridine complex, followed by treatment with trimethyl phosphite. This yellow complex displays a 31P H) NMR spectrum that appears as a first order AB4 pattern, and is isoelectronic with Re2(CO)l0. It reacts with H2 upon photolysis in THF solution to produce hydridorhenium(III) and other species.13 The related triphenyl phosphite derivative Re2[P(OPh)3]l0 has been described14 as a product of the reaction between ReH3(PPh3)4 and P(OPh)3. 

The aHphatic iodine derivatives are usually prepared by reaction of an alcohol with hydroiodic acid or phosphoms trHodide by reaction of iodine, an alcohol, and red phosphoms addition of iodine monochloride, monobromide, or iodine to an olefin replacement reaction by heating the chlorine or bromine compound with an alkaH iodide ia a suitable solvent and the reaction of triphenyl phosphite with methyl iodide and an alcohol. The aromatic iodine derivatives are prepared by reacting iodine and the aromatic system with oxidising agents such as nitric acid, filming sulfuric acid, or mercuric oxide. 

A series of 1-aminoalkanediphosphonic acids has been reported by the treatment of the N-phenylthiourea derivatives of a>-diethoxyphos-phinoylaldehydes with triphenyl phosphite.343 This constitutes an approach toward the analogues of aspartic and glutamic acid in which both carboxylate sites have been replaced by phosphonic acid functions. A similar approach has also been reported to be of use for the preparation of (diphenyl ester) phosphonate analogues of ornithine, lysine, and homolysine.344345... 

The reaction of singlet oxygen with conjugated double bonds usually is a 1,4-cycloaddition leading to formation of derivatives of the 1,2-diox -ene ring system. This can be achieved either by photooxidation or by reaction in the presence of triphenyl phosphite-ozone adduct (Section Vin.D.2), shown in equations 85 and 86 . ... 

The condensation of an aldehyde, benzyl carbamate, and triphenyl phosphite, first described by Oleksyszyn et al., 25,26 affords a direct route to a-aminoalkylphosphonates 4 that are conveniently protected for subsequent reactions (Scheme 4). Since dealkylation of the quaternary phosphonium intermediate 3 is not possible in this case, formation of the pen-tavalent product 4 presumably involves activation of the solvent and formation of phenyl acetate. This method is useful for the synthesis of aliphatic and aromatic amino acid analogues. However, monomers with more elaborate side chains are often incompatible with the reaction conditions. The free amine can be liberated by treatment with HBr/AcOH or by hydrogenolysis after removal of the phenyl esters. The phosphonate moiety can be manipulated by ready exchange of the phenyl esters in alkaline MeOH and activation as described in Section 10.10.2.1.1. Related condensations with other trivalent phosphite derivatives have been reported. 27-30 ... 

The method employing triphenyl phosphite methiodide, as adapted to carbohydrates,130 has been used for the synthesis of protected 4-deoxy sugars. From methyl 2,3-di-0-methyl-6-0-p-tolylsulfonyl-a-D-glucoside and the corresponding D-galactoside, epimeric 4-iodo derivatives were obtained these were both reduced to methyl 4-deoxy-2,3-di-0-methyl-b-0-p-tolyl-sulfonyl-a-D-zj/Zo-hexoside. 

The first of these methods involves the reaction of triphenyl phosphite methiodide with methyl 3-0-methyl-2-0-p-tolylsulfonyl-a-D-glucopyrano-side, hydrogenation of the resulting 4,6-diiodo derivative, and hydrolysis,186 as adapted to monosaccharides by Kochetkov and coworkers.1,0 In another approach,281 ethyl 2,3-anhydro-4,6-dideoxy-D-nbo-hexopyranoside, obtained from desosamine, was treated with sodium methoxide, to give a mixture of 2- and 3-methyl ethers. After fractionation and separation of side products,288 the 3-methyl ether was hydrolyzed, to give crystalline chalcose. McNally and Overend800 have described another synthesis, starting from methyl 4-deoxy-D-xj/Zo-hexoside.107... 

Cobalt complexes find various applications as additives for polymers. Thus cobalt phthalocyanine acts as a smoke retardant for styrene polymers,31 and the same effect in poly(vinyl chloride) is achieved with Co(acac)2, Co(acac)3, Co203 and CoC03.5 Co(acac)2 in presence of triphenyl phosphite or tri(4-methyl-6- f-butylphenyl) phosphite has been found to act as an antioxidant for polyenes.29 Both cobalt acetate and cobalt naphthenate stabilize polyesters against degradation,73 and the cobalt complex of the benzoic acid derivative (12) (see Section 66.4) acts as an antioxidant for butadiene polymers.46 Stabilization of poly(vinyl chloride)-polybutadiene rubber blends against UV light is provided by cobalt dicyclohexyldithiophosphinate (19).74 Here again, the precise structure does not appear to be known. 

The (PhO)3P/Cl2 reagent, prepared in situ by titrating a solution of triphenyl phosphite with chlorine, was used to convert the phenoxyacetamido cephalosporin (cephalosporin V) derivative 29 into the 7-amino derivative 30 (as an easily filterable hydrochloride) in excellent yield (Equation 3) <2004OL3885>. A 7-formamido cephalosporin was deformylated with concentrated HC1 to yield the corresponding 7-amino compound <2000BMC2317>. 

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. 

Phosphorus in both the 3 and 5 coordination states can be introduced into this class of heterocycle (Scheme 19). The diaminopyrimidine (189 R1 = R2 = H) reacts with triphenyl phosphite to give the phosphorus(III) derivative (95) <79Mi 713-01). By the use of phosphorus pentachloride the dichloro compounds (97) are formed <70K.GS7io>, whilst phenyl phosphonamide produces the derivatives (190) <63CI(L)819>. 

A relatively novel class of derivatives is obtained by the covalent incorporation of organometallic moieties into cellulose. For example, cellulose ferro-cenyl derivatives have been prepared by esterification of cellulose with an intermediate derived from ferrocene carboxylic acid and triphenyl phosphite in the presence of pyridine [84]. An enzymatically cleavable cellulose ester has been developed [85], and prodrugs have been coupled to the hydroxyl or carboxyl functions of C-terminal aromatic amino acids of cellulose peptide derivatives for controlled release applications [86]. 

The tris(tert-butylsulfanyl)cyclopropenylium ion 11 readily reacted with trialkyl phosphites to give the (cycloprop-2-enyl)phosphonate derivatives 12 but not with triphenyl phosphite, even under more forcing conditions. The reaction with hexamethylphosphorous triamide gave the (cycloprop-2-enyl)phosphonium salt 13. Similarly, the tri-tert-butylcyclopropenylium ion 14 reacted with lithium bis(trimethylsilyl)phosphide affording the 3-phosphanylcyclopropene derivative 15 in high yield. 

Benzylic-type sulfonium salts derived from thiophene-2- and 3- and furan-2-methanols, where halides are not stable, have been nsed as snbstrates for Suzuki, Stille and Negishi couplings. The 1-Boc-pyrrole-2-methanol analogne was only snccessful in StiUe couplings. An important feature of this method is that triphenyl phosphite was reqnired as the ligand to overcome the problem of reaction of the usual phosphine ligands with the snlfonium salts. ... 

One might expect that a phosphorus reagent having for R an aryl group activated for bimolecular nucleophilic substitution (68) by electron- withdrawing substituents might participate in a Michaelis-Arbuzov reaction. Kamai and Koshkina (159), who prepared a number of chloro-and nitro-substituted derivatives of triphenyl phosphite, found this to be the case for both ortho and para isomers of tris(monochlorophenyl) phosphite, which reacted with alkyl halides to furnish phosphonates. On the other hand, tris(2,4,6-trichlorophenyl) phosphite and tris(2,4-dichlorophenyl) phosphite (155) gave only complexes with methyl iodide however, lower reaction temperatures were employed. 

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