Phosphite diphenyl

Salts of dithiocarbamic acid can be prepared by the addition of primary or secondary amines to carbon disulfide. This reaction is similar to 16-9. Hydrogen sulfide can be eliminated from the product, directly or indirectly, to give isothiocyanates (RNCS). Isothiocyanates can be obtained directly by the reaction of primary amines and CS2 in pyridine in the presence of DCC. ° In the presence of diphenyl phosphite and pyridine, primary amines add to CO2 and to CS2 to give, respectively, symmetrically substituted ureas and thioureas ... 

The value of using the preformed HHT with diphenyl phosphite in this procedure was readily apparent from the nearly quantitative conversion to glyphosate observed from 25. A much lower yield (38%) of glyphosate was obtained after hydrolysis when the same components (ethyl glycinate hydrochloride and formaldehyde) were mixed and heated with neat triphenyl phosphite to give triester 30 (43). 

When excess amounts of the HHT of phenyl glycinate 42 were used with diphenyl phosphite, the preferred product was the novel cyclic derivative 45 (2). Presumably, ring-opening of the HHT produced intermediate 43 first, which lost an equivalent of glycinate formaldimine to give 44. The proximity of the activated phenyl carboxylate ester to the N-H in 44 presumably promoted intramolecular cyclization to 45 with loss of phenol (2). 

An Arbuzov reaction between gem-dibromocyclopropanes yields phosphonate esters (55) accompanied by debrominated compounds successful reaction requires the presence of traces of water (and is thus not the normal Arbuzov reaction) which, by studies with D2O, has been shown to supply the a-proton of (56), Normal Arbuzov reactions, using ethyl diphenyl phosphite, have been used to prepare a phosphonate isostere of B-D-arabinose-1,5-diphosphate. ... 

Methanesulfonates 844, obtained by addition of diphenyl phosphite to aldehydes At1 Cl IO and mesylation of the hydroxyl group of the adducts, react with benzotriazole to give diphenyl a-(benzotriazol-l-yl)benzylphosphonates 845. Lithiation and treatment with aldehydes Ar2CHO converts phosphonates 845 into stilbenes 846, which can eliminate benzotriazole to give diarylacetylenes 847 (Scheme 135) <2002ARK(xiii)17>. 

Terada expanded the phospha-Michael reaction to include diphenyl-phosphites [128]. A novel binaphthol-derived guanidine catalyst promoted the addition in high yields and enantioselectivities (Scheme 73). Functionalizing the external nitrogen with a diphenylmethine moeity enhanced selectivities for a large scope of nitro-olefm derivatives. 

The ornithine related phosphonate (n = 3) can be guanidylated at the 4-amino group by treatment with formamidinesulfonic acid to provide Argp(OPh)2. This method can be used for the synthesis of substrate-related thrombin inhibitors such as Ac-Phe-Pro-Argp(OPh)2. 41 Proline analogues required a special approach and a few synthetic methods are reported since dipeptides of Prop(OPh)2 are excellent inhibitors of dipeptidyl peptidase IV (DPP IV or CD 26), the serine protease involved in immune response. 4 Diphenyl phosphite and dialkyl phosphites react smoothly with 1-pyrrolidine (3,4-dihydro-2//-pyrrole) trimer 20 to give the corresponding pyrrolidine-2-phosphonate 21 (Scheme 14). 42 ... 

The possibility that R-0 fission may occur in advance of attack by halide ion has been demonstrated in the reactions of dineopentyl phenyl phosphite or neopentyl diphenyl phosphite with alkyl halides. In these cases the Michaelis-Arbuzov intermediates cannot be isolated but the neopentyl halides which are formed are contaminated with varying amounts of rearrangement product (t-pentyl halide) (Table IV). These results may explain the formation of mixtures of isomeric halides (9,10,11) in certain applications of Rydon s method for alkyl halide preparation (12). S i fission of the R-0 bond appears to be encouraged by the electron-attracting effect of phenoxy-substituents (Figure 3). 

The phenol which is formed as a by-product in these systems also appears to have a significant effect on the mechanism since it increases the proportion of rearranged products obtained. For example, it was found that the interaction of neopentyl diphenyl phosphite with methyl bromide yielded pentyl bromides containing 4.4% of the tertiary isomer, whereas the percentage rearrangement rose to 50 in the presence of one molecular equivalent of phenol. 

The extremely stable phosphonium salts 66 have been synthesized via the alternate route using diphenyl phosphite 67, which is accessible from diphenylchlorophosphane and hexafiuoroisopropanol, thus proving the last step of the reaction (96). 

The five-membered sugar derivative 9, with an aldehyde group at C-l, undergoes reaction with diphenyl phosphite in the presence of triethylamine to give, after treatment with JV,A -thiocar-bonyldiimidazole, the product 10 as a 9 1 mixture of diastereomers31. 

Use of diphenyl phosphite for etherification is limited to A -3-hydroxysteroids (a homoallylic cation is probably involved in this case). Thus cholesterol is converted into 3/f-phcnoxy-A -cholcstcne in 50% yield by treatment with diphenyl phosphite in the presence of an acid catalyst. 

Peptide synthesis. Japanese chemists have reported a convenient synthesis of peptides by means of diphenyl phosphite and a tertiary amine (pyridine was used) as summarized in the equation. Various peptides were prepared in this way in high yield... 

Diphenylpentadiynone, 248 Diphenylphosphine, 505 Diphenyl phosphite, 210 Diphenylphosphorochloridate, 210 Diphenylphosphoryl azide, 210-211... 

Japanese workers have developed a new synthesis of ureas and thioureas through the reaction of carbon dioxide or carbon disulphide with diphenyl phosphite and primary amines. The reaction is thought to take place via an intermediate (85), followed by elimination to give isocyanate or direct displacement by amine. The principles of this new synthesis have also been applied to the preparation of peptides and amino-acid esters. 

The results of the preparation of polyureas under mild conditions (a pressure of less than 40 atm of carbon dioxide and a temperature around 40 °C) and of poly thioureas (using diphenyl phosphite in pyridine) are compiled in Table 1728). Although the preparation of polyureas from carbon dioxide under drastic conditions (high temperatures and high pressures) or from carbon oxysulfide has been reported, neither preparative method is operative under moderate conditions, nor have the methods for the synthesis of polythioureas from carbon disulfide been described. 

Table 17. Direct polycondensation of carbon dioxide and carbon disulfide with diamines using diphenyl phosphite in pyridine8... 

The unfavorable effects of both elevated temperature and high pressure upon the molecular weight may be caused by a depolymerization reaction or by an intermole-cular or intramolecular exchange reaction between polymers, as described by Eqs. (8) and (9). These side reactions may be promoted by higher reaction temperatures and higher pressures of carbon dioxide, and also in the presence of carbon dioxide and/or diphenyl phosphite. 

Chelex MD Diphenyl isodecyl phosphite DPDP EINECS 247-777-4 Isodecyl alcohol, diphenyl phosphite Isodecyl diphenyl phosphite Mark 135A Phoselere T 26 Phosphorous acid, isodecyl diphenyl ester Weston DPDP, Chelating agent with metal carboxylates as polymer additives, especially for chlorinated polymers such as PVC and chlorinated PE Improves color, heat and light stability. Liquid bp = 190° d = 1,022-1.032 flash point = 154 . Akzo Chemie, Dover. 

Doverphos DPIOP DPIOP EINECS 247-658-7 Isooctyl diphenyl phosphite Phosphorous acid, isooctyl diphenyl ester Weston ODPP. Color stabilizer for ABC, PC stabilizer for PVC antioxidant... 

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