Phosphites secondary

A number of additions of secondary phosphites to Schiff bases have... 

The reactions of dimethyl phenylphosphonite with acid chlorides, a-halogeno-ketones, and iV-(bromomethyl)phthalimide have been used to prepare acyl phos-phinates, /3-keto-alkylphosphinates, and phthalimidomethylphosphinates as intermediates in the synthesis of a-diazophosphinic esters.39 a-Amino-phosphonates have also been prepared by the addition of secondary phosphites to nitriles40 and to isocyanides.41... 

An interesting series of reactions were carried out starting from bis (cyclopentadienyl)nickel and secondary phosphite esters (Scheme 24).1713 Finally, the mixed-ligand complex [Pt (MeO)2PO 2diphos] can act by itself as a ligand towards nickel perchlorate giving the mixed metal oligomer (225).1714... 

Deprotonated secondary phosphites [(RO)2PO] may act as ambidentate ligands (22) and (23). Examples of both bonding modes are known. The IR spectrum of silver diethyl phosphite (Nujol mull) was found to bear a striking resemblance to that of triethyl phosphite and showed no bands attributable to a P—H or P=0 group.197 By way of contrast, a 31P NMR spectrum of AgPfO)(OEt)2 in diethylamine gave a single resonance at 104.2 p.p.m.198 It was claimed that... 

E. Blanc calculated for the ionization of constants of phosphorous acid Ki=0 05, and isT2—2 4 XlO-5. I. M. Kolthoff found that the first ionization constant Ky increases from 0 016 in 0 001 Jkf-soln. to 0 062 in O lJf-soln. and the second ionization constant K2, calculated from the H -ion cone, of mixtures of a secondary phosphite with hydrochloric acid is O O07 at 18°. The first stage of phosphorous acid titration may be conducted with methyl-orange as indicator using a comparison soln. with ps—Z 85. A sharp end-point for the second stage is obtained with thymolphthalein as indicator. For the anodic oxidation of the phosphites, vide infra, perphosphates. P. Pascal studied the magnetic properties. 

Rubidium phosphates.—The three phosphates are prepared by the interaction of phosphoric acid and rubidium hydroxide or carbonate in appropriate proportions.13 The primary phosphate, RbH2P04, is acidic in aqueous solution the other two are alkaline. When heated at 244° C. the primary phosphate loses water, yielding the acid pyrophosphate, RbaH2P207.14 The secondary phosphite forms a monohydrate,... 

Attack on Unsaturated Carbon. Numerous reports of addition of tertiary phosphites, secondary phosphites, and silyl phosphites to activated olefins have appeared. The addition of secondary phosphites to acryloyl chloride in the presence of trimethylsilyl azide provides a route to 2-isocyanato-ethylphosphonates (13). ... 

As with secondary phosphites, tertiary phosphites add to ethyl thio-acetylene to give the /S-ethylthioalkenylphosphonate (26) rather than the a-analogue. ... 

Miscellaneous Reactions.—-Mixed alkylalkoxydiphosphines (103) have been prepared from secondary phosphites and chlorophosphines under basic conditions the alternative reaction between secondary phosphine and chloro-phosphite gave much lower yields. Surprisingly, oxidation of (103) with... 

Mixtures of cis- and /ra/w-enaminephosphonates were obtained from the reaction of secondary phosphites with ynamines, the stereochemistry being inferred from n.m.r. data in each case. 

Secondary phosphites and thiophosphites react with silylketens to give vinylphosphonates (58), presumably through rearrangement of (59). The reactions of keten dimers with tervalent phosphorus compounds are much more complicated and have been the subject of extensive study by Bentrude... 

As shown in Table 5.35, blends of immiscible polyesters may be compatibilized through copolymer formation mediated by addition of a phosphite condensing agent. Block copolymer results when the phosphite-activated end-group of one PEST reacts with a nucleophilic end-group of another PEST. The reaction takes place at the phase interface. A secondary phosphite is a byproduct. The relative proportions of copolymer vs. simple chain-extended PEST may depend upon the relative solubihty of condensing agent in each of the immiscible polymer phases. 

Base-catalysed additions of secondary phosphites to isothiocyanates to give thiocarbamoylphosphonates (26) have been re-investigated and the synthetic procedures improved. Two convenient routes to the proline analogue, pyrroli-dine-2-phosphonic acid, have been described (Scheme 3). ... 

The reaction of A -methyl benzaldehyde imine with dichloroethoxyphosphine gives (27) with 2-chloro-l,3,2-dioxaphospholan the product is (28). Acid-catalysed additions of secondary phosphites to glyoxal give the mono- (29) or di-phosphonates (30) which are useful synthons and complexing agents." Basic alumina is an alternative to KF or CsF as catalyst for the preparation of 1-hydroxyalkanephosphonates from carbonyl compounds and secondary phosphites in the absence of solvent. 

The reactivities of some new phosphorylating agents based on 2-oxo-l,3-oxazolidine have been discussed in terms of electron delocalizations. The chemistry of phosphorylated benzimidazolides has been discussed (67 refs.). Noteworthy is the displacement of a nitro group, with resultant C-phosphoryla-tion, when 5(6)-nitrobenzimidazole is treated with secondary phosphite anions. ... 

Primary phenohcs (free-radical scavengers) or secondary phosphite (hydroperoxide decomposer) may be used as heat stabilizers for WPC, while light stabilizers commonly used in WPC include UV absorbers (e.g., benzotriazole or benzophenone), radical scavengers or hydroperoxide decomposers, and hindered amine light stabilizers (HALS). 

E.E. Nifantev, Secondary phosphites and related compounds, Russ. Chem. Revs., 47, 835, 1978. 

D.M. Roundhill, Metal complexes of phosphinites and secondary phosphites. Coord. Chem. Revs., 21, 263, 1978. 

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