Trialkylphosphites

Displacement of activated chlorine atoms also proceeds with certain types of organic compounds, but only in the presence of Lewis acid catalysts. Particular examples include epoxides, polyhydric alcohols, trialkylphosphites (12), and P-aminocrotonates (13). These additives are commonly used in conjunction with metallic stabilizers to provide complete, high performance, commercial stabilizer packages. 

Trialkyl esters of phosphonic acid exist ia two structurally isomeric forms. The trialkylphosphites, P(OR)2, are isomers of the more stable phosphonates, 0=PR(0R)2, and the former may be rearranged to resemble the latter with catalytic quantities of alkylating agent. The dialkyl alkylphosphonates are used as flame retardants, plasticizers, and iatermediates. The MichaeUs-Arbusov reaction may be used for a variety of compound types, including mono- and diphosphites having aryl as weU as alkyl substituents (22). Triaryl phosphites do not readily undergo the MichaeUs-Arbusov reaction, although there are a few special cases. 

Fig. 6 Alkenes issued from the reduction of oxiranes in the presence of trialkylphosphites...

A study of sequential Arbuzov-type demethylation reactions of the platinum(II)-phosphite complex [Pt P(OMe)3 4]2+, in which the phosphite ligands are converted to phosphonates, has been described.285 Many of the products of the reaction were characterized by NMR spectroscopy and X-ray crystallography.286 The X-ray structures are the first reported for trialkylphosphite complexes of platinum(II). 

The tetrazole-catalysed alcoholysis of simple dialkylphosphoramidates (267) in THE to yield trialkylphosphites (268) occurs via nucleophilic catalysis (Scheme 29). The proposed mechanism sees tetrazole acting first as an acid catalyst to give the protonated intermediate (269), which then reacts with tetrazolide anion to yield the tetrazolylphosphite (270) alcoholysis of the latter (270) then yields the final product, the trialkylphosphite (268). ... 

A recent report describes the synthesis of Te-anisyl phosphorotellurolate esters by the reaction of anisyltellurium trichloride with trialkylphosphites. The intermediacy of the ani-syltellurenyl chloride, formed by the reduction of the trichloride at the expense of the excess of the trialkylphosphonite, rationalizes the result. 

Following the same procedure, phosphoric thiol esters are prepared by the treatment of trialkylphosphites with thiols in the presence of TeCl4 and lutidine. ... 

Azoles containing an acidic NH-group, e.g. 3,5-dimethylpyrazole, react with various alcohols in the presence of a catalytic amount of ruthenium-, rhodium-, and iridium-trialkylphosphite complexes to afford the corresponding A-alkyl derivatives with excellent yields (92CL575). Regioselective A-alkylation was achieved using alkenes and sulfuric acid (89JHC3). 

A kinetic study of the reaction of trialkylphosphites with mucochloric acid has established that this unusual variant of the Arbuzov reaction proceeds with elimination of both alkyl halide and HC1 at the second stage.87... 

When the reaction of 5-phenyl-l,2,4-dithiazole-3-one(thione) 65 (Ar = Ph, Y = 0, S) with trialkylphosphites is carried out under severe conditions (100 °C, 10 h), two different reaction centers in reactant 65 undergo an attack, namely the ring sulfur atom and the exocyclic sulfur or oxygen atom. In the first case, A-phosphorothioates 79 are formed. Bicyclic products 80 are the result of the second reaction pathway (Scheme 13) <1995JRM442, 1996PS557>. 

Formation of P=N-P-Bridges. A simple reliable synthesis of N-phosphorylated phosphazenes which avoid the handling of the dangerous phosphoryl azides consists in a direct reaction of di- and trialkyl-phosphites and carbon tetrachloride with sodium azide in a single step procedure (eq. 11). The phosphoryl azides formed intermediately instantly react with the trialkylphosphites present. Therefore, their... 

Two vanadium(iv) ethylxanthate complexes have been prepared 440 their e.p.r. parameters are practically identical with those of the corresponding diethyldithio-carbamate complexes and on this basis analogous structures were proposed, i.e. a dodecahedral eight-co-ordinate structure with four bidentate ethylxanthate ligands and a distorted tetrahedral structure with four unidentate ligands. Addition of phosphorus(iii) ligands (L) such as trialkylphosphites to solution of the ethyl xanthate... 

Properly protected phosphorochloridates have been employed, and examples include . bis(2,2,2-trichloroethyl) phosphorochloridate96 and dibenzyl phosphorochloridate.97 Phosphoroiodates prepared in situ by the oxidation of the corresponding trialkylphosphites with iodine can also be used.98... 

Although theTeaction of cyclopropenes with phosphines can lead to ring opening 178b), treatment of l,2-dichloro-3,3-difluorocyclopropene with trialkylphosphites leads to moderate yields of the cyclopropanes (271) 190). 

Aus l-Brom-2-phenyl-alkenen lassen sich auch durch Umsetzung mit Kupferhalogenid-Trialkylphosphit-Komplexen 2-Phenyl-ethenphosphonsaure-diester herstel-len396. 

Trialkylphosphite werden mit Benzolsulfensaure-alkylestern mit guten Ausbeuten zu Pentaalkoxy-phosphoranen oxygeniert23-26 ... 

Other nucleophiles such as phosphines and trialkylphosphites undergo nucleophilic addition to bisbenzene ruthenium and osmium dications 235a and 142 to yield the cyclohexadienyl phosphonium adducts 237 and 238. 

A practical advantage of the HWE reaction over the Wittig reaction is that the phosphorus by-product is water soluble and hence is easily removed from the desired product. The starting phosphonates are also cheap and readily prepared by the Arbuzov reaction9 between trialkylphosphites and an organic halide (see Protocol 2). 

Alkyl phosphonates 264 (Z = O, R R = OEt, Table 26), analogously with the preparation of P-Mannich bases, can be obtained from trialkylphosphites as well as fiom... 

When trialkylphosphites are treated with fluoroalkanoyl chlorides, perhalogenated fluoro-alkenes, perfluorinated aromatics, and other fluorinated alkylating substrates, an Arbuzov reaction takes place and alkyl fluorides are formed as byproducts. The method has been used to prepare 6-fluoro-6-deoxy-l,2 3,4-di-f7-isopropylidenegalactose (1). ... 

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