Triaryl phosphites

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. 

The primary use for 2,4-di-/ f2 -butylphenol is in the production of substituted triaryl phosphites. 2,4-Di-/ f2 -butylphenol reacts with phosphoms trichloride typically using a trialkylamine or quaternary ammonium salt as the catalyst. Hydrogen chloride is formed and either complexed with the amine or Hberated as free hydrogen chloride gas forming the phosphite ester, tris(2,4-di-/ f2 -butylphenyl)phosphite [31570-04-4] (58). The phosphite-based on... 

Phenols give triaryl phosphites P(OAr)3 directly ai " -160 and these react with phosphorous acid to give diaryl phosphonates ... 

Metal deactivator To form inactive protective films on metal surfaces which otherwise might catalyse oxidation and corrosion reactions Trialkyl and triaryl phosphites, organic dihydroxyphosphines, some active sulphur compounds, diamines in lubricating greases, mercaptobenzothiazole and phosphites... 

Rhodium, hydridotetrakis(triaryl phosphite)-, 4, 922 Rhodium, hydridotetrakis(triethyl phosphite)-, 4, 921 Rhodium, hydridotetrakis(trifluorophosphine)-, 4, 921 Rhodium, hydridotetrakis(trimethylphosphine)-, 4, 924 Rhodium, hydridotetrakis(triphenylphosphine)-, 4, 921, 922... 

Conformational populations of cyanomethylphosphine oxides (136) have been estimated from dipole moments and indicate a preference for the tra/15-conformation. The moments of the o-, m- and p-chloro- and tolyl-derivatives of triaryl phosphites (137, Y = ) and triaryl phosphates (137 Y = O) indicate that the oxygen atom in the latter series causes the aryl rings to rotate further away from a position in which their planes all meet along the molecular symmetry axis. Conformational studies have also been carried out on the dioxaphosphorinanes. The moments of the isomeric series (138a) and (138b) were in the ranges 3.7—4.2 and 5.4—5.5 D respectively. ... 

The trinuclear species Ru3(CO)i2 was less active as a catalyst unless triarylphosphines or triaryl phosphites were added, in which case the activity was greater than that of the mononuclear species. The catalytic polynuclear species was probably H4Ru4(CO)8L4. 

Triaryl phosphites, diaryl alkylphosphonites, and aryl dialkylphosphinites... 

Reaction of a triaryl phosphite with an N-acetoxymethyl-carbamate generated in situ... 

Preparation of diphenyl l-(benzylcarbamoyl)-4-(phthalimido)-l-phosphonate — Reaction of a phthalimido-protected aminoaldehyde with a triaryl phosphite in the presence of benzyl carbamate... 

In contrast to the Michaelis-Arbuzov reaction, triaryl phosphites prove to be quite useful for addition to a,(3-unsaturated carbonyl compounds in this type of reaction. A wide variety of unsaturated compounds have been utilized successfully as substrates for such additions, including condensation products of the simple carbonyl compounds with urea,229 thiourea,230-233 N-substituted thioureas,232 234 235 ethyl carbamate,236 2-imidazolidinone,237 2-imidazoli-dinethione,237 and benzyl carbamate.238-240... 

A variety of substrates has been used in this type of conjugate addition reaction with trialkyl phosphites, with assorted proton sources.361 384 Other types of trivalent phosphorus reagents without acidic (or conjugate base of acidic) sites have also been used successfully for this conjugate addition process, including triaryl phosphites (without dealkylation),369 phosphoramidites,385 389 phospho-nites,363 380 390 and phosphinites.360 380... 

Reaction of an aldehyde with a triaryl phosphite in the presence of a thiourea343... 

Albisson DA,Bedford RB, Lawerence SE, Scully PN (1998) Orthopalladated triaryl phosphite complexes as highly active catalysts in biaryl coupling reactions. Chem Commun 2095-2096... 

In the Arbusov reaction using a triaryl phosphite both the stages (a) and (b) (above, p. 95) are slow, and it is possible to isolate the intermediate phosphonium compound.1... 

The 1,3,2-oxazaphosphorines (105) were obtained from triaryl phosphites and the 3-cyano-3-halogenosuccinimides (104).65 Because of their negative 31P chemical... 

Triaryl phosphite-ozone adducts, 706 Tri( -butyl)silyl peroxides, bis(trimethylsilyl) peroxide reactions, 796 Trichloroacetyl chloride, from tetrachloroethene, 731... 

The structures in brackets are phosphoranyl radicals with nine electrons on phosphorus and are considered to be transient intermediates. The radical, R-, presumably represents some initiator fragment, but since the phosphoranyl radical in Reaction 11 is symmetric, R exchanges can (and do) take place. In this regard, triaryl phosphites autoxidize much more slowly, and it has been suggested (3) that here phenoxy radicals are generated via another exchange (Reaction 13) and then terminate chains. 

The same reaction would account for the known efficiency of triaryl phosphites as inhibitors of hydrocarbon oxidation. 

Triaryl phosphites are not effective as catalysts and alkyl isocyanates usually are not cyclized by phosphites at all, although benzyl isocyanates are reported to yield the corresponding uretidinediones with 1,2-dimethylimidazole as a catalyst (75S463). 

H. N. Rydon and B. L. Tonge, The organic chemistry of phosphorus. Part HI. The nature of the compounds of triaryl phosphites and the halogens, J. Chem. Soc. 3043 (1956) and references cited therein. 

Bedford and colleagues found that phosphines, diphosphines, arsines, and bulky triaryl phosphites are convenient ligands [51]. Best results were obtained with... 

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