Trialkyl phosphites esters

The bonds in PC13 are reactive toward many compounds that contain OH groups. Consequently, alcohols react with PC13 to produce trialkyl phosphite esters. 

The mechanism for the reactions with phosphorus halides can be illustrated using phosphorus tribromide. Initial reaction between the alcohol and phosphorus tribromide leads to a trialkyl phosphite ester by successive displacements of bromide. The reaction stops at this stage if it is run in the presence of an amine which neutralizes the hydrogen bromide that is formed.9 If the hydrogen bromide is not neutralized the phosphite ester is protonated and each alkyl group is successively converted to the halide by nucleophilic substitution by bromide ion. The driving force for cleavage of the C—O bond is the... 

Phosgene Oxalyl Chloride, and Maleyl Chloride. Phosgene reacts with trialkyl phosphite esters to yield, not the expected acylphosphonate as erroneously reported (148), but instead the phosphorochloridate and carbon monoxide (102,149,243,264). The logical explanation is that... 

Normally, trialkyl phosphite esters are stable in alcoholic or phenolic solutions except for transesterification (134). However, at 210-215°, trimethyl phosphite is isomerized to dimethyl methylphosphonate, and triethyl phosphite is converted to diethyl methylphosphonate by methanol (79). The formation of these substances has been rationalized as proceeding via the intermediate [AIeOP(i Ie)(OR)2]+ OH. 

A variety of S-hydroxyphosphonates (494) have been produced in high yields by ring opening reaction of different types of epoxides (493) with di-or trialkyl phosphite esters catalyzed by Al(OTf)3. The reactions proceeded with complete chemo- and regioselectivities to give the title compounds (Scheme 126). ... 

A general method for conversion of alcohols to chlorides involves reaction with PCI3 or PCI5. Similarly, alcohols and PBrs yield alkyl bromides. These reactions presumably involve initial attack on the phosphorus halides by the alcohol to form a trialkyl phosphite ester. Introduction of the halide then occurs, with inversion of... 

Triethyl phosphite is a colourless mobile liquid, insoluble in water. Trialkyl phosphites are valuable intermediates in the preparation of many organophosphorus compounds they readily form dialkyl esters of alkylphosphonic acids by the Arbusov reaction (p. 311). 

When an alkyl halide is heated with a trialkyl phosphite, an ester of a phos-phonic acid is produced. This is known as the Arbusov Reaction ... 

Other Plastics Uses. The plasticizer range alcohols have a number of other uses in plastics hexanol and 2-ethylhexanol are used as part of the catalyst system in the polymerization of acrylates, ethylene, and propylene (55) the peroxydicarbonate of 2-ethylhexanol is utilized as a polymerization initiator for vinyl chloride various trialkyl phosphites find usage as heat and light stabHizers for plastics organotin derivatives are used as heat stabHizers for PVC octanol improves the compatibHity of calcium carbonate filler in various plastics 2-ethylhexanol is used to make expanded polystyrene beads (56) and acrylate esters serve as pressure sensitive adhesives. 

Trialkyl phosphites participate ia Michaehs-Arbu2ov rearrangement with alkyl haUdes. Such esters can undergo auto-Arbu2ov rearrangement ia the absence of an alkyl haUde. 

The reaction proceeds through an intermediate phosphonium salt which can be isolated in some instances. The Michaehs-Arbusov reaction is especially useful for converting trialkyl phosphites, (RO) P, to alkylphosphonic esters, and to esters of phosphonocarboxyhc acids. 

Dialkyl sulfates aie esters of sulfuric acid, trialkyl phosphites ar e esters of phosphorous acid (H3PO3), and trialkyl phosphates are esters of phosphoric acid (H3PO4). 

Formation of esters of inorganic acids (Section 15.9) Alkyl nitrates, dialkyl sulfates, trialkyl phosphites, and trialkyl phosphates are examples of alkyl esters of inorganic acids. In some cases, these compounds are prepared by the direct reaction of an alcohol and the inorganic acid. 

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

Perkov reaction of a trialkyl phosphite with a-chlorothioacetone leads to the 5-phosphorylated enol derivative (7). Not unexpectedly, the phospho-nate ester (8) is formed as a by-product, and in view of studies on the Perkov... 

Baker has also reported the reaction of butadiene with phenylhydra-zones leading to azoalkenes (example 14, Table IV). This is also a Grig-nard-type reaction which is catalytic. Analogous results were obtained with methylhydrazones (136). A wider scope was recently attained by causing allylic esters to react with phenylhydrazones in the presence of zero-valent nickel complexes having trialkyl phosphites (example 15, Table IV). 

Preparation of trisodium phosphonoformate — Reaction of a chloroformate with a trialkyl phosphite and cleavage of the ester linkages... 

Reaction of a trialkyl phosphite with a 2-halocarboxylate ester... 

Two unusual reactions should be noted here. Although quinones generally react with trialkyl phosphites to generate phosphate esters,... 

Finally, (3-bromoacrylate esters react with trialkyl phosphites to provide the unsaturated phosphonates (Equation 3.24), presumably through an addition-elimination route.392... 

Yoneda, S., Kawase, T., and Yoshida, Z.-i., Synthesis of [l-(alkylthio)]- and (1-mercapto)cycloalkanephosphonic esters by the reactions of cycloalkaneth-iones with trialkyl phosphites, /. Org. Chem., 43, 1980, 1978. 

Trialkyl phosphites undergo reaction with molecular halogen via a mechanism reminiscent of the Michaelis-Arbuzov reaction to form the dialkyl phosphorochloridate in good yield (Equation 4.4).7 With cyclic esters, the halogen performing the displacement reaction at carbon remains attached within the molecule. 

Plumb, J.B., Obrycki, R., and Griffith, C.E., Phosphonic acids and esters. XVI. Formation of dialkyl phenylphosphonates by the photoinitiated phenylation of trialkyl phosphites, ]. Org. Chem., 31, 2455, 1966. 

Wulfman, D.S., van Thinh, N., McDaniel, R.S., Pierce, B.W., Heitsch, C.W., and Jones, M.T., Metal salt-catalyzed carbenoids. IX. Catalysts in trialkyl phosphite-copper(I) complex catalyzed decomposition of diazomalonic esters in cycloalkenes, ]. Chem. Soc., Dalton Trans., 522, 1975. 

Amongst the reported syntheses of phosphonic esters, one of cyclohexylphos-phonic esters depends on treatment of cyclohexanthione with trialkyl phosphites followed by desulphurization of the intermediate esters (47) with Raney nickel.41... 

Although ketones are essentially inert to molecular oxygen, enolates are susceptible to oxidation. The combination of oxygen and a strong base has found some utility in the introduction of an oxygen function at carbanionic sites.200 Hydroperoxides are the initial products of such oxidations, but when DMSO or some other substance capable of reducing the hydroperoxide is present, the corresponding alcohol is isolated. A procedure that has met with considerable success involves oxidation in the presence of a trialkyl phosphite.201 The intermediate hydroperoxide is efficiently reduced by the phospite ester. 

The reaction of trialkyl phosphites with acetylenic esters give different products, depending on the reaction conditions. Thus, the reaction of... 

---