Phosphorylation phosphites

Phosphorous acid esters from phosphoryl phosphites ... 

A convenient route to steroidal aziridines from the diaxial IN3-olefin adducts, e.g., (99), which undergo elimination with lithium aluminum hydride, was developed by Galle and Hassner. Upon treatment with trialkyl phosphite, these adducts are converted to A-phosphorylated aziridines which are reduced by lithium aluminum hydride to the free steroidal aziridine. 

These phosphorus-containing PAN derivatives are unstable under hydrolytic conditions, and the phosphoryl groups are easily split off under the action of boiling water. If, however, the modified PAN is treated with dimethyl phosphite solution in toluene in the presence of dimethylamine, a modified PAN, stable towards hydrolysis, is obtained. Its composition seems to be the following ... 

The photo-Arbuzov rearrangement of allyl-, benzyl- and naphtylmethyl-phosphites (Scheme 13), first developed by Bentrude et al. [20], found applications in the preparation of phosphonates (70-90%) [38]. Arylphosphonates have been shown to act as protein tyrosine kinase inhibitors [39] or non-hy-drolyzable analogs of phosphorylated tyrosine residues [40]. 

A. Nucleophilic Reactions.—(/) Attack on Saturated Carbon. The Arbusov reaction has been used to prepare organosilicon-substituted phosphonates (1) and phosphorylated ethers (2a) and sulphides (2b). Bromo- and chloro-derivatives of the cyclic phosphite (3) do not react with ethyl halides... 

A -Acyl salts of nitrogen heterocycles phosphorylate in the hetero-ring, rather than at the carbonyl group, to give, for example, (25). The addition of dialkyl phosphites to ynamines has been reported. The products... 

The reaction of dialkyl and trialkyl phosphites with / -quinonedisul-phonimides (65) has evoked considerable interest. Levy and Sprecher isolated the nitrogen phosphorylated product (66) in 80% yield from a reaction with dialkyl phosphite, although other workers claim that attack is at carbon to give (67). 

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... 

The reaction with phosphite esters is known as the Michaelis-Arbuzov reaction and proceeds through an unstable trialkoxyphopsphonium intermediate. The second stage is another example of the great tendency of alkoxyphosphonium ions to react with nucleophiles to break the O—C bond, resulting in formation of a phosphoryl P—O bond. 

The kinetics of deuterium isotope exchange between diphenyl phosphine and t-butylthiol have been studied by H n.m.r. spectroscopy.274 A negative temperature coefficient was observed for the reaction of a perf1uoroalky1 phosphite with a fluorinated aldehyde.275 The kinetics for the reaction of alcohols with phosphoryl trichloride bore strong similarities to those of carboxylic acid derivatives.276 An interesting report desribed the solvolysis of ary 1 hydroxymethyl-phosphonates. It was shown that a phosphoryl group does not prevent carbocation formation on an immediately adjacent carbon atom.277... 

All the experiments are conducted on aldehyde terminal functions. Depending on the solubility of the resulting phosphorylated dendrimers, anchorage of phosphorus moieties has been carried out on generation 1 (6 phosphate or phosphinite groups) and up to generation 5 [(96 aminophosphate (Fig. 6, Scheme 15), amino phosphite or functionalized phosphonate groups)] [17b]. 

Arbusov reaction of thienyl halides with phosphites in the presence of nickel catalyst [41, 42], or palladium catalyzed phosphorylation of thienyl halides [43], and some of them are commercially available (Scheme 22). 2,5-Diphosphorylthiophenes were synthesized by Arbusov reaction of thienyl halides with phosphites in the presence of nickel catalyst [44] or reaction of 2,5-dilithiothiophene with phosphorus halides followed by oxidation [45] (Scheme 23). 

Martynov, I.V., Yu.L. Kruglyak, and N.F. Privezentseva. "Phosphorylated Oximes. I. Reaction of Halodialkyl Phosphites with a-Chlorofluoronitroso Alkanes." Zhurnal Obshchei Khimii 37 (1967) 1125-1130 (In Russian). 

Phosphorylated Oximes. II. Reaction of Halodialkyl Phosphites with a-Chloronitro... 

The addition of anionic forms of trivalent phosphorus reagents (diethyl phosphite or diphenylphosphinite) to quinonemethides bearing two phosphoryl linkages on the exocyclic double bond provides a,a,a-triphosphoryl species (Equation 3.32).451... 

Atherton, F.R., Openshaw, H.T., and Todd, A.R., Phosphorylation. II. Reaction of dialkyl phosphites with polyhalogen compounds in the presence of bases — method for the phosphorylation of amines, /. Chem. Soc., 660, 1945. 

Malenko, D.M., Simurova, N.V., and Sinitsa, A.D., Synthesis of phosphoryl-ated oxiranes from silylated dichloroacetylacetone and triethyl phosphite, Zh. Obshch. Khim., 63, 943, 1993. 

Tyryshkin, N.I. and Fuzhenkova, A.V., Phosphorylation of 2,5-bis(methoxy-carbonyl)acecyclone by trimethyl phosphite, Zh. Obshch. Khim., 62,2485,1992. 

Nitrone reactions with lithiated dialkyl phosphite results in the formation of a-(hydroxyamino)phosphonate, which, depending on the character of the R substituent at a-C lead to a-phosphorylated nitrones (429) or fS-phosphorylated nitroxyl radicals (430) after successive oxidations (Scheme 2.200) (686—689). 

In order to synthesize biologically relevant phosphonylimidazole 73, bromoimidazole 72 was derived from radical-initiated bromination of methyl l-p-methoxybenzyl-2-thiomethyl-5-imidazolylcarboxylate (71) [56]. The thiomethyl group served to block the C(2) position, which would otherwise undergo preferential halogenation under these conditions. As expected, a variety of Arbusov-Michaelis reaction conditions failed even under forcing conditions. On the other hand, Pd-catalyzed phosphorylation of 72 with diethyl phosphite led to methyl-4-diethylphosphonyl-l-p-methoxybenzyl-2-thiomethyl-5-imidazolylcarboxylate (73). After further manipulations, the desired phosphonic acid-linked aminoimidazoles, which resembled intermediates formed during purine biosynthesis, were accessed. 

Scheme 2 shows preparation of the biftinctional fiber. PPPE-c and PPPE-f grafted with CMS and ST were functionalized by the reported method.6 Here, an example of functionalization procedures is described. The precursory fibers (PPPE-f grafted with CMS and ST, 2 g) and triethyl phosphite (60 ml) were taken into a three-necked flask (200 ml) equipped with a Liebig condenser. After the mixture in the flask was heated for 48 h at 100 °C, the resulting phosphorylated PPPE-f was washed with acetone, aceton-water mixture and water, and dried in vacuum oven at 40 °C. In order to introduce sulfonic acid groups, the phosphorylated PPPE-f was treated with a 30 mL of 1,2-dichloroethane solution of chlorosulfonic acid (10 wt %) for 2 h at room temperature. Finally, diethyl phosphonate groups on the fibers were hydrolyzed with 12 M hydrochloric acid under refluxed... 

On pp. 45 and 57 we referred to the action of chlorine1 and of N-chlorosuccinimide2 on dialkyl phosphites producing dialkyl phosphorochloridates. We have made use of the latter in producing a variety of esters of orthophosphoric acid and of phos-phoramidates, and reference has already been made to many such reactions (p. 82). These processes are, in a sense, phosphorylations of the alcohols or of the amines respectively. 

Nucleophilic Reactions.—Attack on Saturated Carbon. Selected examples of the Arbusov reaction include phosphorylation of the chloroacetophenones (1) to give phosphonates, which cyclized to (2) in the presence of acid chlorides,1 formation of the azodiphosphonate (3) from 2,2 -dichloro-2,2 -azopropane,2 3 and the reaction of 2-chloro-3,4-dihydro-3-oxo-2//-l,4-benzothiazine (4) with triethyl phosphite to give the 2-phosphonate (5), which is used as an olefin synthon.8 Bis(trimethylsilyl) trimethylsiloxymethylphosphonite (6) has been synthesized by silylation of hydroxy-methylphosphonous acid, and, as expected, undergoes a normal Arbusov reaction with alkyl halides to give the phosphonates (7).4 This series of reactions, followed by... 

Diethyl phosphate esters of the sterically congested phenols of calixarenes have been prepared in acceptable yields (>55%) and used in the preparation of meta-cyclophanes [8]. The corresponding reaction using diethyl phosphite, with triethylamine in place of the quaternary ammonium catalyst, results in only partial phosphorylation of the hydroxyl groups. 

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