Thiophosphoryl compounds oxidation

DMSO is known to be an oxidant for thiophosphoryl compounds. Oxidation of the acid (90) (and its epimer) with this reagent occurs with about 90% inversion of configuration at phosphorus. Oxidation of OOO-triethyl phos-phorothioate with nitrosonium tetrafluoroborate yields bis(diethoxyphosphinyl) disulphide, whereas electrochemical oxidation at a platinum surface gives unidentified phosphorus-containing products. ... 

S NMR spectra of thiocarbonyl, thiophosphoryl compounds, and of some sulphonium salts have also been published. Machiguchi et al. have reported the 33S NMR spectrum of tropothione41 2, a thiocarbonyl compound, and of its corresponding S-oxide, 3 and sulphenic acid, 4.42... 

Studies of Equilibria, Reactions, and Solvent Effects.—Lanthanide shift reagents have been found to be effective for phosphines and phosphoryl compounds, but not for thiophosphoryl compounds. - In a comparison of various shift reagents, europium nitrate hexadeuterium oxide (26) was found to give large shifts of 8 for phosphates and phosphonates. A contact contribution to the Sp shifts was established. When there are two possible sites for co-ordination, as in the aminophosphine (27), steric effects play an important role. Co-ordination occurs at nitrogen in (27 R = H) but at phosphorus in (27 R = Me). The n.m.r. parameters... 

Mikrfajczyk M, Luczak J, Kielbasinski P, Colonna S (2009) Biocatalytic oxidation of thiophosphoryl compounds a new chemo-enzymatic approach to enantiomeric insecticidal thionophosphates and their oxons. Tetrahedron Asymmetry 20 1948-1951... 

The solid state structure of the thiophosphorylated host depicted in Fig. 3 shows unambiguously the all inward orientation of the four P=S bonds [71]. As in the oxidized parent compound 12c, a solvent molecule (acetonitrile) is entrapped in the cavity of the host, and another one is embedded at the lower rim between the four long alkyl chain substituents. 

R0)2P-S—S—P(0R)2. A number of these products and others from reactions of dithiophosphoric acids with oxidants are listed in Table 2 since they are some of the impurities to be anticipated. Thiophosphoryl (P=S) compounds are rapidly, quantitatively, and stereospecifically converted to phosphoryl (P=0) compounds by organic peroxy acids under mild conditions. The reactions of peroxy acids and dithiophosphoric acids and salts have apparently not been characterized. 

Sulfur sometimes plays a role as propesticide in compounds in which biological activity is enhanced by enzymic oxidation thus, for the insecticide malathion (5) (Figure 2), potency is increased by the in vivo conversion of the thiophosphoryl P=S into the phosphoryl P=0 group in the insect. 

Oxidation of thiophosphoryl and thiocarbonyl compounds (4, 194). Compounds containing group (1) or (2) are oxidized by DMSO containing a catalytic amount of iodine to the oxygen analogs. Oxidation of optically active phosphine... 

Herriott used the phosphorus epimers of 0-(-)-menthyl methylphenylphosphinoth-ioate to demonstrate the almost quantitative stereospecificity in the reaction with mCPBA by contrast, the use of trifluoroperoxyacetic acid was less successful, with a retention to inversion ratio of 21 79. A further feature in favour of mCPBA is the independence of its activity relative to solvent. Other extensive correlations were made by Inch and coworkers during investigations into the stereochemistry of displacement reactions at phosphorus in compounds based on a carbohydrate template 81 by means of structural assignments based on infrared absorption frequencies for the P=0 bond together with P NMR chemical shifts, they showed that mCPBA oxidation of thiophosphoryl or selenophosphoryl bonds (A or B = =S or =Se, B or A = Me or Ph) occurred highly stereoselectively with the formation of the phosphonate ester with retained stereochemistry ... 

The reactions of bis(phosphoryl) disulphides with a variety of tervalent phosphorus acid derivatives or triphenylphosphine have been studied by means of low-temperature n.m.r. Intermediates were detected which indicated initial attack on one sulphur atom followed by substitution reactions at one of the phosphorus atoms, Arbuzov dealkylations, or phosphorane formation. An example is shown for the reaction of tributyl phosphite with bis(diethoxyphosphoryl) disulphide (25). In order to obtain solely thiophosphate products it is necessary to use bis(thiophosphoryl) disulphides, and one such compound (26) has been proposed as a highly effective reagent for the oxidation of oligonucleoside phosphites to phosphorothioates. A comparison of the efficiency of (26) with that of four other sulphurizing agents for use in... 

Some bond dissociation energies corresponding to the dissociation of phosphoryl, thiophosphoryl, and N-alkyl (phosphinimine) compounds are shown in Table 2. In this last case dissociation gives rise to the trivalent PX3 compound and the radical NR. Some of these values have been calculated from the difference between the heats of formation of APX3 and PX3 compounds, whilst others are derived from direct measurements of heats of oxidation. 

Some oxides and sulfides have also been prepared from phosphoryl or thiophosphoryl ehlorides, but very low or no diastereoseleetivity has been found. This class of compounds were also found to suffer the [1,3] P-O... 

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