Phosphonates mercapto

Hydration Resistance. Visual examination of a series of Inhibitor-treated FPL-prepared 7075-T6 A1 coupons exposed to high humidity conditions for specified time Intervals Indicated good short-term hydration resistance for several phosphonate and silane compounds (no visible discoloration) The most effective silane compound tested contained the mercapto (-SH) functional group. 

A mechanism, via a 6-hydroxy phosphorothiolate 8-mercapto-phosphate rearrangement, will be shown, and these new synthons will be compared with the phosphonate analogs (Wittig -Horner reagent). 

Intramolecular Wittig-Horner reaction of the compounds 399, which are prepared by the condensation of 2-mercapto-2-arylethanols with a vinyl phosphonate followed by oxidation, gives dihydrothiophenes 400 <1996JHC687>. 

The first asymmetric synthesis of an a-mercapto y-unsaturated phosphonate (203) using the readily available chiral dimenthylphosphonyl ester group and a carbanionic [2,3] sigmatropic rearrangement was achieved. Absolute configuration of the newly formed chiral centre of nonracemic thiol (203) was determined. 

Dialkyl 1,1-dialkoxymethylphosphonates can be condensed with amino-, hydroxy-, or mercapto-1,2-disubstituted benzene derivatives to produce a series of benzoheterocyclic phosphonates. The reactions are carried out under drastic conditions that involve heating a mixture of equimolecular amounts of the reactants at 180°C for several hours in a stream of nitrogen. Under these conditions, the reactions of the phosphonylated acetals go exclusively with cleavage of the C-O-C link in the acetal group. The yields of benzoxazole and benzothiazole derivatives are acceptable (68% and 30%), " but 2-benzimidazolylphosphonate is obtained in only 8% yield (Scheme 5.73). All these syntheses of phosphonylated azoles go through intermediates azolines. 

Hydroxy-l,2,4-thiadiazoles readily form esters with phosphoric acid and its various analogs. Because of the pesticidal properties of these organo-phosphorus compounds, and their reported relatively low toxicity to warmblooded animals, a large volume of preparative work has been undertaken. The patent literature exemplifies almost the full range of possible phosphoric and phosphonic acid derivatives, and their thio analogs. For their production, a hydroxy-1,2,4-thiadiazole is condensed with the phosphoro- or phosphono-chloridic ester (426 or 429), in the presence of a base.332-336 Alternatively, a halogeno-1,2,4-thiadiazole is allowed to react with the appropriate free acid (424 or 427).337-341 The use of mercapto-l,2,4-thiadiazoles, or of the... 

The synthesis of functionalized phosphinic and phosphonic acids and their derivatives. Part A halo, hydroxy, epoxy, mercapto, carboxy and oxo functionalized acids... 

The novel stabilized ylides 378 are obtainable from trialkyl phosphites and dialkoxy-phosphinyldithioformic esters, and on acidolysis yield (alkylthiomethylene)bisphosphon-ic esters. Trialkyl phosphites are also reactive towards cycloalkanethiones, when the products are the (l-mercapto-l-cycloalkyl)phosphonic diesters 379 and their thio ethers 380 ... 

Sulfur-to-carbon migration of a phosphorus substituent has been reported <94TL3083>. 0,0-Diisopropyl-5-(2-thienyl)thiophosphate (548) obtained by phosphorylation of thiophene-2-thiolate was treated with LDA in THF. This induced the rearrangement, leading to diisopropyl(2-mercapto-3-thienyl)phosphonate (549) in 21% yield (Scheme 114b). 0,0-Diisopropyl-S-(3-thienyl)thiophos-phate (5 ) was prepared from lithium thiophene-3-thiolate and diisopropyl chlorophosphate. Similar rearrangement of this gave diisopropyl(3-mercapto-2-thienyl)phosphonate (551) in 47% yield. 

A variety of ester groups have been explored, some of which were discussed in Chapter 4 in connection with organosols. There are many types of SiOR groups, such as where R is nitroalkyl, chioroalkyl, or alkoxyalkyl (508) R contains an acidic substituent such as mercapto, phenolic, sulfonic, phosphonic, or carbamic (509) R contains fluorocarbon groups, for example, OCHi(CF,) X, where X - H or F and n 1-17 (510) ORN and ORS, where N and S are in the form of onium ions... 

Organic anionic. Sodium sulfonates, phosphonates, or mercapto-benzotriazole (MET) are used commonly in cooling waters and antifreeze solutions. 

Sinha, N D and Cook, R. M (1988) The preparation and application of functionalized synthetic oligonucleotides III. Use of H-phosphonate derivatives of protected amino-hexanol and mercapto-propanol or -hexanol. Nucl Acids Res 16, 2659-2669... 

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