Phosphonothioates

Phosphonothioate Esters of Phenols. Phosphonates with a single P—C bond are highly toxic and persistent iasecticides but have not been used extensively because some compounds produce delayed neuropathy leading to irreversible paralysis ia higher animals, including humans. Such compounds specifically inhibit an enzyme, neurotoxic esterase, that is responsible for the growth and maintenance of long nerve axons (31,32). 

Phosphonothioic acid, mediyl-, 0-ediyl 0-(4-(niediylthio)phenyl) ester 500 500... 

Phosphonothioic acid, metliyl-, S-(2-(bis (1 -metliylethyl)amino)etliyl) 0-ethyl ester 100 100... 

Phosphonothioic dichlondes, general preparation from phosphomc di-chlondes and tetraphosphorus decasulfide, 46, 22... 

Finally, non-racemic phosphorothioic and phosphonothioic acids 98 were obtained via a PTE-catalysed stereoselective hydrolysis of the prochiral substrates 97 (Equation 48). ° The absolute configurations of the thioacids 98 depended on whether native PTE or its mutants were used. 

The first reductive kinetic resolution of racemic sulphoxides was reported by Balenovic and Bregant. They found that L-cysteine reacted with racemic sulphoxides to produce a mixture of L-cystine, sulphide and non-reduced optically active starting sulphoxide (equation 147). Mikojajczyk and Para reported that the reaction of optically active phosphonothioic acid 268 with racemic sulphoxides used in a 1 2 ratio gave the non-reduced optically active sulphoxides, however, with a low optical purity (equation 148). It is interesting to note that a clear relationship was found between the chirality of the reducing P-thioacid 268 and the recovered sulphoxide. Partial asymmetric reduction of racemic sulphoxides also occurs when a complex of LiAlH with chiral alcohols , as well as a mixture of formamidine sulphinic acid with chiral amines, are used as chiral reducing systems. ... 

Thioesters of 3-phosphonothio carboxylic adds can also be used with great success in this process to produce 5-phophono-dihydrothiopyrans in yields over 80% with dr> 80 20. 

Metal-methoxide reactions of phosphates, phosphorothioates, phosphonates and phosphonothioates. The rate constant data for the (La3 + ( OCH3))2 and 9 Zn2 + ( OCH3)-catalyzed methanolysis of the phosphates and phosphorothioates are given in Tables 9 and 10, respectively, while those for the phosphonates (22a-f)17e and phosphonothioates (23a-e)1 s are given in Tables 11 and 12 along with the corresponding methoxide data. The latter two series data are displayed in... 

The (La3+( OCH3))2 and 9 Zn2+( OCH3) promoted methanolyses of the phos-phonates (22)17e and phosphonothioates (23)17g generally follow the same sort of trends as the phosphates and phosphorothioates discussed above so they need not be discussed in great detail here. Analysis of the linear Bronsted plots for the phospho-nates 22 gives the relationships shown in Equations (27)-(29) which shows the common trend that the j8lg observed for the metal-catalyzed reactions are greater than that of the methoxide reactions. Since the Leffler parameter, a, for the La3+-catalyzed... 

Phosphonothioic acid, methyl-, S-(2-bis(l-methylethylamino)ethyl) 0-ethyl ester O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate S-2-Diisopropylaminoethyl O-ethyl methylphosphonothioate S-2((2-Diisopropylamino)ethyl) O-ethyl methylphosphonothiolate O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate O-ethyl S-(2-diisopropylaminoethyl) methylthiolphosphonoate S-(2-diisopropylaminoethyl) o-ethyl methyl phosphonothiolate Ethyl-S-dimethylaminoethyl methylphosphonothiolate VX EA 1701 TX60... 

Fenophos (O-ethyl-S-phenylethyl-phosphorodithioate) insecticide has been determined in soil by gas chromatography. Fenophos is known to degrade to its oxygen analogue (O-ethyl-S-phenylethyl phosphonothioate) in soil but none was found in the soil samples examined [93],... 

Phosphorothioates and phosphonothioates are of particular significance as insecticides. Schematically, it can be stated that these xenobiotics undergo activation by oxidative desulfuration, and detoxification by hydrolytic cleavage. Oxidative desulfuration transforms phosphorothioates and phosphonothioates to the corresponding oxon derivatives (see Chapt. 7 in [59]), which are highly toxic as potent inactivators of acetylcholinesterase [69]. This route of toxification can be competitive with and/or followed by cleavage reactions, which can be either hydrolytic or oxidative. 

Phosphonothioic dichlorides, general preparation from phosphonic di-... 

---