Functional organophosphorus compounds

Synthetic studies for the discovery of effective antidotes for cholinesterase inhibitors are continuing . Various reactivity studies of oximates with different functional organophosphorus compounds, such as phosphinates, phosphonates, phosphates and thiono analogues (shown in Scheme 5), have been reported . ... 

Nucleophilic phosphorus(LII) reagents undergo 1,4-addition to ot,P-unsaturated carbonyl compounds (and other substrates susceptible to conjugate addition) to yield the corresponding y-functionalized organophosphorus compounds (e.g. 63).129 The precise course and outcome of the reaction depends upon the nature of the phosphorus nucleophile. 

One approach to meet these requirements for permanent incorporation is to introduce functionality into the organophosphorus compound. Thus, the additive will be able to react to become bound into the polymer, either in the polymer backbone or as a pendant group on the polymer chain and thereby to become permanently fixed. This paper will illustrate some of the approaches taken at the Dobbs Ferry, New York laboratory to prepare such functional organophosphorus compounds. 

The literature pertaining to the aminophosphonic acids and, to a lesser extent, to the analogous phosphinic acids, is large (in comparison with that of other areas of functionalized organophosphorus compounds), but the area is well served with reviews of various aspects of the subject Those reviews should be consulted for more examples of compounds and reactions than those given here, and also for descriptions from the less accessible Eastern European and Far Eastern literature. 

Indeed, these reactions proceed at 25 °C in ethanol-aqueous media in the absence of transition metal catalysts. The ease with which P-H bonds in primary phosphines can be converted to P-C bonds, as shown in Schemes 9 and 10, demonstrates the importance of primary phosphines in the design and development of novel organophosphorus compounds. In particular, functionalized hydroxymethyl phosphines have become ubiquitous in the development of water-soluble transition metal/organometallic compounds for potential applications in biphasic aqueous-organic catalysis and also in transition metal based pharmaceutical development [53-62]. Extensive investigations on the coordination chemistry of hydroxymethyl phosphines have demonstrated unique stereospe-cific and kinetic propensity of this class of water-soluble phosphines [53-62]. Representative examples outlined in Fig. 4, depict bidentate and multidentate coordination modes and the unique kinetic propensity to stabilize various oxidation states of metal centers, such as Re( V), Rh(III), Pt(II) and Au(I), in aqueous media [53 - 62]. Therefore, the importance of functionalized primary phosphines in the development of multidentate water-soluble phosphines cannot be overemphasized. 

Chiral phosphoryl and sulfinyl groups are known as efficient auxiliaries in asymmetric synthesis. As reported below, their asymmetric induction in the a-posi-tion has been used to prepare chiral non-racemic organophosphorus compounds a-substituted by a sulfur function. Such compounds can also be obtained from their a-hydroxy analogues by OH-4 SR stereoselective transformation. 

The Chemistry of Organophosphorus Compounds is a multi-volume work within the well established series of books covering The Chemistry of Functional Groups. It is proposed to cover the extensive subject matter in four volumes. 

PI Thomas, L. C., The Identification of Functional Groups in Organophosphorus Compounds, Academic London, (1974). 

F. R. Harley (Ed.), The chemistry of organophosphorus compounds phosphine strategy for the synthesis of functionalized phosphonic acids, Heteroatom Chem. 1997, 8, 103-122. 

F. R. Hartley (Ed.), The Chemistry of Organophosphorus Compounds Phosphine Oxides, Sulfides, Selenides, and Tellurides The Chemistry of Functional Groups, Wiley, Chichester, U.K., 1992. 

Maxwell, D.M., Brecht, K., Saxena, A., Feaster, S., Doctor, B.P. (1998). Comparison of cholinesterases and carboxylesterase as bioscavengers for organophosphorus compounds. In Structure and Function of Cholinesterases and Related Proteins (B.P. Doctor et ah, eds), pp. 387-92. Plenum Press, New York. 

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