Phosphines, phosphonates and

The nucleophile assisted ring-opening reactions of phosphonate bearing phthahmide 13 has been utihzed in the synthesis of mixed primary phosphine-phosphonate and aromatic amide functionahzed primary bisphosphines as out-hned in Scheme 6 [50],... 

In spite of its simplicity, the British system was not found to be universally acceptable. Workers in the field everywhere agreed to the acceptance of phosphonic, phosphinic, phosphonous and phosphinous acids and to derivatives of these provided a P—C link was present, e.g. 

The same group studied the lithium cation basicities of a series of compounds of the general formula R R R PO, i.e. phosphine oxides, phosphinates, phosphonates and phosphates, by using Fourier Transform Ion Cyclotron Resonance (FTTCR) mass spectrometry. A summary of their results is shown in Figure 4. The effect of methyl substitution on LCA as well as the correlation between LCA and PA was also investigated by Taft, Yanez and coworkers on a series of methyldiazoles with an FTICR mass spectrometer. They showed that methyl substituent effects on Li binding energies are practically additive. 

In addition to phosphonium salts, which are widely used for the activation of urethane-protected amino acids in peptide synthesis (see Section 3.7), other organophosphorus reagents derived from phosphinic, phosphonic, and phosphoric adds have proved to be efficient coupling reagents. 

Razumov, A.L, Liorber, B.G., Khammatova, Z.K., Sokolov, M.P., Zykova, TV, and Alparova, M.V., Phosphonous, phosphinous, phosphonic and phosphinic compounds. Part 98. Phosphorylated P-nitro alcohols, Zh. Obshch. Khim., 47, 567, 1977 J. Gen. Chem. USSR (Engl. Transl.), 47, 519, 1977. Kroona, H.B., Peterson, N.L., Koerner, J.E, and Johnson, R.L., Synthesis of the 2-amino-4-phospho-nobutanoic acid analogues ( )- and (Z)-2-amino-2,3-melhano-4-phosph()nobiilanoic acid and their evaluation as inhibitors of hippocampal excitatory neurotransmission, J. Med. Chem., 34, 1692, 1991. Toshima, K., Jyojima, T, Yamaguchi, H., Noguchi, Y, Yoshida, T, Murase, H., Nakata, M., and Matsumura, S., Total synthesis of bafilomycin A, J. Org. Chem., 62, 3271, 1997. 

The orders of nucleophilic reactivity for alkylation and acylation were found to be quite different (13, 14) and in subsequent work (15) this finding was related to the extent of bond formation in the transition state as given empirically by the Brpnsted coefficient, (3. Previously, this difference was used to predict the position of bond fission in the alkaline hydrolysis of phosphinate, phosphonate, and phosphate esters (12). Jencks and Carriuolo (16) came to similar conclusions around the same time in outstanding work on the acylation of p-nitrophenyl acetate. 

The enantioselective reactions of carbanions a to phosphorus, such as a-lithiat-ed carbanions of activated phosphines, phosphonates, and phosphine oxides. 

The values of monomeric oxo acids of phosphorus on Sephadex G-25 were almost independent of the pH of the eluent, while on more tightly crosslinked gels, i.e., Sephadex G-10 and G-15, the characteristic pH profiles of the values of the oxo acids were observed, which were similar to the pH titration curves of the corresponding oxo acids [ref. 57, 97]. Satisfactory separations of phosphinate, phosphonate and orthophosphate were effected by using the eluents of appropriate pH values [ref. 97]. 

With an excess of HCl, phosphinates, phosphonates, and phosphates are dissolved or transposed without reduction of the phosphorus. 

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