Dinitrophenyl methyl phosphate, nucleophilic

P-O bond fission is the usual mode of attack by nucleophiles on phosphodiesters, although there are exceptions. The labile diester methyl-2,4-dinitrophenyl phosphate shows significant amounts of attack at aromatic carbon (nucleophilic aromatic substitution, with loss of methyl phosphate) in competition with attack at phosphorus, most notably with hydroxide and with primary amines.46 Due to the small size of the methyl group it is sterically susceptible to nucleophilic attack in phosphate esters the hydrolysis of the dimethyl phosphate anion occurs almost exclusively by C-O bond fission.4 With larger or less labile leaving groups, even... 

Figure 2 shows that there is also no positive deviation of the rate constant for reaction with water in a correlation of log k for the reactions of oxygen nucleophiles with the monoanions of phosphorylated y-picoline and with methyl dinitrophenyl phosphate (27). Methyl dinitrophenyl phosphate reacts with RO by a concerted bimolecular substitution. The fit of the rate constant for water to this correlation is consistent with a concerted bimolecular reaction mechanism of water with phosphorylated y-picoline. 

Figure 2. Correlation of the rate constants for the reaction of nucleophilic reagents with phosphorylated y-picoline monoanion and methyl 2,4-dinitrophenyl phosphate monoanion. The line has a slope of 0.51 (79).

Domingos, J.B., Longhinotti, E., Brandao, T.A.S., Bunton, C.A., Santos, L.S., Eber-lin, M.N., Nome, F. (2004) Mechanisms of Nucleophilic Substitution Reactions of Methylated Hydroxylamines with Bis(2,4-dinitrophenyl)phosphate. Mass Spectro-metric Identification of Key Intermediates. J. Org. Chem. 69 6024-6033. 

Pd-catalyTxd coupling of vinylic tellurides with alkynes Pd-Te cationic intermediates were, for the first time, intercepted and transferred to the gas phase for structural characterization. Nucleophilic substitution reactions of methylated hydroxylamines with bis(2,4-dinitrophenyl) phosphate... 

Another interesting approach using ESI(—)-MS was used to probe the mechanism of nucleophilic substitution reactions of methylated hydroxylamines, hydrazine and hydrogen peroxide with bis(2,4-dinitrophenyl)phosphate (BDNPP) [86]. ESI-MS screening of the reaction was performed to fish ionic intermediates and products directly from solution into the gas phase, and the key intermediates were fully... 

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