Cyclodextrin-Mediated Hydrolyses of Novel Phosphotriesters

Abstract

The basic cleavages (pH 10) of p-nitrophenyl diphenyl phosphate (1, PNPDPP), p-nitrophenyl 1,8-naphthyl phosphate (2, PNPNP), and p-nitrophenyl biphenyl phosphate (3, PNPBPP) were mediated by α-, β-, and γ-cyclodextrins. Derived kinetic parameters revealed substantial selectivity for the β-CD/PNPNP system, with efficient cyclodextrin-catalyzed cleavage characterized by a high value of k cat/K diss.

Stabilization of the pesticide Fenitrothion towardOandNnucleophiles in the presence of cyclodextrins

“…[18] There are several examples in the literature of changes in reaction rates due to the presence of linear sugars or monosaccharides. [19][20][21][22] The inhibition produced by complexation with β-CD is greater for the reaction of 1 with HOO À than for the hydrolysis reaction. If the reaction center is buried in the CD's cavity, the reaction with a bulkier nucleophile would lead to a greater inhibition as it is observed when we compared the reactions with HOO À or HO À .…”

“…Therefore, in Scheme 5, the pathways that imply the complexed amines can be discarded; the observed rate constant for the mechanism of the reaction of 1 with BuNH 2 is given by Eqn (21), which has the same mathematical form of Eqn (1) with parameters a and b given by Eqns (22) and (23), and parameter c is given by Eqn (20).…”

Organophosphorus Supramolecular Chemistry Part 1. Receptors for Organophosphorus Compounds

“…CDs were also reported to catalyze the cleavage of various phosphate, pyrophosphate and phosphonate esters [98][99][100][101][102]. The fission occurs by nucleophilic mechanism resulting in a formation of phosphorylated cyclodextrin as intermediate [98][99][100][101] or CD acts as a general base catalyst for the attack of water [100,101].…”

“…The fission occurs by nucleophilic mechanism resulting in a formation of phosphorylated cyclodextrin as intermediate [98][99][100][101] or CD acts as a general base catalyst for the attack of water [100,101]. Both the mechanism and the acceleration ratio of cleavage strongly depend on the structure of substrates and size of CD, thereby on the structure of the formed complexes.…”

Enhanced nucleophilic reactivity of hydroxamate ions in some novel micellar systems for the cleavage of Parathion

“…Organophosphorous compounds are widely used as pesticides, insecticides and chemical warfare agents [1][2][3]. Despite several decades of research, there continues to be a need for new and improved methods for the detoxification of highly neurotoxic organophosphorous compounds.…”