44515-17-5Relevant articles and documents
Reactivity of the insecticide fenitrothion toward O and N nucleophiles
Rougier, Natalia M.,Vico, Raquel V.,De Rossi, Rita H.,Bujan, Elba I.
, p. 3427 - 3436 (2010)
The reactivity of Fenitrothion (1) toward several O- and N-based nucleophiles, including ambident and α-nucleophiles, was investigated in basic media at 25 °C in water containing 2% 1,4-dioxane. In the reactions with HO- and HOO- quantitative formation of 3-methyl-4-nitrophenoxide (2) was observed indicating a SN2(P) pathway. In the reactions with NH2OH, NH2O-, and BuNH2, demethylfenitrothion (4) was formed along with 2, indicating competition between the SN2(P) and SN2(C) pathways; no evidence of a SNAr pathway was observed in any case. The observed rate constants were dissected into the values corresponding to the SN2(P) and SN2(C) pathways. The yield of 4 depends on the nucleophile and on the pH of the reaction, being the main product in the case of BuNH2. With HOO-, NH2OH, and NH 2O- a significant α-effect was observed, confirming the participation of the nucleophile in the rate-limiting step of the reaction.
31P NMR Kinetic Studies on Fenitrothion Hydrolysis in the Presence of Ag+ and Hg2+ Ions
Choi, Hojune,Yang, Kiyull,Koo, In Sun
, p. 707 - 710 (2015/07/20)
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Study on the transesterification of methyl aryl phosphorothioates in methanol promoted by Cd(II), Mn(II), and a synthetic Pd(II) complex
Edwards, David R.,Neverov, Alexei A.,Brown, R. Stan
scheme or table, p. 1786 - 1797 (2011/04/23)
Methanol solutions containing Cd(II), Mn(II), and a palladacycle, (dimethanol bis(N,N-dimethylbenzylamine-2C,N)palladium(II) (3), are shown to promote the methanolytic transesterification of O-methyl O-4-nitrophenyl phosphorothioate (2b) at 25 °C with impressive rate accelerations of 10 6-1011 over the background methoxide promoted reaction. A detailed mechanistic investigation of the methanolytic cleavage of 2a-d having various leaving group aryl substitutions, and particularly the 4-nitrophenyl derivative (2b), catalyzed by Pd-complex 3 is presented. Plots of k obs versus palladacycle [3] demonstrate strong saturation binding to form 2b:3. Numerical fits of the kinetic data to a universal binding equation provide binding constants, Kb, and first order catalytic rate constants for the methanolysis reaction of the 2b:3 complex (kcat) which, when corrected for buffer effects, give corrected (kcat corr) rate constants. A sigmoidal shaped plot of log(k catcorr) versus sspH (in methanol) for the cleavage of 2b displays a broad sspH independent region from 5.6 ≥ sspH ≥ ～10 with a k minimum = (1.45 ± 0.24) × 10-2 s-1 and a [lyoxide] dependent wing plateauing above a kinetically determined sspKa of 12.71 ± 0.17 to give a k maximum = 7.1 ± 1.7 s-1. Bronsted plots were constructed for reaction of 2a-d at sspH 8.7 and 14.1, corresponding to reaction in the midpoints of the low and high s spH plateaus. The Bronsted coefficients (βLG) are computed as -0.01 ± 0.03 and -0.86 ± 0.004 at low and high sspH, respectively. In the low sspH plateau, and under conditions of saturating 3, a solvent deuterium kinetic isotope effect of kH/kD = 1.17 ± 0.08 is observed; activation parameters (ΔHPd? = 14.0 ± 0.6 kcal/mol and ΔSPd?= -20 ± 2 cal/mol?K) were obtained for the 3-catalyzed cleavage reaction of 2b. Possible mechanisms are discussed for the reactions catalyzed by 3 at low and high sspH. This catalytic system is shown to promote the methanolytic cleavage of O,O-dimethyl phosphorothioate in CD3OD, producing (CD3O)2P=O(S-) with a half time for reaction of 34 min.
