188526-94-5

Upstream product

• 224575-62-6 2,2,5,5-tetramethyl-3-(1-phenylethoxy)-4-diethylphosphono-3-azahexane 
• 224575-61-5 N-tert-butyl-N-(1-diethoxyphosphoryl-2,2-dimethylpropyl)-O-(benzyl)hydroxylamine 

Downstream Products

• 224575-61-5 N-tert-butyl-N-(1-diethoxyphosphoryl-2,2-dimethylpropyl)-O-(benzyl)hydroxylamine 
• 224575-62-6 2,2,5,5-tetramethyl-3-(1-phenylethoxy)-4-diethylphosphono-3-azahexane 
• 647018-70-0 (1-{tert-butyl-[1-(methyl-phenyl-carbamoyl)-ethoxy]-amino}-2,2-dimethyl-propyl)-phosphonic acid diethyl ester 
• 647018-71-1 (1-{tert-butyl-[1-methyl-1-(methyl-phenyl-carbamoyl)-ethoxy]-amino}-2,2-dimethyl-propyl)-phosphonic acid diethyl ester 
• 654636-62-1 N-(2-methyl-2-propyl)-N-(1-diethylphosphono-2,2-dimethylpropyl)-O-(2-carboxyprop-2-yl)hydroxylamide 

Relevant academic research and scientific papers

Chemically triggered C-ON bond homolysis in alkoxyamines. 6. Effect of the counteranion

We showed (J. Org. Chem. 2012, 77) 9634) that the activation by methylation of pyridyl-based alkoxyamine 1 increased with the hydrogen bond donor properties of solvents. In this paper, activation of 1 by protonation with acids, CF3COOH and CSA, in tert-butylbenzene (t-BuPh) and in H 2O/MeOH afforded, with CF3COOH, kd 28-fold larger in H2O/MeOH than in t-BuPh, whereas it was only 4-fold larger when CSA was used. This puzzling observation was ascribed to the dissociation of the intimate ion pair.

H-transfer reaction during decomposition of N-(2-methylpropyl)- N-(1-diethylphosphono-2,2-dimethylpropyl)-N-oxyl (SG1)-based alkoxyamines

Thermal decomposition of four tertiary N-(2-methylpropyl)-N-(1- diethylphosphono-2,2-dimethylpropyl)-N-oxyl (SG1)-based alkoxyamines (SG1-C(Me)2-C(O)-OR, R = Me, tBu, Et, H) has been studied at different experimental conditions using 1/su

Long-range polar and steric effects in propionate-SG1-type alkoxyamines (SG1-CHMeCOOX): A multiparameter analysis

The effects of the substituent X on the homolysis rate constants (k d) of SG1-propionate type alkoxyamines (SG1-CHMeCOOX) are analyzed by a multiparametric equation with v, the steric constant and σI, the polar inductive/field Hammett constant of X. An influence of long-range polar and steric effects on kd was observed, that is, decrease in kd with increasing size of the X group and increase in kd with increasing polarity of the X group. Copyright

Alkoxyamine C-ON bond homolysis: Stereoelectronic effects

Alkoxyamines and persistent nitroxides are important regulators of nitroxide-mediated radical polymerization (NMP) reactions. Because polymerization times decrease with an increase in the rate constant for the homolysis of the C-ON bond between the polyme

Factors influencing C-ON bond homolysis in alkoxyamines: Unexpected behavior of SG1 (N-(2-methyl-2-propyl)-N-(1-diethylphosphono-2,2-dimethylpropyl) -N-oxyl)-based alkoxyamines

Alkoxyamines and persistent nitroxides are important regulators of nitroxide-mediated radical polymerization (NMP). Since the polymerization time decreases with the increasing equilibrium constant K (kdk c), i.e., the increasing rate constant kd of the homolysis of the C-ON bond between the polymer chain and the nitroxide moiety, the factors influencing the cleavage rate constants are of considerable interest. SG1-based alkoxyamines have turned out to be the most potent alkoxyamine family to use for NMP of various monomers. Therefore, it is of high interest to determine the factors which make SG1 derivatives better regulators than TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl) derivatives. Contrary to what we had observed with TEMPO derivatives, we observed two relationships for the plot Ea vs BDE(C-H), one for the nonpolar released alkyl radicals (E a (kJ/mol) = -133.0 + 0.72BDE) and the other one for the polar released alkyl radicals (Ea (kJ/mol) = -137.0 + 0.69BDE). However, for both families (SG1 and TEMPO derivatives), the rate constants kd of the C-ON bond homolysis were correlated to the cleavage temperature T c (log(kd(s-1)) = 1.51 -0.058Tc). Such correlations should help to design new alkoxyamines to use as regulators and to improve the tuning of NMP experiments.

Entropy control of the cross-reaction between carbon-centered and nitroxide radicals

Absolute rate constants for the cross-coupling reaction of several carbon-centered radicals with various nitroxides and their temperature dependence have been determined in liquids by kinetic absorption spectroscopy. The rate constants range from 5 M-1 s-1 to 2.3 × 109 M-1 s-1 and depend strongly on the structure of the nitroxide and the carbon-centered radical. Grossly, they decrease with increasing rate constant of the cleavage of the corresponding alkoxyamine. In many cases, the temperature dependence shows a non-Arrhenius behavior. A model assuming a short-lived intermediate that is hindered to form the coupling product by an unfavorable activation entropy leads to a satisfactory analytic description. However, the behavior is more likely due to a barrierless single-step reaction with a low exothermicity where the free energy of activation is dominated by a large negative entropy term.