334-25-8Relevant academic research and scientific papers
Heterolytic (2 e) vs Homolytic (1 e) Oxidation Reactivity: N?H versus C?H Switch in the Oxidation of Lactams by Dioxirans
Annese, Cosimo,D'Accolti, Lucia,Fusco, Caterina,Licini, Giulia,Zonta, Cristiano
supporting information, p. 259 - 262 (2017/01/17)
Dioxiranes are powerful oxidants that can act via two different mechanisms: 1) homolytic (H abstraction and oxygen rebound) and 2) heterolytic (electrophilic oxidation). So far, it has been reported that the nature of the substrate dictates the reaction mode independently from the dioxirane employed. Herein, we report an unprecedented case in which the nature of the dioxirane rules the oxidation chemoselectivity. In particular, a switch from C?H to N?H oxidation is observed in the oxidation of lactams moving from dimethyl dioxirane (DDO) to methyl(trifluoromethyl)dioxirane (TFDO). A physical organic chemistry study, which combines the oxidation with two other dioxiranes methyl(fluoromethyl)dioxirane, MFDO, and methyl(difluoromethyl)dioxirane, DFDO, with computational studies, points to a diverse ability of the dioxiranes to either stabilize the homo or the heterolytic pathway.
PRODUCTION OF CAPROLACTAM FROM ADIPIC ACID
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Paragraph 0061; 0062, (2013/09/12)
Processes are disclosed for the conversion of adipic acid to caprolactam employing a chemocatalytic reaction in which an adipic acid substrate is reacted with ammonia and hydrogen, in the presence of particular heterogeneous catalysts and employing unique solvents. The present invention also enables the conversion of other adipic acid substrates, such as mono-esters of adipic acid, di-esters of adipic acid, mono-amides of adipic acid, di-amides of adipic acid, and salts thereof to caprolactam. Solvents useful in the process that do not react with ammonia are also disclosed. Catalyst supports are disclosed which catalyze the reaction of the substrate with ammonia in the absence of added metal. Metals on the catalyst supports comprise ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and/or platinum (Pt). Heterogeneous catalysts comprising ruthenium (Ru) and rhenium (Re) on titania and/or zirconia supports are also disclosed. Further, disclosed are products produced by such processes, as well as products producible from such products.
Optimization of adiponitrile hydrolysis in subcritical water using an orthogonal array design
Duan, Peigao,Wang, Yuanyuan,Yang, Yan,Dai, Liyi
body text, p. 241 - 258 (2009/10/17)
A study of the hydrolysis of adiponitrile (ADN) was performed in subcritical water to research the dependence on experimental conditions. An L25(56) orthogonal array design (OAD) with six factors at five levels using statistical analysis was employed to optimize the experimental conditions for each product in which the interactions between the variables were temporarily neglected. The six factors were adiponitrile concentration (ADN c, wt%), temperature (T), time (t h), percentage of additives (reactant/additive, wt/wt%), additives (A), and pressure (p, MPa). The effects of these parameters were investigated using the analysis of variance (ANOVA) to determine the relationship between experimental conditions and yield levels of different products. The results showed that (ADN c) and T had a significant influence on the yields of adipamide, adipamic acid, and adipic acid at p0.05. Time was the statistically significant factor for the yield of 5-cyanovalermic acid at p0.05 and (ADN c) was the significant factor for the yield of 5-cyanovaleramide at p0.1. Finally, five supplementary experiments were conducted under optimized conditions predicted by the Taguchi method; the results showed that the yield obtained of each product was no lower than that of the highest in the 25 experiments. Carbon balance was calculated to demonstrate the validity of the experimental technique and the reliability of the results. Based on the experimental results, a possible reaction mechanism was proposed.
