ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production...ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production of caprolactam are based on either benzene or tolueneI21. Caprolactam is synthesized by the Beckmann rearrangement of cyclohexanone oxime with fuming sulfuric acid or sulfuric acid as the reaction medium, and cyclohexanone oxime is produced by the reaction between cyclohexanone and hydro- xylamine（only one exception is the Toray PNC process）.展开更多
A simple and efficient approach for the synthesis of e-caprolactam via the liquid phase nitrosation of cyclohexane and nitrosyl sulfuric acid in the presence of concentrated sulfuric acid has been developed. A series ...A simple and efficient approach for the synthesis of e-caprolactam via the liquid phase nitrosation of cyclohexane and nitrosyl sulfuric acid in the presence of concentrated sulfuric acid has been developed. A series of novel A1VPO composites were prepared by an impregnation method and the composites were then employed to catalyze the nitrosation reaction of cyclohexane and nitrosyl sulfuric acid. Compared to the reaction using fuming sulfuric acid, the selectivity for the desired product was significantly improved using this one-step catalytic process. This method affords a shortcut to prepare ecaprolactam and its analogs from cyclohexane.展开更多
The catalysis of chloridized metalloporphyrins in the oxidation of cyclohexane to adipic acid was systemati-cally investigated.The turnover numbers(TON)data of 19 catalysts were obtained experimentally under optimal r...The catalysis of chloridized metalloporphyrins in the oxidation of cyclohexane to adipic acid was systemati-cally investigated.The turnover numbers(TON)data of 19 catalysts were obtained experimentally under optimal reac-tion conditions,and 2.4x106 TON for T(o-Cl)PP-MnIIICl catalyst at 2.0x10–6 mol/L of dosage was reached under the conditions of dioxygen pressure of 2.5 MPa at 150°C for 4 h.This was the best result reported for this reaction up to now.The QSAR models for each concerned metallopor-phyrin were established,where the catalytic activity was significantly correlated with the ELUMO(the energy level of the lowest unoccupied molecule orbit)and LM-N(the bond length between metal-nitrogen atoms).Using the QSAR models,four new metalloporphyrins with substituted nitro group were designed,and their catalytic activities were predicted.The experimental TON data of newly designed porphyrins were in good agreement with the predicted ones,and the square of their correlation coefficient was more than 0.958.The above results demonstrated that the proposed structure-activity relationship model could be applied to design some new metalloporphyrin catalysts,and to predict their catalytic activity in cyclohexane oxidation.展开更多
基金Supported by the National Natural Science Foundation of China(Nos 20233040 and 20572021)
文摘ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production of caprolactam are based on either benzene or tolueneI21. Caprolactam is synthesized by the Beckmann rearrangement of cyclohexanone oxime with fuming sulfuric acid or sulfuric acid as the reaction medium, and cyclohexanone oxime is produced by the reaction between cyclohexanone and hydro- xylamine（only one exception is the Toray PNC process）.
文摘A simple and efficient approach for the synthesis of e-caprolactam via the liquid phase nitrosation of cyclohexane and nitrosyl sulfuric acid in the presence of concentrated sulfuric acid has been developed. A series of novel A1VPO composites were prepared by an impregnation method and the composites were then employed to catalyze the nitrosation reaction of cyclohexane and nitrosyl sulfuric acid. Compared to the reaction using fuming sulfuric acid, the selectivity for the desired product was significantly improved using this one-step catalytic process. This method affords a shortcut to prepare ecaprolactam and its analogs from cyclohexane.
基金supported by the Key Project of Natural Science Foundation of Beijing(Grant No.2061001).
文摘The catalysis of chloridized metalloporphyrins in the oxidation of cyclohexane to adipic acid was systemati-cally investigated.The turnover numbers(TON)data of 19 catalysts were obtained experimentally under optimal reac-tion conditions,and 2.4x106 TON for T(o-Cl)PP-MnIIICl catalyst at 2.0x10–6 mol/L of dosage was reached under the conditions of dioxygen pressure of 2.5 MPa at 150°C for 4 h.This was the best result reported for this reaction up to now.The QSAR models for each concerned metallopor-phyrin were established,where the catalytic activity was significantly correlated with the ELUMO(the energy level of the lowest unoccupied molecule orbit)and LM-N(the bond length between metal-nitrogen atoms).Using the QSAR models,four new metalloporphyrins with substituted nitro group were designed,and their catalytic activities were predicted.The experimental TON data of newly designed porphyrins were in good agreement with the predicted ones,and the square of their correlation coefficient was more than 0.958.The above results demonstrated that the proposed structure-activity relationship model could be applied to design some new metalloporphyrin catalysts,and to predict their catalytic activity in cyclohexane oxidation.
