Hydrodesulfurization(HDS)reaction can significantly reduce the viscosity and sulfur content of heavy oil,while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still unclear.The HD...Hydrodesulfurization(HDS)reaction can significantly reduce the viscosity and sulfur content of heavy oil,while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still unclear.The HDS experiment of tetrahydrothiophene catalyzed by nickel phosphide(Ni_(2)P)is carried out at 200-300°C.The results indicate that the H_(2)S production under the catalysis of Ni_(2)P increases obviously within 200-250°C.The main gas products of HDS reaction are butane,butene and H_(2)S.Meanwhile,the mechanism of tetrahydrothiophene catalyzed by Ni_(2)P is analyzed based on Density Functional Theory(DFT).It is revealed that the adsorption model is most stable when tetrahydrothiophene is vertically adsorbed on the V-Ni-Hcp1 site of Ni_(2)P(001).The C-S bond is elongated and the C-C bond is shortened after adsorption.Hydrogenation(HYD)is the most possible reaction route of tetrahydrothiophene on Ni_(2)P(001)surface.There are two routes with the lowest activation energy,which are C_(4)H_(8)S→C_(4)H_(8)SH^(*)→C_(4)H_(9)SH^(*)→C_(4)H_(10)+H_(2)S and C_(4)H_(8)S→C_(4)H9S^(*)→C_(4)H_(9)^(*)+SH^(*)→C_(4)H_(10)+H_(2)S.Butane and H_(2)S are produced in the reaction,corresponding to the experimental results.This study provides a basis for understanding of the HDS mechanism of tetrahydrothiophene catalyzed by Ni_(2)P.展开更多
A mild and efficient enantioselective one-pot synthesis of β-sulfonyl ketones and trisubstituted tetrahydrothiophenes via introducing 1,4-dithiane-2,5-diol to the simple kinetic resolution of β-sulfonyl ketones has ...A mild and efficient enantioselective one-pot synthesis of β-sulfonyl ketones and trisubstituted tetrahydrothiophenes via introducing 1,4-dithiane-2,5-diol to the simple kinetic resolution of β-sulfonyl ketones has been described herein. The one-pot reaction sequence including kinetic resolution and cascade sulfa-Michael/Aldol reaction proceeded successively to afford corresponding sulfonyl ketones and tetrahydrothiophenes with high enantioselectivities（85%-98% ee and 84%-95% ee）.展开更多
基金the financial support provided by the National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05012002-005)National Natural Science Foundation of China(No.51874333)Natural Science Foundation of Shandong Province,China(No.ZR2017MEE030)
文摘Hydrodesulfurization(HDS)reaction can significantly reduce the viscosity and sulfur content of heavy oil,while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still unclear.The HDS experiment of tetrahydrothiophene catalyzed by nickel phosphide(Ni_(2)P)is carried out at 200-300°C.The results indicate that the H_(2)S production under the catalysis of Ni_(2)P increases obviously within 200-250°C.The main gas products of HDS reaction are butane,butene and H_(2)S.Meanwhile,the mechanism of tetrahydrothiophene catalyzed by Ni_(2)P is analyzed based on Density Functional Theory(DFT).It is revealed that the adsorption model is most stable when tetrahydrothiophene is vertically adsorbed on the V-Ni-Hcp1 site of Ni_(2)P(001).The C-S bond is elongated and the C-C bond is shortened after adsorption.Hydrogenation(HYD)is the most possible reaction route of tetrahydrothiophene on Ni_(2)P(001)surface.There are two routes with the lowest activation energy,which are C_(4)H_(8)S→C_(4)H_(8)SH^(*)→C_(4)H_(9)SH^(*)→C_(4)H_(10)+H_(2)S and C_(4)H_(8)S→C_(4)H9S^(*)→C_(4)H_(9)^(*)+SH^(*)→C_(4)H_(10)+H_(2)S.Butane and H_(2)S are produced in the reaction,corresponding to the experimental results.This study provides a basis for understanding of the HDS mechanism of tetrahydrothiophene catalyzed by Ni_(2)P.
基金supported by the Fundamental Research Funds for the Central Universities in China(No. CQDXWL-2014-2003)the Scientific Research Foundation of China(No. 21402016)Graduate Scientific Research and Innovation Foundation of Chongqing, China (Nos. CYS17044, CYB16032)
文摘A mild and efficient enantioselective one-pot synthesis of β-sulfonyl ketones and trisubstituted tetrahydrothiophenes via introducing 1,4-dithiane-2,5-diol to the simple kinetic resolution of β-sulfonyl ketones has been described herein. The one-pot reaction sequence including kinetic resolution and cascade sulfa-Michael/Aldol reaction proceeded successively to afford corresponding sulfonyl ketones and tetrahydrothiophenes with high enantioselectivities（85%-98% ee and 84%-95% ee）.
