An interesting and recyclable activated carbon/water catalytic system for efficient synthesis of pyrrolo[1,2-a]quinoxaline derivatives was developed. The intramolecular C-N and C-C bond can be easily constructed in wa...An interesting and recyclable activated carbon/water catalytic system for efficient synthesis of pyrrolo[1,2-a]quinoxaline derivatives was developed. The intramolecular C-N and C-C bond can be easily constructed in water under mild condition. This reaction features a broad substrate scope, a good tolerance to water and air, metal-free, additive-free and redox reagent-free.展开更多
An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic a...An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic amount of CuSO4 at 130 ℃ using water as a green solvent. The products were obtained in moderate to excellent yields;more importantly, the use of toxic ligands and solvents was avoided. A broad range of aryl boronic acids and scalable processes make this methodology valuable and versatile for the synthesis of a broad range of aryl sulfides.展开更多
The formamide-titanium oxide interaction mechanism is a research target of great importance for understanding the elementary events of the origin of life: the synthesis of nucleoside bases and formation of biological ...The formamide-titanium oxide interaction mechanism is a research target of great importance for understanding the elementary events of the origin of life: the synthesis of nucleoside bases and formation of biological molecules needed for life. Titanium oxide (TiO2) can act as a strongly adsorbing surface or a catalytic material. In the present study, a comparative molecular dynamics analysis performed to clarify the adsorbing and diffusion properties of liquid formamide on a TiO2 surface in the presence of water molecules. The structural features of the formamide concentration effect (the accumulation of molecules) on a TiO2 surface in the presence and absence of water solvent are cleared up. Modification of the formamide diffusion abilities mediated by a water solvent is observed to correlate with the formamide-water concentration distribution on the surface.展开更多
在M06/6-311++G(d,p)和MN15/6-311++G(2df,pd)双水平,研究了α-丙氨酸(α-Ala)与Cr^(3+)的配合物S-α-Ala·Cr^(3+)的手性反转,结合极化连续介质的SMD模型方法研究了水溶剂的作用。S-α-Ala·Cr^(3+)的手性反转有3个通道:a通道...在M06/6-311++G(d,p)和MN15/6-311++G(2df,pd)双水平,研究了α-丙氨酸(α-Ala)与Cr^(3+)的配合物S-α-Ala·Cr^(3+)的手性反转,结合极化连续介质的SMD模型方法研究了水溶剂的作用。S-α-Ala·Cr^(3+)的手性反转有3个通道:a通道是氨基N作质子转移媒介;b通道是羰基O和氨基N联合作质子转移媒介;c通道是羰基O作质子转移媒介。势能面研究表明:气相S-α-Ala·Cr^(3+)在a、b、c通道手性反转的活化能分别是295.6、305.5、123.6 k J/mol;水液相S-α-Ala·Cr^(3+)在a通道的活化能降至95.8 k J/mol,在b通道和c通道的活化能降至108.0 k J/mol。结果表明:气相α-Ala·Cr^(3+)能缓慢消旋,因此光学纯的α-Ala·Cr^(3+)不能在气固相下长期保存;水液相下α-Ala·Cr^(3+)能缓慢消旋,α-Ala·Cr^(3+)只能短期且少量的用于生命体同补α-Ala和Cr^(3+)。展开更多
基金the financial support from the National Natural Science Foundation of China (Nos. 21432009, 21672200, 21472177, 21772185 and 21801233)for the assistance of the product characterization from the Chemistry Experiment Teaching Center of University of Science and Technology of Chinasupported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB20000000)
文摘An interesting and recyclable activated carbon/water catalytic system for efficient synthesis of pyrrolo[1,2-a]quinoxaline derivatives was developed. The intramolecular C-N and C-C bond can be easily constructed in water under mild condition. This reaction features a broad substrate scope, a good tolerance to water and air, metal-free, additive-free and redox reagent-free.
基金Funded by the National Natural Science Foundation of China(No.21571144)
文摘An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic amount of CuSO4 at 130 ℃ using water as a green solvent. The products were obtained in moderate to excellent yields;more importantly, the use of toxic ligands and solvents was avoided. A broad range of aryl boronic acids and scalable processes make this methodology valuable and versatile for the synthesis of a broad range of aryl sulfides.
文摘The formamide-titanium oxide interaction mechanism is a research target of great importance for understanding the elementary events of the origin of life: the synthesis of nucleoside bases and formation of biological molecules needed for life. Titanium oxide (TiO2) can act as a strongly adsorbing surface or a catalytic material. In the present study, a comparative molecular dynamics analysis performed to clarify the adsorbing and diffusion properties of liquid formamide on a TiO2 surface in the presence of water molecules. The structural features of the formamide concentration effect (the accumulation of molecules) on a TiO2 surface in the presence and absence of water solvent are cleared up. Modification of the formamide diffusion abilities mediated by a water solvent is observed to correlate with the formamide-water concentration distribution on the surface.
文摘在M06/6-311++G(d,p)和MN15/6-311++G(2df,pd)双水平,研究了α-丙氨酸(α-Ala)与Cr^(3+)的配合物S-α-Ala·Cr^(3+)的手性反转,结合极化连续介质的SMD模型方法研究了水溶剂的作用。S-α-Ala·Cr^(3+)的手性反转有3个通道:a通道是氨基N作质子转移媒介;b通道是羰基O和氨基N联合作质子转移媒介;c通道是羰基O作质子转移媒介。势能面研究表明:气相S-α-Ala·Cr^(3+)在a、b、c通道手性反转的活化能分别是295.6、305.5、123.6 k J/mol;水液相S-α-Ala·Cr^(3+)在a通道的活化能降至95.8 k J/mol,在b通道和c通道的活化能降至108.0 k J/mol。结果表明:气相α-Ala·Cr^(3+)能缓慢消旋,因此光学纯的α-Ala·Cr^(3+)不能在气固相下长期保存;水液相下α-Ala·Cr^(3+)能缓慢消旋,α-Ala·Cr^(3+)只能短期且少量的用于生命体同补α-Ala和Cr^(3+)。