A combination of HBr and trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane as anew and powerful oxidant was found effective for facile brotnination of different aromatic compounds at room temperature in water as a gr...A combination of HBr and trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane as anew and powerful oxidant was found effective for facile brotnination of different aromatic compounds at room temperature in water as a green solvent.Mild reaction conditions,high selectivity and yield,high reaction rate and non-toxicity are some of the major advantages of this synthetic protocol.展开更多
The title compound of trans-3-phenyl-2-propenoic acid （C9H802）, a main active organic acid of cinnamon bark and styrax, was obtained by oxidization from trans-3-phenyl-2-propenaldehyde and characterized by X-ray dif...The title compound of trans-3-phenyl-2-propenoic acid （C9H802）, a main active organic acid of cinnamon bark and styrax, was obtained by oxidization from trans-3-phenyl-2-propenaldehyde and characterized by X-ray diffraction analysis. It crystallizes in monoclinic system, space group P21/n with a = 5.55916（10）, b = 17.4870（3）, c = 7.70677（13） A, V = 744.89（2） A3, Z= 4, Dc= 1.321 g/cm3, Mr = 148.15, F（000） = 312, and/t μ=0.764 mm-1. A total of 2661 reflections with 1447 unique ones （Rint = 0.0137） were collected, in which 1447 were observed （I〉2σ（/））. There were two C9H802 molecules in an asymmetric unit. The structural unit was a dimer formed by the hydrogen bonding of the oxygen atom of carbonyl group and the hydrogen atom of hydroxyl group. A 3D layer structure was formed through hydrogen bonds and Van der Walls＇ forces.展开更多
The monofunctional substitution reactions between trans-[PtCl（H2O）（NH3）（pip）]＋,trans-[Pt（H2O）2（NH3）（pip）]2＋,trans-[PtCl（H2O）（pip）2]＋,trans-[Pt（H2O）2（pip）2]2＋ （pip = piperidine） and adenine/gu...The monofunctional substitution reactions between trans-[PtCl（H2O）（NH3）（pip）]＋,trans-[Pt（H2O）2（NH3）（pip）]2＋,trans-[PtCl（H2O）（pip）2]＋,trans-[Pt（H2O）2（pip）2]2＋ （pip = piperidine） and adenine/guanine nucleotides are explored by using B3LYP hybrid functional and IEF-PCM salvation models. For the trans-[Pt（H2O）2（NH3）（pip）]2＋ and trans-[PtCl（H2O）（NH3）（pip）]＋ complexes,the computed barrier heights in aqueous solution are 13.5/13.5 and 11.6/11.6 kcal/mol from trans-Pt-chloroaqua complex to trans/cis-monoadduct for adenine and guanine,and the corresponding values are 20.7/20.7 and 18.8/18.8 kcal/mol from trans-Pt-diaqua complex to trans/cis-monoadduct for adenine and guanine,respectively. For trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋,the corresponding values are 21.5/21.3 and 19.4/19.4 kcal/mol,and 26.0/26.0 and 20.7/20.8 kal/mol for adenine and guanine,respectively. Our calculations demonstrate that the barrier heights of chloroaqua are lower than the corresponding values of diaqua for adenine and guanine. In addition,the free energies of activation for guanine in aqueous solution are all smaller than that for adenine,which predicts a preference of 1.9 kcal/mol when trans-[PtCl（H2O）（NH3）（pip）]＋ and trans-[Pt（H2O）2（NH3）（pip）]2＋ are the active agents and ～1.9 and ～ 5.3 kcal/mol when trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋ are the active agents,respectively. For the reaction of trans-Pt-chloroaqua （or diaqua） to cis-monoadduct,we obtain the same transition-state structure as from the reaction of trans-Pt-chloroaqua （or diaqua） to trans-monoadduct,which seems that the trans-Pt-chloroaqua （or diaqua） complex can generate trans-or cis-monoadduct via the same transition-state.展开更多
To study new natural products, we used ODS （YMC, Kyoto, Japan） and silica gel column chromatography to separate compounds in Cercis chinensis Bunge （Leguminosae）. A new stilbene, trans- 3, 5, 3＇, 4＇-tetrahydroxy...To study new natural products, we used ODS （YMC, Kyoto, Japan） and silica gel column chromatography to separate compounds in Cercis chinensis Bunge （Leguminosae）. A new stilbene, trans- 3, 5, 3＇, 4＇-tetrahydroxy-4-methylstilbene （1）, along with 10 known compounds, namely piceatannol （2）, dihydromyricetin （3）, catechin （4）, dihydrorobinetin （5）, menisdaurin （6）, lithospermoside （7）, teatannin （8）, dasycarponin （9）, β-sitosterol （10）, and daucosterin （11）, was isolated from C. chinensis. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 2-6 and 9 were isolated from the genus Cercis Linn. for the first time.展开更多
文摘A combination of HBr and trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane as anew and powerful oxidant was found effective for facile brotnination of different aromatic compounds at room temperature in water as a green solvent.Mild reaction conditions,high selectivity and yield,high reaction rate and non-toxicity are some of the major advantages of this synthetic protocol.
基金The China Agriculture Research System(Grant No.CARS-21)the public welfare research special project in General Administration of Quality Supervision,Inspection and Quarantine of the People’s Republic of China(Grant No.201210209)
文摘The title compound of trans-3-phenyl-2-propenoic acid （C9H802）, a main active organic acid of cinnamon bark and styrax, was obtained by oxidization from trans-3-phenyl-2-propenaldehyde and characterized by X-ray diffraction analysis. It crystallizes in monoclinic system, space group P21/n with a = 5.55916（10）, b = 17.4870（3）, c = 7.70677（13） A, V = 744.89（2） A3, Z= 4, Dc= 1.321 g/cm3, Mr = 148.15, F（000） = 312, and/t μ=0.764 mm-1. A total of 2661 reflections with 1447 unique ones （Rint = 0.0137） were collected, in which 1447 were observed （I〉2σ（/））. There were two C9H802 molecules in an asymmetric unit. The structural unit was a dimer formed by the hydrogen bonding of the oxygen atom of carbonyl group and the hydrogen atom of hydroxyl group. A 3D layer structure was formed through hydrogen bonds and Van der Walls＇ forces.
基金supported from the National Natural Science Foundation of China (No. 20971056)
文摘The monofunctional substitution reactions between trans-[PtCl（H2O）（NH3）（pip）]＋,trans-[Pt（H2O）2（NH3）（pip）]2＋,trans-[PtCl（H2O）（pip）2]＋,trans-[Pt（H2O）2（pip）2]2＋ （pip = piperidine） and adenine/guanine nucleotides are explored by using B3LYP hybrid functional and IEF-PCM salvation models. For the trans-[Pt（H2O）2（NH3）（pip）]2＋ and trans-[PtCl（H2O）（NH3）（pip）]＋ complexes,the computed barrier heights in aqueous solution are 13.5/13.5 and 11.6/11.6 kcal/mol from trans-Pt-chloroaqua complex to trans/cis-monoadduct for adenine and guanine,and the corresponding values are 20.7/20.7 and 18.8/18.8 kcal/mol from trans-Pt-diaqua complex to trans/cis-monoadduct for adenine and guanine,respectively. For trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋,the corresponding values are 21.5/21.3 and 19.4/19.4 kcal/mol,and 26.0/26.0 and 20.7/20.8 kal/mol for adenine and guanine,respectively. Our calculations demonstrate that the barrier heights of chloroaqua are lower than the corresponding values of diaqua for adenine and guanine. In addition,the free energies of activation for guanine in aqueous solution are all smaller than that for adenine,which predicts a preference of 1.9 kcal/mol when trans-[PtCl（H2O）（NH3）（pip）]＋ and trans-[Pt（H2O）2（NH3）（pip）]2＋ are the active agents and ～1.9 and ～ 5.3 kcal/mol when trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋ are the active agents,respectively. For the reaction of trans-Pt-chloroaqua （or diaqua） to cis-monoadduct,we obtain the same transition-state structure as from the reaction of trans-Pt-chloroaqua （or diaqua） to trans-monoadduct,which seems that the trans-Pt-chloroaqua （or diaqua） complex can generate trans-or cis-monoadduct via the same transition-state.
文摘To study new natural products, we used ODS （YMC, Kyoto, Japan） and silica gel column chromatography to separate compounds in Cercis chinensis Bunge （Leguminosae）. A new stilbene, trans- 3, 5, 3＇, 4＇-tetrahydroxy-4-methylstilbene （1）, along with 10 known compounds, namely piceatannol （2）, dihydromyricetin （3）, catechin （4）, dihydrorobinetin （5）, menisdaurin （6）, lithospermoside （7）, teatannin （8）, dasycarponin （9）, β-sitosterol （10）, and daucosterin （11）, was isolated from C. chinensis. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 2-6 and 9 were isolated from the genus Cercis Linn. for the first time.
