Polyethylene glycol (PEG) supported (diacetoxy)iodobenzene as soluble polymer reagent can smoothly oxidize acid hydrazides into corresponding dimmers in good yields under very mild conditions.
A mild, general, convenient, and efficient one-pot synthesis of 4-arylpyridines (4) is described using conventional heating, ultrasound and microwave irradiation. Aryl aldehydes (2) were efficiently condensed with eth...A mild, general, convenient, and efficient one-pot synthesis of 4-arylpyridines (4) is described using conventional heating, ultrasound and microwave irradiation. Aryl aldehydes (2) were efficiently condensed with ethylacetoacetate (1) and ammonium acetate in acetonitrile to give dihydropyridine intermediates (4). The latter underwent a smooth Iodobenzene Diacetate (III) mediated aromatization reaction in the same pot to afford 4-arylpyridines (4) in good to excellent yields.展开更多
The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-（4-quinoxalin- 2-yl-phenoxy）-tetrahydro-pyran-4-yl-ester 8 （C28H28N2O10, Mr = 552.54）, has been synthesized and its crystal structure was determined ...The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-（4-quinoxalin- 2-yl-phenoxy）-tetrahydro-pyran-4-yl-ester 8 （C28H28N2O10, Mr = 552.54）, has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060（8）, b = 5.648（4）, c = 24.11（2）A, β = 91.078（10）°, Z = 2, V= 1369.9（19）A^3, Dc = 1.339 g/cm^3,μ（MoKa） = 1.03 cm^-1, F（000） = 580.00, T =. 193.1 Kx-9 θmax = 25.03, （△/σ）max = 0.0000, Flack = -0.0（24）, the final R = 0.0680 and wR = 0.140 （w = 1/[0.0016Fo^2 ＋ 1.00000（Fo^2）]/（4Fo^2）） for 3126 observed reflections （1 〉 20（/））. The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.展开更多
The nanostructured mesoporous Pd/MCM-41 catalyst was prepared by impregnation.This catalyst exhibited high activity and selectivity to piphenyl during Ullmann coupling reaction of iodobenzene.With Pd loading of 12%,th...The nanostructured mesoporous Pd/MCM-41 catalyst was prepared by impregnation.This catalyst exhibited high activity and selectivity to piphenyl during Ullmann coupling reaction of iodobenzene.With Pd loading of 12%,the biphenyl yield may reach 50%,showing its good potential to match the homogeneous catalyst in traditional Ullmann coupling reactions.Based on BET and XRD etc.characterizations,the relationship between the excellent catalytic properties of the Pd/MCM-41 and its structural characteristics was discussed briefly.展开更多
基金We are grateful for the financial support from the Postdoctoral Foundation of China.
文摘Polyethylene glycol (PEG) supported (diacetoxy)iodobenzene as soluble polymer reagent can smoothly oxidize acid hydrazides into corresponding dimmers in good yields under very mild conditions.
文摘A mild, general, convenient, and efficient one-pot synthesis of 4-arylpyridines (4) is described using conventional heating, ultrasound and microwave irradiation. Aryl aldehydes (2) were efficiently condensed with ethylacetoacetate (1) and ammonium acetate in acetonitrile to give dihydropyridine intermediates (4). The latter underwent a smooth Iodobenzene Diacetate (III) mediated aromatization reaction in the same pot to afford 4-arylpyridines (4) in good to excellent yields.
基金This project was supported by the Key Laboratory of Organic Synthesis of Jiangsu Province
文摘The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-（4-quinoxalin- 2-yl-phenoxy）-tetrahydro-pyran-4-yl-ester 8 （C28H28N2O10, Mr = 552.54）, has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060（8）, b = 5.648（4）, c = 24.11（2）A, β = 91.078（10）°, Z = 2, V= 1369.9（19）A^3, Dc = 1.339 g/cm^3,μ（MoKa） = 1.03 cm^-1, F（000） = 580.00, T =. 193.1 Kx-9 θmax = 25.03, （△/σ）max = 0.0000, Flack = -0.0（24）, the final R = 0.0680 and wR = 0.140 （w = 1/[0.0016Fo^2 ＋ 1.00000（Fo^2）]/（4Fo^2）） for 3126 observed reflections （1 〉 20（/））. The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.
文摘The nanostructured mesoporous Pd/MCM-41 catalyst was prepared by impregnation.This catalyst exhibited high activity and selectivity to piphenyl during Ullmann coupling reaction of iodobenzene.With Pd loading of 12%,the biphenyl yield may reach 50%,showing its good potential to match the homogeneous catalyst in traditional Ullmann coupling reactions.Based on BET and XRD etc.characterizations,the relationship between the excellent catalytic properties of the Pd/MCM-41 and its structural characteristics was discussed briefly.
