A novel acrylic monomer bearing aromatic ethereality group N-(p -phenoxy-phenyl) methacrylamide(MAPOA) was synthesized and polymerized. The fluorescence spectra of MAPOA and its polymer were studied, showing that the ...A novel acrylic monomer bearing aromatic ethereality group N-(p -phenoxy-phenyl) methacrylamide(MAPOA) was synthesized and polymerized. The fluorescence spectra of MAPOA and its polymer were studied, showing that the polymer displays a stronger fluorescence than its monomer at the same chromophore concentration. The fluorescence of P(MAPOA) was quenched by adding electron deficiency monomers such as MMA, AN etc .. It is another example of showing the 'fluorescence structural self-quenching effect' as we reported previously, from which it is demonstrated again that this phenomenon is not an accidental one but a common effect for acrylic monomers bearing electon-donating chromophores. The photopolymerization of AN sensitized by MAPOA and P(MAPOA) was studied. The kinetic equation of the polymerization was obtained and represented as follows: R _p∝ 0.38 × 0.78 , R _p∝ 0.33 × 0.71 The overall activation energies were determined to be E_ a =24\^22 kJ/mol(MAPOA) and E_ a =26\^31 kJ/mol respectively. The fluorescence analysis of the resulted P(AN) showed that the sensitizer also entered into the P(AN) chains. A mechanism of the formation of a charge transfer complex and free radical initiation was suggested for the photopolymerization of AN sensitized by MAPOA and P(MAPOA).展开更多
Iminodiacetic acid resin-chelated copper(Ⅱ) complex is effective in cross-coupling reactions between azaheterocycles and aryl or heteroaryl halides,providing N-arylated products in good to excellent yields.The copper...Iminodiacetic acid resin-chelated copper(Ⅱ) complex is effective in cross-coupling reactions between azaheterocycles and aryl or heteroaryl halides,providing N-arylated products in good to excellent yields.The copper catalyst is air stable and can be readily recovered and reused with minimal loss of activity for three runs.展开更多
Ma＇s CuI/proline procedure for the catalytic cross coupling between nitrogen heterocycles and aryl halides was markedly improved. The key finding was that K3PO4 was a much better base than K2CO3 for the reaction. Wit...Ma＇s CuI/proline procedure for the catalytic cross coupling between nitrogen heterocycles and aryl halides was markedly improved. The key finding was that K3PO4 was a much better base than K2CO3 for the reaction. With this new reaction condition the cross coupling with aryl iodides could be accomplished in 1,4-dioxane instead of DMSO. This reactin also could be carried out in DMF. Furthermore, the coupling yields under the new conditions are usually higher than in Ma＇s original methods.展开更多
A bifunctional heterogeneous catalyst was designed and synthesized,denoted DMEDA/IL–NH2-MIL-101.The structure and physical-chemical characterization of DMEDA/IL–NH2-MIL-101 and its precursors were characterized by S...A bifunctional heterogeneous catalyst was designed and synthesized,denoted DMEDA/IL–NH2-MIL-101.The structure and physical-chemical characterization of DMEDA/IL–NH2-MIL-101 and its precursors were characterized by SEM,N2 adsorption-desorption,XPS,FT-IR,PXRD,elemental analysis,and TGA techniques.The date showed that the two catalytic components of N,N-dimethylethylenediamine(DMEDA)and 1-butyl-3-methylimidazolium bromide(BmimBr)were chemically immobilized in NH2-MIL-101 nanocages.The amine of DMEDA was grafted onto carrier NH2-MIL-101 by N–Cr coordinate covalent bonds and the ionic liquid of BmimBr(IL(Br-))was anchored in the NH2-MIL-101 nanocages by'ship-in-a-bottle'method,in which the amidogen of NH2-MIL-101 condensed with N,N-carbonyldiimidazole(CDI)firstly,and then alkylated with 1-bromo butane.This novel heterogeneous catalyst with two different active sites can efficiently catalyze the synthesis of N-aryl oxazolidin-2-ones from carbon dioxide(CO2),epoxides,and anilines in one-pot under mild solvent-free conditions.It not only showed good stability and recoverability after five cycles but also exhibited shape selectivity for the substrate due to the synergic catalysis of amine,ionic liquid,and NH2-MIL-101.This novel bifunctional material is a promising solid catalyst for the green synthesis of N-aryl oxazolidin-2-ones.展开更多
Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and wer...Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and were identified to be Cu（0） and Cu（Ⅰ） in XRD patterns. Excellent catalytic activity and selectivity were achieved in the N-arylation of pyrazole under ligand and protection gas free conditions. About90.4% of product yield was achieved with only 0.5 mol% of copper catalyst（Cu-C-300）, which was considerably more efficient than previous reports. XPS results suggested that the N-arylation of pyrazole activity was closely related to the surface Cu（Ⅰ） species.展开更多
At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional...At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.展开更多
Herein,we report rhodium catalyzed N-arylation via addition of arylboronic acids to electron-deficientα-iminoesters which can be prepared in high efficiency by using easily accessible B-carbonyl esters.The reaction i...Herein,we report rhodium catalyzed N-arylation via addition of arylboronic acids to electron-deficientα-iminoesters which can be prepared in high efficiency by using easily accessible B-carbonyl esters.The reaction is highly regiospecific to achieve the N-aryl addition efficiently with up to 99%yield under mild conditions.The corresponding product can be further efficiently converted into indoles andaseries of other important building blocks.展开更多
N-(p-hydroxyphenyl)methacrylamide was successfully synthesized(yield 86%) by the reaction of methacryloyl chloride with p-aminophenol.The separating and purifying methods of the product was discussed,and the influenci...N-(p-hydroxyphenyl)methacrylamide was successfully synthesized(yield 86%) by the reaction of methacryloyl chloride with p-aminophenol.The separating and purifying methods of the product was discussed,and the influencing factors on the synthesis were simply explored.The aim product was characterized and verified by FT-IR,1H NMR,MS spectra and elemental analysis.展开更多
文摘A novel acrylic monomer bearing aromatic ethereality group N-(p -phenoxy-phenyl) methacrylamide(MAPOA) was synthesized and polymerized. The fluorescence spectra of MAPOA and its polymer were studied, showing that the polymer displays a stronger fluorescence than its monomer at the same chromophore concentration. The fluorescence of P(MAPOA) was quenched by adding electron deficiency monomers such as MMA, AN etc .. It is another example of showing the 'fluorescence structural self-quenching effect' as we reported previously, from which it is demonstrated again that this phenomenon is not an accidental one but a common effect for acrylic monomers bearing electon-donating chromophores. The photopolymerization of AN sensitized by MAPOA and P(MAPOA) was studied. The kinetic equation of the polymerization was obtained and represented as follows: R _p∝ 0.38 × 0.78 , R _p∝ 0.33 × 0.71 The overall activation energies were determined to be E_ a =24\^22 kJ/mol(MAPOA) and E_ a =26\^31 kJ/mol respectively. The fluorescence analysis of the resulted P(AN) showed that the sensitizer also entered into the P(AN) chains. A mechanism of the formation of a charge transfer complex and free radical initiation was suggested for the photopolymerization of AN sensitized by MAPOA and P(MAPOA).
基金supported by the Natural Science Foundation of Zhejiang Province(No.Y407240).
文摘Iminodiacetic acid resin-chelated copper(Ⅱ) complex is effective in cross-coupling reactions between azaheterocycles and aryl or heteroaryl halides,providing N-arylated products in good to excellent yields.The copper catalyst is air stable and can be readily recovered and reused with minimal loss of activity for three runs.
文摘Ma＇s CuI/proline procedure for the catalytic cross coupling between nitrogen heterocycles and aryl halides was markedly improved. The key finding was that K3PO4 was a much better base than K2CO3 for the reaction. With this new reaction condition the cross coupling with aryl iodides could be accomplished in 1,4-dioxane instead of DMSO. This reactin also could be carried out in DMF. Furthermore, the coupling yields under the new conditions are usually higher than in Ma＇s original methods.
基金Support of this work by the National Natural Science Foundation of China(21573016)is gratefully acknowledged.
文摘A bifunctional heterogeneous catalyst was designed and synthesized,denoted DMEDA/IL–NH2-MIL-101.The structure and physical-chemical characterization of DMEDA/IL–NH2-MIL-101 and its precursors were characterized by SEM,N2 adsorption-desorption,XPS,FT-IR,PXRD,elemental analysis,and TGA techniques.The date showed that the two catalytic components of N,N-dimethylethylenediamine(DMEDA)and 1-butyl-3-methylimidazolium bromide(BmimBr)were chemically immobilized in NH2-MIL-101 nanocages.The amine of DMEDA was grafted onto carrier NH2-MIL-101 by N–Cr coordinate covalent bonds and the ionic liquid of BmimBr(IL(Br-))was anchored in the NH2-MIL-101 nanocages by'ship-in-a-bottle'method,in which the amidogen of NH2-MIL-101 condensed with N,N-carbonyldiimidazole(CDI)firstly,and then alkylated with 1-bromo butane.This novel heterogeneous catalyst with two different active sites can efficiently catalyze the synthesis of N-aryl oxazolidin-2-ones from carbon dioxide(CO2),epoxides,and anilines in one-pot under mild solvent-free conditions.It not only showed good stability and recoverability after five cycles but also exhibited shape selectivity for the substrate due to the synergic catalysis of amine,ionic liquid,and NH2-MIL-101.This novel bifunctional material is a promising solid catalyst for the green synthesis of N-aryl oxazolidin-2-ones.
基金supported by the Natural Science Foundation of China(91645115 and 21473003)High-level talents funding project of Hebei(CL201601,E2016100015)science technology research and development guidance program project of Baoding City(No.16ZF027)
文摘Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and were identified to be Cu（0） and Cu（Ⅰ） in XRD patterns. Excellent catalytic activity and selectivity were achieved in the N-arylation of pyrazole under ligand and protection gas free conditions. About90.4% of product yield was achieved with only 0.5 mol% of copper catalyst（Cu-C-300）, which was considerably more efficient than previous reports. XPS results suggested that the N-arylation of pyrazole activity was closely related to the surface Cu（Ⅰ） species.
基金supported by the National Natural Science Foundation of China(No.81171731)the Project of Chengdu Science and Technology Bureau(Nos.2021-YF05-01619-SN and 2021-RC05-00022-CG)+2 种基金the Science and Technology Project of Tibet Autonomous Region(Nos.XZ202202YD0013C and XZ201901-GB-08)the Sichuan Science and Technology Program(No.2022YFG0066)the 1·3·5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(Nos.ZYJC21026,ZYGD21001 and ZYJC21077).
文摘At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.
基金financial support from the Natural Science Foundation of Shanghai(20zR1405500).
文摘Herein,we report rhodium catalyzed N-arylation via addition of arylboronic acids to electron-deficientα-iminoesters which can be prepared in high efficiency by using easily accessible B-carbonyl esters.The reaction is highly regiospecific to achieve the N-aryl addition efficiently with up to 99%yield under mild conditions.The corresponding product can be further efficiently converted into indoles andaseries of other important building blocks.
文摘N-(p-hydroxyphenyl)methacrylamide was successfully synthesized(yield 86%) by the reaction of methacryloyl chloride with p-aminophenol.The separating and purifying methods of the product was discussed,and the influencing factors on the synthesis were simply explored.The aim product was characterized and verified by FT-IR,1H NMR,MS spectra and elemental analysis.
