Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with...Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with an ionic liquid(IL)linkage via the one‐pot reaction of imidazole‐TsDPEN‐N‐Boc with 3‐(trimethoxysilyl)propyl bromide in the SBA‐15 mesopores.After coordination to Rh,the chiral solid catalysts could efficiently catalyze quinoline transfer hydrogenation,achieving 97%conversion with 93%ee,which was comparable to their homogeneous counterparts.The chiral solid catalyst with the IL linkage afforded much higher turnover frequency than that without the IL linkage(93 h^(–1)vs.33 h^(–1)),attributed to the phase transfer and formate‐enriching ability of the IL linkage.Furthermore,the effect of the pH on the reaction rate of the solid catalyst was investigated,preventing reaction rate retardation during the catalytic process.The tuning of the linkage group is an efficient approach for catalytic activity improvement of immobilized chiral catalysts.展开更多
A microporous luminescent metal-organic framework [Zn4L2(H2O)2]'(H2O)m(DMA)n (1) (H4L=5,5'-((1H-pyrazole-3,5-di- carbonyl)bis(azanediyl))diisophthalic acid, DMA=N,N-dimethylacetamide) was synthesized...A microporous luminescent metal-organic framework [Zn4L2(H2O)2]'(H2O)m(DMA)n (1) (H4L=5,5'-((1H-pyrazole-3,5-di- carbonyl)bis(azanediyl))diisophthalic acid, DMA=N,N-dimethylacetamide) was synthesized and characterized by infrared ra- diation (IR), thermogravimetric analyses (TGA), powder X-ray diffraction spectra (PXRD) and X-ray diffraction. Complex 1 has a three dimensional (3D) framework, which can be simplified as 5,5,5,5-c net with the Schlafi symbol of {43.64.83} {44.65.8 } {45.65 }2. This luminescent metal-organic framework (MOF) shows selectively sensitive to nitrobenzene and series of nitroaromatic explosives such as 4-nitrotoluene, 1,4-dinitrobenzene, 1,3-dinitrobenzene and 2,4-dinitrotoluene, and exhibits well recyclability. So complex 1 could be used to detect nitroaromatic explosives as a selective sensing material.展开更多
Various polysulfonamide (PSA) statistical copolymers were synthesized by polycondensation of three aromatic diamines and terephthaloyl chloride. The inherent viscosities of the resulting PSA copolymers range from 1....Various polysulfonamide (PSA) statistical copolymers were synthesized by polycondensation of three aromatic diamines and terephthaloyl chloride. The inherent viscosities of the resulting PSA copolymers range from 1.54 to 1.66 dL/g. The precipitated PSA copolymers with feed content of p-phenylene diamine (PPD) being less than 50% (mole fraction) can be redissolved in N-methyl-2-pryrrolidone (NMP) or N, N-dimethylacetamide (DMAc) with lithium chloride of WLiC1 : 0.02. All of the PSA copolymers exhibit enhanced tensile strength in comparison with PSA and still maintain excellent thermal stability in either air or nitrogen atmosphere展开更多
文摘Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with an ionic liquid(IL)linkage via the one‐pot reaction of imidazole‐TsDPEN‐N‐Boc with 3‐(trimethoxysilyl)propyl bromide in the SBA‐15 mesopores.After coordination to Rh,the chiral solid catalysts could efficiently catalyze quinoline transfer hydrogenation,achieving 97%conversion with 93%ee,which was comparable to their homogeneous counterparts.The chiral solid catalyst with the IL linkage afforded much higher turnover frequency than that without the IL linkage(93 h^(–1)vs.33 h^(–1)),attributed to the phase transfer and formate‐enriching ability of the IL linkage.Furthermore,the effect of the pH on the reaction rate of the solid catalyst was investigated,preventing reaction rate retardation during the catalytic process.The tuning of the linkage group is an efficient approach for catalytic activity improvement of immobilized chiral catalysts.
基金supported by the National Basic Research Program of China (2014CB845600)the National Natural Science of Foundation of China (21371102, 21421001)+1 种基金the MOE Innovation Team of China (IRT13022)the China Postdoctoral Science Foundation funded project (2015M571260)
文摘A microporous luminescent metal-organic framework [Zn4L2(H2O)2]'(H2O)m(DMA)n (1) (H4L=5,5'-((1H-pyrazole-3,5-di- carbonyl)bis(azanediyl))diisophthalic acid, DMA=N,N-dimethylacetamide) was synthesized and characterized by infrared ra- diation (IR), thermogravimetric analyses (TGA), powder X-ray diffraction spectra (PXRD) and X-ray diffraction. Complex 1 has a three dimensional (3D) framework, which can be simplified as 5,5,5,5-c net with the Schlafi symbol of {43.64.83} {44.65.8 } {45.65 }2. This luminescent metal-organic framework (MOF) shows selectively sensitive to nitrobenzene and series of nitroaromatic explosives such as 4-nitrotoluene, 1,4-dinitrobenzene, 1,3-dinitrobenzene and 2,4-dinitrotoluene, and exhibits well recyclability. So complex 1 could be used to detect nitroaromatic explosives as a selective sensing material.
基金the National Natural Science Foundation of China (No. 50973059)the Scientific Research Foundation of 2009 Graduate School of Shanghai University
文摘Various polysulfonamide (PSA) statistical copolymers were synthesized by polycondensation of three aromatic diamines and terephthaloyl chloride. The inherent viscosities of the resulting PSA copolymers range from 1.54 to 1.66 dL/g. The precipitated PSA copolymers with feed content of p-phenylene diamine (PPD) being less than 50% (mole fraction) can be redissolved in N-methyl-2-pryrrolidone (NMP) or N, N-dimethylacetamide (DMAc) with lithium chloride of WLiC1 : 0.02. All of the PSA copolymers exhibit enhanced tensile strength in comparison with PSA and still maintain excellent thermal stability in either air or nitrogen atmosphere