JOURNAL OF ORGANIC CHEMISTRY
·
2022
·
IF 4.198
Zhaohang Chen,Pengcheng Zhou,Yuanxia Guo,Anna,Jiakun Bai,Renzhong Qiao,Chao Li
A guanosine-based hydrogel formed by the self-assembly of guanosine and 4-((l-prolinamide)methyl)phenylboronic acid was constructed. The G quartets were selectively stabilized by K+ ions to form a self-supporting transparent hydrogel. These guanosine-derived assemblies were used to catalyze the aldol reaction in water without any additives, affording desirable conversion and enantioselectivity of the product. The controlled assays of small-molecule components indicated that the stable assemblies were the definite species that achieved high enantioselective catalysis. The current catalytic system can be readily recovered by simple extraction and still acquired good performance of the reaction after four cycles.
研究领域:
生物化学
·
材料科学
·
有机化学
✓ 已验证
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Lijia Liu,Yaodong Wang,Fuqingyun Wang,Chunhong Zhang,Yanli Zhou,Zhengjin Zhou,Xudong Liu,Ruiqi Zhu,Hongxing Dong,Toshifumi Satoh
One-handed helical substituted polyacetylene has received extensive attention due to its potential in chiral stationary phases and molecular recognition . Here, three one-handed helical poly(phenylacetylene)s bearing proline or proline dipeptide as the pendants ( PPA-Pro, PPA-Pro-Pro and PPA-Pro-Hyp ) were synthesized. As the catalyst, the three helical polymers separately catalyzed the asymmetric aldol reaction of acetone with p -nitrobenzaldehyde in a various media. The results indicate that PPA-Pro-Pro and PPA-Pro-Hyp bearing dipeptide pendants showed the higher catalytic activity and enantioselectivity than the PPA-Pro bearing proline pendants and the corresponding monomer catalysts. This indicates the synergistic effect of the dipeptide pendants with the one-handed helical mainchain of the polymer catalyst. The polymer catalysts can be recycled and maintain the catalytic performance after four circles. When imidazole was added to the reaction system, the reaction yield could be efficiently improved without affecting the enantioselectivity.
研究领域:
有机化学
·
高分子化学
·
催化化学
✓ 已验证
DOI
高影响因子
NANO
·
2020
·
IF 1.566
Lijuan Liu,Jiachen Yan,Chan Zheng,Rong Xiao,Pingqiang Dai,Qianting Wang,Wei Li,Wenzhe Chen
Organic pollutants in water pose a serious risk to public health, hence, it is essential to develop new and innovative approaches to the remediation of contaminated water. This work demonstrates a highly effective bubble-propelled micromotor based on the surface coating of symmetrical carbon microspheres (CMSs) with catalytic manganese dioxide (MnO 2 ) nanoflakes and platinum nanoparticles (Pt NPs) (Pt-MnO 2 @CMS). This concept represents a simple and flexible strategy for the decomposition of organic pollutants in water and could be used to construct a wide range of diverse micromotors with applications in drug delivery, sensing, energy generation and environmental remediation. The unique hierarchical structure of the MnO 2 nanoflakes and the uniform dispersion of Pt NPs in this material were confirmed. The resulting micromotors were found to move rapidly as a result of propulsion by oxygen bubbles generated in a H 2 O 2 solution via the catalytic actions of the MnO 2 nanoflakes and Pt NPs. In contrast to the intrinsic asymmetry of tubular and Janus structures, the self-driven motion of these symmetrical micromotors can be attributed to morphological variations and the uneven distribution of the cocatalysts. Combining a porous structure, rapid movement and Fenton-like reactions, these Pt-MnO 2 @CMS micromotors rapidly degraded methylene blue (MB), providing greater than 99% decolorization in just 30 min without the need for external agitation. Analyses of the adsorption mechanism based on pseudo-first-order and pseudo-second-order kinetics models showed that adsorption proceeded via chemical processes. These new micromotors are expected to have important environmental and biomedical applications.
研究领域:
环境科学
·
纳米技术
·
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2017
·Vol. 10
·期 5
·1166-1172
·
IF 4.803
Lan-Lan Lou,Huaxin Qu,Wenjun Yu,Bei Wang,Lezi Ouyang,Shuangxi Liu,Wuzong Zhou
Graphical Thermoresponsive lipase catalyst : A UCST-type thermoresponsive polymer–lipase conjugate was exploited and applied as an asymmetric biocatalyst in the kinetic resolution of racemic α-methylbenzyl butyrate, exhibiting high catalytic performance, easy recovery, and good durability. A thermoresponsive lipase catalyst with an upper critical solution temperature (UCST) of about 26 °C was exploited by covalent immobilization of an enzyme, Pseudomonas cepacia lipase (PSL), onto poly(acrylamide- co -acrylonitrile) by glutaraldehyde coupling. The experimental conditions for the PSL immobilization were optimized. The immobilized PSL was much more stable for wide ranges of temperature and pH than free PSL. The material was also evaluated as an asymmetric catalyst in the kinetic resolution of racemic α-methylbenzyl butyrate at 55 °C in an aqueous medium and exhibited high catalytic performance and stability. Up to 50 % conversion and 99.5 % product enantiomeric excess were achieved, thus providing highly pure enantiomers. This biocatalyst could be easily recovered by simple decantation for reuse based on temperature-induced precipitation. It showed good reusability and retained 80.5 % of its original activity with a well reserved enantioselectivity in the 6th cycle. This work would shed light on the future development of new UCST-type enzyme catalysts.
研究领域:
生物化学
·
酶工程
·
材料科学
✓ 已验证
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2017
·Vol. 35
·期 1
·1700280
·
IF 4.474
Yin Zhang,Yanfei Zhu,Wencai Zhou,Xueying Qiu,Zhiyong Tang
To find cheap and commercially available materials that are efficient in the catalytic process is of paramount importance for practical application in both chemical and biomedical engineering. As-purchased nanosized semiconductors are systematically investigated as catalysts in visible light driven asymmetric reactions with the help of chiral ligands. Significantly, among varied semiconductors, WO 3 exhibits the best performance with 91% enantiomeric excess and 95% conversion ratio.
研究领域:
化学工程
·
生物医学工程
·
材料科学
·
催化
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2021
·
IF 8.271
Yiqi Ren,Lin Tao,Chunzhi Li,Sanjeevi Jayakumar,He Li,Qihua Yang
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 immo-bilization of TsDPEN on SBA-15 with an ionic liquid (IL) linkage via the one-pot reac-tion 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 cata-lyze 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 in-vestigated, 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.
研究领域:
化学
·
催化科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 33
·21574-21581
·
IF 4.036
Junfeng Zhu,Xiaorong Meng,Wen Liu,Yabing Qi,Siyi Jin,Shanshan Huo
We present an efficient and easy synthesis method for incorporating organocatalytic moieties into Zr-metal organic frameworks (Zr-MOFs). The catalytic activity and selectivity of the new chiral catalysts were improved by adjusting the aperture of the MOF cavities. The hole size of the Zr-MOF was modulated by adding acid and replacing bridge ligands during synthesis. The difunctional chiral units of amino acid–thiourea are anchored onto the Zr-MOF by a mild synthesis method from an isothiocyanate intermediate which could effectively avoid the racemization of chiral moieties in the synthesis process. By means of specific surface area measurement (BET), scanning electron microscopy (SEM) and powder X-ray Diffraction (PXRD), it was confirmed that Zr-MOFs with different pore sizes were synthesized without breaking the basic octahedral structure of the MOF. Finally, good yields (up to 83%) and ee values (up to 73%) were achieved with the new heterogeneous catalysts in 48 hours for the aldol reaction of 4-nitrobenzaldehyde with acetone. By contrast, using the catalyst support without modulating the synthesis, the yield (30%) and the ee-value (26%) were both low. Experiments have confirmed the important influence on the reaction selectivity of providing a suitable reaction environment by controlling the aperture of MOF cavities.
研究领域:
材料化学
·
有机合成
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of the American Chemical Society
·
2022
·
IF 16.383
Wenge Zhang,Pei-Chao Zhang,Yin-Lin Li,Hai-Hong Wu,Junliang Zhang
Asymmetric cycloaddition reactions are the most powerful tool to the expeditious construction of enantioenriched cyclic motifs in organic chemistry. In sharp contrast to well-developed cycloaddition reactions via the palladium-trimethylenemethane (Pd-TMM) intermediate, hetero (3 + 2) cycloadditions of the heteroallyl cations remain rare, largely due to their thermally forbidden nature. To the best of our knowledge, there is no example of asymmetric version leading to enantioenriched heterocycles reported so far. Herein we enabled the first example of catalytic asymmetric (3 + 2) cycloaddition of electrophilic palladium-heteroallyl zwitterion intermediate (Pd-OTMM or Pd-NTMM) with cyclic or acyclic 1,3-dienes via a pathway terminated with C–N or C–O bond formation, delivering the highly substituted or fused pyrrolidine and tetrahydrofuran rings in high yields with excellent regio-, diastereo-, and enantioselectivity. Engineering the PC-Phos, one of the chiral sulfinamide phosphine (Sadphos) type ligands, by introducing the di-tert-butyl or/and 3,5-difluorophenyl group is a vital component in achieving excellent catalytic reactivity and enantioselectivity.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）