Article
Chemistry, Organic
Chandan K. Mahato, Sayan Mukherjee, Mrinalkanti Kundu, Virbhadra P. Vallapure, Animesh Pramanik
Summary: This study utilized a new set of organic catalysts for asymmetric Michael reactions in water, achieving high efficiency and yield, offering a new method for green synthesis. The strategy also successfully synthesized an optically active octahydroindole, a key component found in many natural products.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Xiangjie Chen, Yi An, Guangfen Du, Yujie Zhao, Lin He, Jixing Zhao, Shi-Wu Li
Summary: This study established a method for asymmetric catalytic vinylogous Michael addition of 2-methyl-3,5-dinitrobenzoates to unsaturated ketones using chiral rhodium catalysts. This strategy successfully synthesized a variety of optically pure compounds containing imidazole and 3,5-dinitrobenzene skeletons.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Jae Ho Shim, Seok Hyun Cheun, Hyeon Soo Kim, Deok-Chan Ha
Summary: The study utilized thiourea as an organocatalyst to promote enantioselective Michael addition reaction between isobutyraldehydes and maleimides in water, achieving high yield and enantioselectivity. The solvent effect was explained by theoretical calculations suggesting the participation of a hydrogen bond activated CF3 substituent of the catalyst by surrounding water molecules, enabling low catalyst loading in organic reactions of chiral substances for pharmaceutical applications.
Article
Multidisciplinary Sciences
Hanwei Lu, Hebo Ye, Meilan Zhang, Zimu Liu, Hanxun Zou, Lei You
Summary: Phototriggered click and clip reactions can achieve high spatiotemporal resolution and sustainability in chemical processes, and this study reports a photoswitchable reversible covalent conjugate addition-elimination reaction with a broad scope. By coupling a photochromic dithienylethene switch with Michael acceptors, the reactivity of Michael reactions can be controlled, allowing the dynamic exchange of various nucleophiles. The authors demonstrate the versatile applications of this reaction, including light-mediated surface modification, regulation of amphiphilic assemblies, and creation/degradation of covalent polymers on demand.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Analytical
Liangping Tu, Jian Liu, Zichang Zhang, Qingrong Qi, Shun Yao, Wencai Huang
Summary: The newly developed Hcy-DCV probe can quickly and efficiently detect malononitrile, showing good selectivity and water solubility with a detection limit of 6.92 ppb. In addition, the probe demonstrates good recovery rate and relative standard deviation in practical applications in pure water, and can visualize malononitrile detection through probe-coated strip papers.
Article
Engineering, Chemical
Yiying Pang, Bowei Wang, Yazhuo Kang, Jiayi Li, Xiaoyi Gu, Guoqiang Kang, Xilong Yan, Yang Li, Ligong Chen
Summary: In this study, a sulfonated chiral covalent organic framework (SDA-CCOF) was successfully synthesized and used as a catalyst for the asymmetric Michael addition reaction of acetone with nitrostyrene. The catalyst exhibited good catalytic performance with a high enantioselectivity of 90%. It also demonstrated high enantioselectivity for diverse substrates.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Chemistry, Organic
Jianli Zheng, Yingqian Xu, Shaorui Song, Ling Huang, Dongdong Cao, Aiguo Zhong, Jianguo Yang, Dingben Chen
Summary: The photoredox-catalyzed 1,6-difluoromethylation of 3-methyl-4-nitro-5-styrylisoxazole with HCF2SO2Na has been developed, yielding structurally diverse difluoromethylated products. The di-, tri-, and monofluoromethylation were compared, showing the highest yield for difluoromethylation. DFT calculations revealed the nucleophilicity of CF2H radical and the lowest transition state activation energy in the difluoromethylation reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Green & Sustainable Science & Technology
Ashutosh Bahuguna, Vishal Kumar, Srinivasan Ramalingam, Anil Kumar Yadav, Myunghee Kim
Summary: Ginger was found to effectively reduce aflatoxins and protect cells from toxicity.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Chemistry, Multidisciplinary
Daisuke Yamauchi, Ikumi Nakamura, Takahiro Nishimura
Summary: The Ir-catalyzed enantioselective addition of an N-methyl C-H bond of 2-(methylamino)pyridine derivatives to alpha-trifluoromethylstyrenes proceeded via C-H activation to give chiral gamma-branched amine derivatives having a trifluoromethyl-substituted stereocenter. It was found that a bulky and electron-withdrawing group at the 3-position of 2-(methylamino)pyridines was necessary for the present C-H addition reaction catalyzed by a cationic iridium/chiral bisphosphine complex.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Kiran Kumari, Meeta Bhati, Roopendra Singh Madhukar, Akram Gulam Hussain Khan, Prachi Janjani, S. Rajagopala Reddy, Srinivasan Easwar
Summary: A sulfonamide moiety was introduced at the C-4 position of proline, cis to the -COOH group, to investigate a possible synergistic interaction between the two functional groups and its consequent influence on the enamine mediated asymmetric aldol reaction. The results demonstrate that the resulting catalyst is capable of efficiently producing aldol adducts with excellent diastereo- and enantioselectivities in the presence of water.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Kiran Kumari, Meeta Bhati, Roopendra Singh Madhukar, Akram Gulam Hussain Khan, Prachi Janjani, S. Rajagopala Reddy, Srinivasan Easwar
Summary: A sulfonamide moiety was introduced at the C-4 position of proline, cis to the -COOH group, to investigate the potential synergistic interaction between the two functional groups and its influence on the enamine mediated asymmetric aldol reaction. The resulting catalyst exhibited high efficiency in producing aldol adducts with excellent diastereo- and enantioselectivities in the presence of water. Computational study was also conducted to gain further insights into the proposed cooperative assistance.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Jiaming Wang, Jia Li, Changgui Zhao
Summary: A Lewis acid-promoted annulation method for the synthesis of nitrogen-containing medium-sized rings from azadienes and cyclobutamines has been developed. This reaction involves a cascade of Michael addition and ring-expansion, giving moderate to high yields and a broad scope of products. The use of a chiral base has also been explored for the catalytic asymmetric version of this reaction.
Article
Materials Science, Multidisciplinary
Niklas Huber, Masis Sirim, Zhuangfei Qian, Calum T. J. Ferguson, Wenxin Wei, Kai A. I. Zhang
Summary: The use of polymeric photocatalytic materials for the visible light driven conversion of organic substances in environmentally friendly reaction media, especially in water, has attracted much attention recently. However, most current conjugated polymer photocatalysts are not suitable for applications in water due to their hydrophobic nature. In this study, water-compatible poly(methyl methacrylate) (PMMA)-based polymer photocatalysts were designed by controlling the comonomers with specific functions. The properties and water compatibility of PMMA photocatalysts could be tuned by the monomer composition. The photocatalytic degradation of various contaminants in water was successfully conducted using the PMMA photocatalysts.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Metallurgy & Metallurgical Engineering
Yimeng Xu, Bicheng Deng, Shengting Kuang, Wuping Liao
Summary: A new aminophosphonate extractant, di(2-ethylhexyl) (N, N'-di(2-ethylhexyl) amino methyl) phosphonate (L), was synthesized and used for the extraction and separation of gallium and indium from chloride solution. The maximum separation factors SFGa/In reached 995, higher than those of its analogues Cextrant 230 (SFGa/In = 471) and BEADP (SFGa/In = 201) under optimal acidity conditions. The extracted complexes were identified as HGaCl4L2 and InCl3L2. The extraction reactions of gallium and indium were both endothermic. The loading capacities of 30 vol% L for Ga and In were 32.9 g/L and 25.2 g/L, respectively. Gallium and indium loaded in the organic phase can be effectively stripped by distilled water, H2SO4, and HNO3. A process was developed for the separation and purification of gallium, with Ga2O3 purity increasing from 98.4% to 99.97% and a yield of 92.5%.
Article
Chemistry, Organic
Zhuang Ni, Ran Sun, Jihong Wu, Chao Xu, Jinwen Huang, Fanhong Wu
Summary: The novel indium-mediated difluoroalkylation of iododifluoromethyl ketones with alpha, beta-unsaturated ketones provides a significant route to access 1,2-addition product with excellent regioselectivity. This method has a wide substrate scope, high efficiency, and mild reaction conditions. Furthermore, it can be applied to the synthesis of difluoro derivatives of biologically active molecules containing unsaturated ketone structures, serving as potentially valuable fluorinated intermediates in drug discovery.
