Article
Chemistry, Organic
Steeva Sunny, Mohit Maingle, Kapileswar Seth
Summary: The application of bifunctional organocatalysts, specifically squaramides, in organic chemistry has significantly advanced due to their stability, low toxicity, ease of handling, and recoverability. This review article provides a comprehensive report on the fine-tunable bifunctional chiral squaramide-catalyzed sulfa-Michael addition, emphasizing the construction of complex molecular entities with multiple stereocenters. The article also summarizes the progress made in chiral squaramide-catalyzed asymmetric sulfa-Michael addition and subsequent cascade reactions between 2011 and 2022.
Article
Chemistry, Multidisciplinary
Xiongfei Deng, Shiqi Zhang, Hesen Huang, Xin Cui, Zhuo Tang, Guangxun Li
Summary: Highly enantioselective sulfa-Michael additions between 2-alkenyl quinoxalines and aromatic thiols were achieved using a low loading of chiral phosphoric acid catalyst. The investigation revealed that the two C = N units of quinoxalines are essential for controlling the enantioselectivities. Substituted non-terminal 2-alkenes with aryls or alkyls, and even other electro-withdrawing groups like ketones, esters, or amides, selectively reacted and yielded the desired products with good regioselectivities, high yields, and good ee values.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Organic
Shuting Tan, Jian-Guo Liu, Ming-Hua Xu
Summary: A rhodium-catalyzed asymmetric 1,4-addition reaction provides a practical approach for synthesizing highly enantioenriched chiral N-alkylindoles.
Review
Chemistry, Multidisciplinary
Cheng Niu, Da-Ming Du
Summary: This review highlights the recent advancements in sulfa-Michael addition-triggered cascade reactions for the stereoselective synthesis of sulfur-containing compounds. It discusses various types of reactions, including sulfa-Michael/aldol, sulfa-Michael/Henry, sulfa-Michael/Michael, sulfa-Michael/Mannich and some sulfa-Michael triggered multi-step processes. The review also introduces reaction mechanisms and derivatization experiments.
Article
Chemistry, Organic
Ye Zhang, Jingcheng Guo, Jinna Han, Xiangui Zhou, Wei Cao, Zhenqian Fu
Summary: The bifunctional squaramide-catalyzed nucleophilic addition of thiophenols to easily available beta-silyl alpha,beta-unsaturated carbonyl compounds has been successfully developed, leading to the efficient preparation of a structurally diverse set of chiral alpha-mercaptosilanes with good to excellent yields and acceptable enantioselectivities. The reaction features mild reaction conditions, a broad substrate scope, and easy scale-up.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Daniel Rozsar, Michele Formica, Ken Yamazaki, Trevor A. Hamlin, Darren J. Dixon
Summary: This paper describes a metal-free catalytic intermolecular enantioselective Michael addition to unactivated alpha,beta-unsaturated amides. Consistently high enantiomeric excesses and yields were obtained under mild reaction conditions, using a novel squaramide-based bifunctional iminophosphorane catalyst. Computational analysis revealed the origin of the high enantiofacial selectivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Zara M. Seibel, Jeffrey S. Bandar, Tristan H. Lambert
Summary: The enantioselective synthesis of alpha-substituted glutamates and pyroglutamates via a cyclopropenimine-catalyzed Michael addition of amino ester imines has been described, achieving enantioselectivities of up to 94% and compatibility with various functional groups. The impact of catalyst structure and imine substitution was discussed, highlighting a broader and more enantioselective access to pyroglutamate derivatives compared to other methods.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Mingxia Ye, Yingying Xu, Tianhang Song, Zhenbo Gao
Summary: A novel NbCl5-catalyzed sulfa-conjugate addition has been developed for constructing quaternary centers in various enones, providing a new pathway to add thiols to tri-substituted enones. This method allows a range of functionalized thiols to access different β-sulfido carbonyl compounds, leading to the synthesis of 27 novel β-sulfido ketones with moderate to excellent yields. The mechanism of this reaction has also been studied using DFT calculations.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Applied
Yabo Deng, Shuo Sun, Yuqiang Wang, Pengfeng Jia, Wenguang Li, Kairong Wang, Wenjin Yan
Summary: A novel domino reaction has been disclosed utilizing quinidine-derived ammonium salts as a phase transfer catalyst, facilitating the efficient synthesis of a range of CF2H-containing spirofindoline-3,3'-thiophenels under mild conditions. The reaction resulted in high yields, excellent diastereoselectivities, and good enantioselectivities in short reaction times.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Yi Xiao, Yangyang Jiang, Chao Xu, Pratanphorn Nakliang, Sanghee Yoon, Sun Choi, Yian Guo, Tao Ye
Summary: The stereocontrolled total synthesis of the antitumor natural product thioamycolamide A has been achieved in 14 steps with an overall yield of 19.1%. The key aspect of our approach is the preparation of the beta-alkylthio amide subunit through an auxiliary-controlled, diastereoselective sulfa-Michael addition.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Multidisciplinary Sciences
Chayanid Ongpipattanakul, Shi Liu, Youran Luo, Satish K. Nair, Wilfred A. van der Donk
Summary: The addition of Cys to dehydroalanine (Dha) and dehy-drobutyrine (Dhb) in both eukarya and bacteria plays important roles in various biological processes. In bacteria, this addition is catalyzed by lanthipeptide cyclases (LanC) proteins to produce lanthipeptides. In eukarya, the addition of Cys in glutathione to Dha/Dhb is catalyzed by eukaryotic LanC-like (LanCL) enzymes to protect cellular proteome. The crystal structures of human LanCL1 enzyme complexed with different ligands reveal the mechanism of the enzyme-catalyzed thia-Michael addition involving zinc ion activation, protonation of enolate intermediate, and stabilization of negative charge.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Medicinal
Alime Ebru Aydin, Selda Culha
Summary: The synthesis of chiral squaramide catalysts (8-15) and their catalytic efficiency in the enantioselective conjugate addition of pyrazolones to nitroalkenes were described, providing excellent chemical yields (up to 93%) of chiral 5-methyl-4-(2-nitro-1-arylethyl)pyrazol-3-ol derivatives with high enantioselectivities (up to 97% ee).
Article
Chemistry, Organic
Shi-Jie Zhu, Zhi-Feng Hao, Ya Pan, Ying Zhou, Xiong-Li Liu, Ming Zhang, Chuan-Wen Lei
Summary: In this study, a stepwise enantioselective formal (3 + 2) cyclocondensation reaction was successfully accomplished, leading to the synthesis of spiro-fused pentacyclic spirooxindoles. The reaction showed good overall yields, excellent dr, and high ee values.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Shi-Jie Zhu, Zhi-Feng Hao, Ya Pan, Ying Zhou, Xiong-Li Liu, Ming Zhang, Chuan-Wen Lei
Summary: The first enantioselective formal (3 + 2) cyclocondensation involving alpha,fi-unsaturated pyrazoleamides as 3-carbon partners was successfully achieved in a stepwise fashion. The protocol led to the synthesis of spiro-fused pentacyclic spirooxindoles with good overall yields, excellent diastereomeric ratios, and high enantiomeric excess values.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Xuelun Duan, Nan Zheng, Gongbo Liu, Ming Li, Qiming Wu, Xinhao Sun, Wangze Song
Summary: A novel four-component reaction has been developed for the efficient synthesis of polyfunctionalized triazoles. This reaction involves the formation of four C-N bonds in one step under mild conditions, using alkynes, amines, azides, and 2H-azirines as reactants.
Article
Chemistry, Multidisciplinary
Alexander M. Prophet, Kritanjan Polley, Gary J. Van Berkel, David T. Limmer, Kevin R. Wilson
Summary: The oxidation kinetics of iodide by ozone at the air-water interface is studied in single microdroplets. Molecular simulations and kinetic modeling are used to understand the underlying multiphase mechanism.
Article
Chemistry, Multidisciplinary
Rong Zhang, Jiajing Lan, Fei Wang, Shumei Chen, Jian Zhang
Summary: By utilizing 1,1'-ferrocene dicarboxylic acid as a chelating and surface protection ligand, we have synthesized multi-nuclear indium oxide clusters with varying nuclear sizes, including heptanuclear and thirteen-nuclear clusters. These clusters possess labile coordination sites, allowing for structural modification and self-assembly, resulting in the formation of various cluster structures.
Article
Chemistry, Multidisciplinary
Hui Wang, Hui Liu, Mingsen Wang, Jiaheng Hou, Yongjun Li, Yuancheng Wang, Yingjie Zhao
Summary: Two supramolecular complexes were prepared using CBs and M1, and their single-crystal structures were analyzed by SCXRD. The unexpected 1:2 self-assembly structure between M1 and CB[8] was discovered for the first time. These complexes exhibit unique photophysical properties and provide valuable information about the structure and photophysical properties of supramolecular complexes.
Article
Chemistry, Multidisciplinary
Chang-Hee Lee, Sookil Park, Sanggil Kim, Ji Young Hyun, Hyun Soo Lee, Injae Shin
Summary: The epidermal growth factor receptor (EGFR) is a cell-surface glycoprotein involved in cell proliferation and tumor development. This study used a fluorescently labeled EGFR to investigate its time-dependent endocytosis in live cells and found that appended glycans affect EGFR internalization. Additionally, the study detected sialic acid residues attached to EGFR on the live cell surface using FRET-based imaging. This research provides valuable insights into the cellular functions of EGFR.
Article
Chemistry, Multidisciplinary
Subhankar Sahu, Lokesh Kumar, Sumita Das, Dipti Gupta, Ruchi Anand
Summary: This study proposes a strategy that combines organic electronics with biosensor scaffolds to create a compact device for monitoring environmental aromatic pollution. By coupling biosensing protein MopR with an organic electrochemical transistor (OECT), a sensor module capable of efficient detection of phenol was designed. Exclusive phenol detection with minimal loss of sensitivity could be achieved in complex pollutant mixtures and real environmental samples.
Review
Chemistry, Multidisciplinary
Changseok Lee, Hyung-Joon Kang, Sungwoo Hong
Summary: The formation of C-N bonds through hydroamination reactions catalyzed by nickel hydrides has been a topic of recent interest. This approach offers a way to efficiently transform a variety of alkene and alkyne substrates into compounds enriched with C-N bonds. The review provides a concise overview of the underlying reaction mechanisms and aims to stimulate further progress in NiH-catalytic techniques and catalyst design.
Article
Chemistry, Multidisciplinary
Yueci Wu, Lu-Lu Sun, Hai-Hao Han, Xiao-Peng He, Weiguo Cao, Tony D. James
Summary: Drug-induced liver injury (DILI) is a common cause of acute liver failure in the USA and Europe, but most cases can be recovered or prevented by discontinuing the offending drug. Recent research has found that peroxynitrite (ONOO-) can be used as a potential indicator for early diagnosis of DILI, and there is an urgent need to establish a method to detect and track peroxynitrite in DILI cases. In this study, a FRET-based nano fluorescent probe CD-N-I was developed, which showed high selectivity and sensitivity in detecting peroxynitrite. The probe successfully detected exogenous peroxynitrite in live cells and endogenous peroxynitrite in APAP-induced liver injury of HepG2 cells.
Article
Chemistry, Multidisciplinary
Dmitry L. Lipilin, Mikhail O. Zubkov, Mikhail D. Kosobokov, Alexander D. Dilman
Summary: This article describes a direct photocatalytic method for the thiolation of unprotected acids, which was previously challenging. By using a thionocarbonate reagent with an N-O bond, the efficient conversion of carboxylic acids to thiols is achieved.
Article
Chemistry, Multidisciplinary
Jason Malenfant, Lucille Kuster, Yohann Gagne, Kouassi Signo, Maxime Denis, Sylvain Canesi, Mathieu Frenette
Summary: Raman microscopy can reveal compound-specific vibrational fingerprints without sample preparation. The combination of efficient theoretical calculations and a user-friendly software can accurately predict peak positions and provide match scores to assist with structure determination.
Article
Chemistry, Multidisciplinary
Jayoh A. Hernandez, Paul S. Micus, Sean Alec Lois Sunga, Luca Mazzei, Stefano Ciurli, Gabriele Meloni
Summary: Essential trace metals play crucial roles in the survival and virulence of bacterial pathogens. Helicobacter pylori requires nickel for colonization and persistence in the stomach, and NixA is an essential nickel transporter in this process. This study characterizes the selectivity and electrogenic nature of NixA-mediated nickel transport.
Article
Chemistry, Multidisciplinary
Tarali Devi, Kuheli Dutta, Jennifer Deutscher, Stefan Mebs, Uwe Kuhlmann, Michael Haumann, Beatrice Cula, Holger Dau, Peter Hildebrandt, Kallol Ray
Summary: This study emphasizes the importance of subtle electronic changes and secondary interactions in the stability of biologically relevant metal-dioxygen intermediates. It also shows that the role of the chloride ligand in stabilizing the Fe-III-(OOBu)-Bu-t moiety can extend to other anions, including the thiolate ligand.
Article
Chemistry, Multidisciplinary
Jacqueline R. Santhouse, Jeremy M. G. Leung, Lillian T. Chong, W. Seth Horne
Summary: By studying the folding kinetics and mechanism of the BdpA sequence, researchers found that altering the backbone connectivity can affect protein folding. This suggests that protein mimetic chains have a significant degree of plasticity in transitioning between unfolded and folded states.
Article
Chemistry, Multidisciplinary
Divanshu Gupta, Ralf Einholz, Holger F. Bettinger
Summary: This study presents the first direct spectroscopic evidence of a cyclic seven-membered iminoborane. Compared to linear amino-iminoboranes, this cyclic iminoborane exhibits weakened bond strength and lower Lewis acidity value. The study suggests that the reduced ring strain of cyclic iminoborane prevents nitrogen fixation but allows facile (2 + 2) cycloaddition reaction with C2H4.
Article
Chemistry, Multidisciplinary
Renny Mathew, Aniruddha Mazumder, Praveen Kumar, Julie Matula, Sharmarke Mohamed, Petr Brazda, Mahesh Hariharan, Brijith Thomas
Summary: This study reveals the packing arrangement of partially disordered nitro-perylenediimide (NO2-PDI) using a synergistic approach that combines 3D ED, ssNMR, and DFT techniques. By overcoming these challenges, this methodology opens up new avenues for material characterization, driving exciting advancements in the field.