Article
Chemistry, Physical
Renat Kadyrov
Summary: An efficient and simple catalytic system has been developed for the hydrogenation of carboxylic esters using commercially available Ru-salts and imidazolium salts. This combination enables the reduction of esters to alcohols at moderate temperature and pressure, offering a practical method for alcohol synthesis.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Minghui Zhu, Qinglong Zhang, Weiwei Zi
Summary: The study presents a dual-metal catalyzed diastereodivergent coupling method for the synthesis of beta-amino alcohols with multiple stereoisomers, enabling the concise preparation of natural products such as mycestericins F and G.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Ashis Das, Luca Buzzetti, Mikus Purins, Jerome Waser
Summary: In this study, we report an enantioselective palladium-catalyzed reaction, which utilizes a trifluoroacetaldehyde-derived tether to react with propargylic amines, generating chiral oxazolidines. Through diastereoselective hydrogenation using a heterogeneous palladium catalyst, protected benzylic amino alcohols can be obtained with yields of 45-87% and enantiomeric excess (ee) values of 84-94%. A catalytic amount of aryl iodide is required for the hydroalkoxylation of alkynes, highlighting the important role of a putative Pd(II)/ArI oxidative addition complex in promoting the oxypalladation/protodemetalation reaction.
Article
Chemistry, Multidisciplinary
Shu-Xin Zhang, Cong Xu, Niannian Yi, Shan Li, Yan-Mei He, Yu Feng, Qing-Hua Fan
Summary: This study successfully achieved the highly efficient ruthenium-catalyzed enantioselective hydrogenation of 9-phenanthrols by trapping the unstable keto tautomers under mild conditions. The method provides a facile access to chiral 9,10-dihydrophenanthren-9-ols with high yield and enantiomeric excess.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Daniel J. Tindall, Steffen Mader, Alois Kindler, Frank Rominger, A. Stephen K. Hashmi, Thomas Schaub
Summary: Sugar alcohols are important for the food industry and can be produced in large quantities with increased yield and stereoselectivity through a homogeneous system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Andrej Emanuel Cotman
Summary: Noyori-Ikariya-type ruthenium(II)-catalysts have been used for 25 years in asymmetric transfer hydrogenation for the synthesis of chiral secondary alcohols. Recent progress has been made in understanding the asymmetric reduction of complex ketones, controlling up to four stereocenters in a single transformation. Intriguing multi-chiral molecular architectures can be prepared via ATH for drug discovery.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Aibo Li, Xinjian Song, Qiao Ren, Peiwang Bao, Xinyu Long, Fuli Huang, Lvjiang Yuan, Jianrong Steve Zhou, Xurong Qin
Summary: A cobalt-catalyzed deuteration of amidoacrylates using deuterated methanol resulted in the synthesis of highly enantioselective α,β-dideuterio-α-amino esters with almost complete deuteration (99%). This new protocol was successfully employed for the preparation of dideuterio-α-amino acid fragments in certain drugs, and also applied in the concise synthesis of dideuterio L-DOPA.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Gollapalli Narasimha Rao, Govindasamy Sekar
Summary: An efficient and reusable catalyst composed of copper-oxide nanoparticles and (R)-(-)-DTBM SEGPHOS has been developed for the chemo- and enantioselective reduction of alpha-keto amides to alpha-hydroxy amides. The reaction showed excellent enantioselectivity and good yields for various alpha-keto amides containing different electron-donating and electron-withdrawing groups. The copper-oxide nanoparticle catalyst maintained its size, reactivity, and enantioselectivity after being reused for four catalytic cycles.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Francisco Gaspar, Guilherme S. Caleffi, Paulo C. T. Costa-Junior, Paulo R. R. Costa
Summary: The Noyori-Ikariya Ru-II complexes were utilized to promote the reduction of C=C/C=O bonds in isoflavones, leading to selective formation of cis-3-phenylchroman-4-ols with different substituents at the 2' position of the B-ring in high yields and excellent enantioselectivities. New synthetic strategies for obtaining enantioenriched isoflavanones and pterocarpans were also demonstrated in this study, showcasing the versatility of the developed method.
Article
Chemistry, Physical
Jiang Wang, Xin Lin, Pan-Lin Shao, Jingyuan Song, Jialin Wen, Xumu Zhang
Summary: This study presents an Rh/DuanPhos-catalyzed double asymmetric hydrogenation of alpha-iminoketones for accessing chiral vicinal amino alcohols. The methodology offers advantages such as one-pot operation, high efficiency, operational simplicity, limited waste, broad reaction scope, and high yields and stereoselectivities. Furthermore, the mechanism of the transformation was revealed to be a stepwise reaction by isolating and analyzing reaction intermediates.
Article
Chemistry, Physical
Masa Sterle, Matej Hus, Matic Lozinsek, Anamarija Zega, Andrej Emanuel Cotman
Summary: Stereopure CF3-substituted syn-1,2-diols were synthesized through the reductive dynamic kinetic resolution of corresponding alkyl ketones, yielding products with >95% ee and >87:13 syn/anti ratio. This method provides a rapid access to stereopure bioactive molecules. Moreover, DFT calculations were conducted on three types of Noyori-Ikariya ruthenium catalysts to demonstrate their general ability to control stereoselectivity through hydrogen bond acceptor SO2 region and CH/pi interactions.
Article
Chemistry, Organic
Lucas Bacheley, Ricardo Molina Betancourt, Rathies Ravindra, Gerard Guillamot, Phannarath Phansavath, Virginie Ratovelomanana-Vidal
Summary: A straightforward method for synthesizing novel families of enantioenriched cis-monofluorinated carbocyclic alcohols has been developed using ATH/DKR. The reaction exhibited high yields (up to 97%), high diastereoselectivity (up to 99:1 dr), and high enantioselectivity (up to 97% ee). Additionally, trans-difluorinated indans, tetrahydronaphthalenes, tetrahydroquinolines, and chromans were synthesized via deoxofluorination of the corresponding cis-fluoro alcohols.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Kurt Puntener, Raphael Bigler, Kenta Stier, Marek P. Checinski
Summary: This study investigates the asymmetric hydrogenation of beta-ketoesters catalyzed by [RuCl2(MeOH)(2)((R)-MeOBIPHEP)]. It is found that HCl acts as both an activator and has a significant impact on the reaction. The study also explains the effects of common phosphorus substituents on the activity of the catalyst.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Jesus Alberto Avendano Villarreal, Fabio Godoy Delolo, Artur Vicari Granato, Elena Vitalievna Gusevskaya, Eduardo Nicolau dos Santos
Summary: Hydroformylation and olefin metathesis are common synthetic tools in the chemical industry. While they have been used in the production of various industrial chemicals within the same synthetic route, there is limited research on combining these two reactions in a one-pot procedure. This study successfully integrated the two reactions and demonstrated efficient synthesis of 2-arylpropanals, valuable compounds for accessing non-steroidal anti-inflammatory drugs.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Antonio Del Vecchio, Jakub Talcik, Sophie Colombel-Rouen, Jan Lorkowski, Melinda R. Serrato, Thierry Roisnel, Nicolas Vanthuyne, Guy Bertrand, Rodolphe Jazzar, Marc Mauduit
Summary: New Blechert-type ruthenium complexes with cyclic(alkyl)(amino)carbene (CAAC) ligands show remarkable thermal stability in solution and excellent catalytic performances in various metathesis reactions. They exhibit high catalytic activity at low loading and can achieve high enantiomeric excess in asymmetric metathesis reactions.
Article
Chemistry, Multidisciplinary
Jianping Yang, Luca Massaro, Weigao Hu, Bram B. C. Peters, Norman Birke, Chayamon Chantana, Thishana Singh, Pher G. Andersson
Summary: Enantioconvergent catalysis allows for the conversion of different isomers of a starting material to a single highly enantioenriched product. The study presents a novel enantioselective double convergent 1,3-rearrangement/hydrogenation of allylic alcohols using an Ir-N,P catalyst, achieving high enantioselectivity and diastereomeric ratio. DFT calculations and control experiments demonstrate the significance of the 1,3-rearrangement in determining the stereochemistry of the reaction.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Bram B. C. Peters, Norman Birke, Luca Massaro, Pher G. Andersson
Summary: The catalytic asymmetric hydrogenation of olefins is a powerful method for synthesizing chiral compounds. By using an iridium N,P-complex catalyst, various prochiral unsaturated amides can be efficiently reduced with high enantioselectivities. The attractive features of this method include its application in the synthesis of fenpropidin and the potential use of isomeric mixtures as starting materials.
Review
Chemistry, Multidisciplinary
Narges Hosseini Nasab, Fereshteh Azimian, Hendrik G. Kruger, Song Ja Kim
Summary: Coumarins, heterocyclic compounds with a benzo-a-pyrone structure, are widely used in pharmacology, cosmetics, chemical, and medicinal industries. Various methods and reactions have been employed to synthesize coumarin derivatives. This review covers the reactions of 3-acetylcoumarin with different reagents and provides an overview of various reactions of 3-acetylcoumarin, including multicomponent, cycloaddition, α-halogenation, aldol condensation, reduction, and 1,2-addition reactions. The synthesis of different compounds starting from 3-acetylcoumarins and their biological activities are presented. This review serves as a valuable resource for researchers in this field.
ARABIAN JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Organic
Srinivas Ambala, Kimberleigh B. Govender, Kamal K. Rajbongshi, Thavendran Govender, Hendrik G. Kruger, Tricia Naicker, Per I. Arvidsson
Summary: Here, an effective and efficient transition metal-free method for the N-arylation of primary sulfonimidamides was reported. The benzyne intermediates generated from silyl aryl triflates successfully coupled with the primary sulfonimidamides, resulting in good to excellent yields. In addition, by adding 18-crown-6, the scope of this method was extended to tertiary sulfonimidamides with moderate to low yields.
TETRAHEDRON LETTERS
(2023)
Article
Chemistry, Organic
Lei He, Bram B. C. Peters, Xu Quan, Shaohu Zhao, Tianrui Huang, Shuting Ren, Pher G. Andersson, Taigang Zhou
Summary: This article describes a method for synthesizing highly enantioselective alpha-chiral amine compounds using NHC, P-iridium complexes catalyzed asymmetric hydrogenation of imines. The hydrogenation proceeds smoothly, even under hydrogen pressure. Experimental results indicate that the reduction process most likely progresses through a combination of direct hydrogenation and a hydrogen transfer process using either H-2 or iPrOH as the reductant, respectively.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Medicinal
Byron K. Peters, Nakita Reddy, Mbongeni Shungube, Letisha Girdhari, Sooraj Baijnath, Sipho Mdanda, Lloyd Chetty, Thandokuhle Ntombela, Thilona Arumugam, Linda A. Bester, Sanil D. Singh, Anil Chuturgoon, Per I. Arvidsson, Glenn E. M. Maguire, Hendrik G. Kruger, Tricia Naicker, Thavendran Govender
Summary: Fi-lactams are the most commonly prescribed antibiotics due to their potent antimicrobial activities, but their efficacy is threatened by the alarming rates of antimicrobial resistance, particularly in carbapenem-resistant Enterobacterales expressing metallo-fi-lactamases (MBLs). In this study, a cyclic zinc chelator called BP1 was developed, which restored the efficacy of meropenem against MBL-expressing bacteria and showed no toxicity to human cells. The study also demonstrated the therapeutic potential of BP1 in reducing bacterial load in infected mice. These findings propose a promising strategy to combat antimicrobial resistance.
ACS INFECTIOUS DISEASES
(2023)
Article
Chemistry, Physical
Nkululeko E. Damoyi, Holger B. Friedrich, Gert H. Kruger, David J. Willock
Summary: Supported vanadium oxides are widely used catalysts for the selective oxidative dehydrogenation of alkanes to alkenes. The activity of these catalysts is influenced by the different oxygen species involved, with singly coordinated vanadyl V(V)=O being the most reactive. Understanding the relative activity of different oxygen species can help improve catalyst design and enhance productivity and selectivity in the reaction.
MOLECULAR CATALYSIS
(2023)
Article
Infectious Diseases
Nakita Reddy, Letisha Girdhari, Mbongeni Shungube, Arnoldus C. Gouws, Byron K. Peters, Kamal K. Rajbongshi, Sooraj Baijnath, Sipho Mdanda, Thandokuhle Ntombela, Thilona Arumugam, Linda A. Bester, Sanil D. Singh, Anil Chuturgoon, Per I. Arvidsson, Glenn E. M. Maguire, Hendrik G. Kruger, Thavendran Govender, Tricia Naicker
Summary: This study evaluated the use of a novel beta-lactamase inhibitor, BP2, in combination with meropenem to overcome resistance in hard-to-treat infectious diseases caused by virulent bacteria expressing beta-lactamases. The results showed that BP2 enhanced the activity of meropenem, exhibiting bactericidal effects with a MIC of <= 1 mg/L and was safe to use at the tested concentrations. BP2 also demonstrated strong inhibitory activity against NDM-1 and VIM-2, specifically targeting MBLs. In a murine infection model, the combination of BP2 and meropenem showed significant efficacy. These promising pre-clinical results make BP2 a suitable candidate for further research and development as a metallo-beta-lactamase inhibitor (MBLI).
Article
Chemistry, Multidisciplinary
Narges Hosseini Nasab, Hussain Raza, Young Seok Eom, Mubashir Hassan, Andrzej Kloczkowski, Lloyd Christopher Chetty, Hendrik Gert Kruger, Song Ja Kim
Summary: A series of 1,3,4-thiadiazole-thiazolidinone derivatives (7a-j) were synthesized and evaluated as carbonic anhydrase inhibitors. Compound 7i showed higher inhibitory activity (IC50 = 0.402 +/- 0.017 mu M) compared to the standard reference acetazolamide (IC50 = 0.998 +/- 0.046 mu M). Kinetic analysis revealed that compound 7i binds competitively to the target enzyme. Compound 7i also exhibited good conformational state and hydrogen bond interactions in the receptor binding pocket, according to molecular docking studies.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Mbongeni Shungube, Ayanda K. Hlophe, Letisha Girdhari, Victor T. Sabe, Byron B. Peters, Nakita Reddy, Kehinde F. Omolabi, Lloyd Chetty, Thilona Arumugam, Anil Chuturgoon, Hendrik G. Kruger, Per I. Arvidsson, Hua-Li Qin, Tricia Naicker, Thavendran Govender
Summary: Beta-lactamases deactivate beta-lactam antibiotics through hydrolysis mechanism. This study developed 11 potential MBL inhibitors that successfully restored the effectiveness of meropenem against NDM-producing Klebsiella pneumoniae infections.
Article
Microbiology
Kehinde F. Omolabi, Nakita Reddy, Sipho Mdanda, Sphamandla Ntshangase, Sanil D. Singh, Hendrik G. Kruger, Tricia Naicker, Thavendran Govender, Sooraj Bajinath
Summary: The recent surge in beta-lactamase resistance has led to the emergence of superbugs, posing a significant threat to public healthcare. This study evaluated the potential of 1,4,7-triazacyclononane-1,4,7 triacetic acid (NOTA) as a metallo-beta-lactamase (MBL) inhibitor in combination with meropenem against MBL producing bacteria. The results showed that NOTA restored the efficacy of meropenem and significantly decreased the colony-forming units of carbapenem-resistant Klebsiella pneumoniae in a murine infection model.
FEMS MICROBIOLOGY LETTERS
(2023)
