Article
Chemistry, Organic
Victorino Vallejos Gonzalez, Justin Kahle, Christopher Huessler, Robin Heckershoff, A. Stephen K. Hashmi, Bernhard Birenheide, Adrian Hauser, Joachim Podlech
Summary: This paper describes the synthesis of three penta- and three hexahelicenes containing two terminal thiophene units. The syntheses of pentahelicenes involved the 1,4-bisalkynylation of a benzene precursor and double Suzuki coupling in the 2,3-position to introduce thiophene units. The ortho,ortho' fusion yielding the final products was achieved with catalysts such as platinum(II) chloride or JohnPhos-complexed gold(I). A similar approach was used for the synthesis of hexahelicenes, starting with a naphthalene derivative and involving 2,7-bisalkynylation and subsequent double Suzuki coupling. The ortho,ortho' fusion to the respective hexahelicenes was achieved using platinum(II) chloride or, preferably, indium(III) chloride. UV/Vis spectra and cyclic voltammograms were recorded, and HOMO/LUMO gaps were calculated using DFT methods for all helicenes.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Soumik De, Aritra Kumar Dan, Raghaba Sahu, Sagarika Parida, Debadutta Das
Summary: Gold catalysis is a popular and highly innovative field in catalysis research, providing new approaches for chemical transformations from simple starting materials. The application of gold catalysis in the total synthesis of natural products has successfully addressed complex challenges and achieved significant progress.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Review
Chemistry, Organic
Suven Das
Summary: This review highlights novel stereoselective strategies for the synthesis of various heterocycles using isoquinolinium salts. These reactions offer advantages such as high stereoselectivity, readily available starting materials, and mild reaction conditions, and have been successfully used in the synthesis of natural products and bioactive compounds.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Julian Baars, Isabelle Grimm, Dirk Blunk, Joerg-Martin Neudoerfl, Hans-Guenther Schmalz
Summary: A 12-step total synthesis of the natural product dysiherbol A was achieved, revealing the need for revision of the originally proposed structure and absolute configuration. The synthesis involved key steps including Cu-catalyzed addition/enolate-trapping, Au-catalyzed double cyclization, and late installation of the C5-bridgehead methyl group. Spectroscopic measurements confirmed the identity of the synthetic compound with the natural product but with an opposite molecular rotation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Peng Lin, Shugang Xiong, Yutao Rao, Ling Xu, Mingbo Zhou, Bangshao Yin, Atsuhiro Osuka, Jianxin Song
Summary: Intramolecular fusion reactions of a p-terphenylene-bridged Ni-II porphyrin dimer led to the formation of different products depending on the reaction conditions. Oxidation with Fe(OTf)(3) resulted in the syn- and anti-doubly heptagon-fused Ni-II porphyrin dimers, which exhibited enlarged pi-electronic networks likely through a radical mechanism. Treatment with methanesulfonic acid, on the other hand, produced a spiro-pentagon-bridged Ni-II chlorin dimer via acid-catalyzed Friedel-Crafts type cyclization. Additionally, a doubly octagon-fused Ni-II porphyrin dimer was synthesized through a sequence of double meso-formylation, reduction to corresponding diol, and BF3-catalyzed cyclization.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Applied
Ali Wang, Xiaoping Hu, Xin Xie, Yuanhong Liu
Summary: A gold-catalyzed cyclization/cascade skeletal rearrangement of o-cyanophenylalkynones with 3-amino-benzo[d]-isoxazoles has been developed, providing an approach for synthesizing medium-sized benzolactones. Nucleophilic attack preferentially occurs at the keto moiety instead of the gold-carbene, initiating an attractive cascade process involving carbene transfer, 1,2-aryl migration, cycloaddition, and ring-expansion resulting in multiple bonds cleavage of the initial substrates.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Luca C. C. Greiner, Norihito Arichi, Shinsuke Inuki, Hiroaki Ohno
Summary: In this study, phenyl azides substituted by an (alkylphenyl)ethynyl group were found to facilitate benzylic sp(3)(C-H) functionalization under the presence of a JohnPhosAu catalyst, resulting in the synthesis of indole-fused tetra- and pentacycles through divergent N- or C-cyclization. The chemoselectivity of the reaction was found to be influenced by the counter-anion, the electron density of the alpha-imino gold(I) carbene, and the alkyl groups stabilizing the benzylic carbocation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Vipin Singh, Shanta Raj Lakshmi, L. Raju Chowhan
Summary: In this study, a short and efficient method for synthesizing novel polyheterocyclic chromeno spiro-pyrrolidine oxindoles via 1,3-dipolar cycloaddition reaction mediated by graphene oxide (GO) catalyst was reported. The method showed high yields and green synthetic approach, with the catalyst having a low loading and no formation of side products. The products were easily isolated without the use of any chromatographic techniques.
FRONTIERS IN CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Wenqiang Zhou, Song Xi, Haohua Chen, Dan Jiang, Jiao Yang, Shuangwei Liu, Ling He, Hanyue Qiu, Yu Lan, Min Zhang
Summary: Bridged frameworks are important in chemistry and biology, found commonly in pharmaceuticals and natural products. Traditional methods of building these rigid segments at the middle or late stage of synthesis decrease efficiency and specificity. In this study, a novel strategy was used to construct a morphan core equipped with an allene/ketone group through an enantioselective a-allenylation of ketones. The resulting bridged backbone guided the assembly of up to five fusing rings, and the allene and ketone groups allowed precise installation of various functionalities, leading to a concise total synthesis of nine strychnan alkaloids.
Article
Chemistry, Multidisciplinary
Xianghui Liu, Kai Wang, Yan Liu, Can Li
Summary: This work presents a water triggered chemo-divergent enantioselective spiro-annulation and cascade reaction catalyzed by a chiral organic base. By adjusting the ratio of water in the solvent, two new highly efficient asymmetric reactions were developed for the divergent synthesis of spiro- and fused-indanone scaffolds with excellent enantioselectivities. Mechanistic investigations suggest the importance of interfacial hydrogen bonding in achieving switchable reaction pathways.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Jia Wang, Xiao-Xiao Lu, Run-Ping Yang, Zhi-Hao Xiang, Bing-Bing Zhang, Shujun Chao, Lixia Liu, Yunhui Yan, Xuefang Shang
Summary: The practical strategy for the synthesis of spiro[5.5]trienones-fused selenocyanates and spiro[4.5]trienones-fused selenocyanates through electrophilic selenocyanogen cyclization and dearomative spirocyclization is reported. This approach offers mild conditions, broad substrate scope, and good functional group tolerance, showcasing its utility in the late-stage functionalization of nature product and drug molecules.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Aimin Zhang, Gyungah Pak, Suh Young Yu, Sehui Yang, Jimin Kim
Summary: Concise syntheses of naturally occurring gamma-butenolides (+)-xylogiblactones B and C have been achieved for the first time starting from commercial methyl crotonate in 5-8 steps. The synthetic route involves allenoate gamma-addition to racemic aldehydes through kinetic resolution, establishing the required stereochemical framework and axial chirality, followed by oxacyclization via gold catalysis to complete the (+)-xylogiblactone skeleton. Both key transformations proceed in a regio- and stereospecific manner. The synthesis provides stereochemical clarification for (+)-xylogiblactones B and C.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Rinat R. Gubaidullin, Anna Yu Spivak, Valery N. Maistrenko, Lyudmila Parfenova
Summary: Gold(I) chloride complex with triphenylphosphine and metal triflates catalyze the formation of novel [3,2-b]pyrrole-fused pentacyclic triterpenoids from accessible 2-alkynyl derivatives of betulonic, ursonic and oleanonic acids. The reactions proceed in the presence of 5 mol% of the catalyst and provide pyrrole-containing triterpenoids with the isolated yield of 60-86%.
Article
Chemistry, Multidisciplinary
Rawan Alnufaie, Mohamad Akbar Ali, Ibrahim S. Alkhaibari, Subrata Roy, Victor W. Day, Mohammad A. Alam
Summary: A library of bioactive molecules was synthesized efficiently using environmentally friendly solvent acetic acid, resulting in the creation of novel fused-thiazole derivatives. Experimental results showed that some of these compounds exhibited potent growth inhibition against cancer cell lines.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Zhiguo Zhang, Xiaoqing Song, Guofeng Li, Xiang Li, Dan Zheng, Xuna Zhao, Huanran Miao, Guisheng Zhang, Lantao Liu
Summary: This study reports a novel reaction method for the rapid synthesis of polycyclic spiroindolines, containing multiple stereocenters including a quaternary stereocenter. A novel azaphospholidine-containing spiroindoline compound is synthesized for the first time, potentially of interest in synthetic and medicinal chemistry research.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Organic
Andrew D. W. Earl, Freda F. F. Li, Chao Ma, Daniel P. P. Furkert, Margaret A. A. Brimble
Summary: This research describes a facile and efficient synthesis of the [7,6]-spirocyclic core of 13-desmethyl spirolide C, a marine natural product with remarkable bioactivity against biomarkers of Alzheimer's Disease. The synthesis involves an aza-Claisen rearrangement and a highly exo-selective Diels-Alder cycloaddition. This strategy not only provides a more efficient access to the spirocyclic core for the total synthesis of 13-desmethyl spirolide C, but also allows for convenient preparations of analogues for biological evaluation.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Pharmacology & Pharmacy
Johanes K. Kasim, Jiwon Hong, Anthony J. R. Hickey, Anthony R. J. Phillips, John A. Windsor, Paul W. R. Harris, Margaret A. Brimble, Iman Kavianinia
Summary: Pancreatic ductal adenocarcinoma is a debilitating disease with no effective treatments. Trichoderin A, a natural product, shows promise as an anticancer agent. It selectively kills pancreatic cancer cells under glucose deprivation, which is significant given the nutrient-deprived nature of the disease.
Article
Biochemistry & Molecular Biology
Shama Dissanayake, Junming He, Sung H. Yang, Margaret A. Brimble, Paul W. R. Harris, Alan J. Cameron
Summary: A novel antimicrobial peptide called cathelicidin-PY was successfully synthesized, which exhibited broad-spectrum antibacterial and antifungal activity with low toxicity to human cells. Derivatives of this peptide were also synthesized and showed selective inhibition against Gram-negative bacteria E.coli.
Article
Chemistry, Organic
Eilidh G. Young, Phillip S. Grant, Daniel P. Furkert, Margaret A. Brimble
Summary: Lycibarbarines A-C are spirocyclic alkaloids with a unique tetracyclic framework. The first total syntheses of lycibarbarines A-C were achieved over 10 steps. The spiroketal unit of lycibarbarines A-C exhibits unusually high resistance to acid-mediated isomerization and epimerization.
Article
Chemistry, Medicinal
Alexander J. Craig, Yuri Ermolovich, Alan Cameron, Agnes Rodler, Helen Wang, Jeffrey A. Hawkes, Madlen Hubert, Fredrik Bjoerkling, Natalia Molchanova, Margaret A. Brimble, Lindon W. K. Moodie, Johan Svenson
Summary: Small synthetic mimics of cationic antimicrobial peptides are promising compounds for treating persistent microbial infections. In this study, we investigated the activity of 19 linear cationic tripeptides against pathogenic bacteria and fungi, including clinical isolates. Modified hydrophobic amino acids inspired by bioactive marine secondary metabolites were used to create compounds with improved safety profiles. Several compounds showed high activity, particularly against fungal strains, with low off-target toxicity to erythrocytes and HeLa cells, indicating effective ways to tune the activity and selectivity of short antimicrobial peptides.
ACS MEDICINAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Inorganic & Nuclear
Saawan Kumar, Mie Riisom, Stephen M. F. Jamieson, Iman Kavianinia, Paul W. R. Harris, Nils Metzler-Nolte, Margaret A. Brimble, Christian G. Hartinger
Summary: Researchers conjugated a derivative of plecstatin-1 with peptides to enhance their targeting ability towards cancer cells. Metal-peptide conjugates were successfully synthesized and tested for their anticancer activity. Although the activity was relatively low, this study provides a potential strategy to design other metal complexes utilizing the targeting properties of peptides.
INORGANIC CHEMISTRY
(2023)
Editorial Material
Chemistry, Organic
Margaret A. Brimble, Lutz Ackermann, Yan-Mei Li, Monika Raj
Article
Virology
Alice-Roza Eruera, Alice M. McSweeney, Geena M. McKenzie-Goldsmith, Helen K. Opel-Reading, Simone X. Thomas, Ashley C. Campbell, Louise Stubbing, Andrew Siow, Jonathan G. Hubert, Margaret A. Brimble, Vernon K. Ward, Kurt L. Krause
Summary: Norovirus is a major cause of viral gastroenteritis worldwide. This study provides new insights for drug design against GII.4 genogroup of noroviruses.
Article
Chemistry, Organic
C. H. Andy Wong, Jonathan G. Hubert, Kevin J. Sparrow, Lawrence D. Harris, Peter C. Tyler, Margaret A. Brimble
Summary: This study presents a one-pot method for synthesizing similar fleximers using a bifunctional copper catalyst, which can generate aryl azides in situ and react with terminal alkynes to form triazoles.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Xiao-Bo Ding, Alexander Wung, Daniel P. Furkert, Margaret A. Brimble
Summary: We report a facile synthesis of the spirocyclic core of portimines A and B, two natural products with remarkable anticancer, anti-HIV, and antifouling activities. Our strategy involves a scalable Diels-Alder addition and a diastereoselective lactonization, enabling differentiation of the carbonyl groups. This approach overcame issues encountered in previous studies and provided a useful intermediate for the synthesis of portimines.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Shengping Zhang, Luis De Leon M. Rodriguez, Freda F. F. Li, Margaret A. Brimble
Summary: Selective modification of peptides and proteins at tyrosine residues has gained significant attention in recent years. This review provides a comprehensive summary of the latest advancements in tyrosine-selective cleavage, functionalization, and conjugation, complementing the existing body of work on site-specific modification of peptides and proteins. This research holds great relevance across various disciplines, including chemical, biological, medical, and material sciences.
Review
Biochemistry & Molecular Biology
Louise A. A. Stubbing, Jonathan G. G. Hubert, Joseph Bell-Tyrer, Yann O. O. Hermant, Sung Hyun Yang, Alice M. M. McSweeney, Geena M. M. McKenzie-Goldsmith, Vernon K. K. Ward, Daniel P. P. Furkert, Margaret A. A. Brimble
Summary: Viral infections are a major cause of acute morbidity in humans, and efforts have been made to develop drugs to treat associated diseases. Peptide-based enzyme inhibitors, short sequences of three or four residues, are being developed to enhance their activity and pharmaceutical properties. This review focuses on the design of inhibitors targeting highly conserved viral proteases 3C/3CL(pro), which play a key role in viral replication and have minimal similarity with mammalian proteases. The development of P-1 glutamine isosteres to generate potent inhibitors mimicking the natural substrate sequence is highlighted.
RSC CHEMICAL BIOLOGY
(2023)
Article
Chemistry, Organic
Dennise Palpal-latoc, Margaret A. Brimble, Paul W. R. Harris, Aimee J. Horsfall
Summary: Macrocyclic depsipeptides, a class of bioactive natural products, have gained increasing attention due to their antimicrobial activity. However, the low yields in peptide ester (depsipeptide) bond formation have hindered the access to these structures for further studies. In this study, we systematically investigated the factors influencing on-resin depsipeptide bond formation using simplified sequences derived from antibiotic peptides. Our findings highlight the importance of reaction solvent and the number of amino acids in improving the acylation efficiency. The impact of protecting groups and stereochemistry was also evaluated, while the addition of surfactants and 6-ClHOBt showed little effect, and no significant difference was observed between different resins.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Review
Chemistry, Organic
Marzieh Ahangarpour, Iman Kavianinia, Margaret A. Brimble
Summary: Over the last few decades, synthetic organic chemists have been focusing on the design and discovery of chemical reactions that enable the modification of proteins at specific sites. The selective functionalization of peptides and proteins offers an exciting opportunity for creating valuable multicomponent conjugates with diverse applications. Various strategies, including the thia-Michael click addition reaction, have been developed for the selective modification of cysteine-containing proteins. This review summarizes the different reactions for cysteine-selective peptide and protein modification, with a specific focus on the thia-Michael click addition reaction and its applications.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Faiza Diaba, Gisela Trenchs
Summary: The first violet light-mediated synthesis of gamma- and delta-lactams from N-alkenyl trichloroacetamides is reported in this paper. The reactions are conducted in tetrahydrofuran or 2-methyltetrahydrofuran as the sole solvent without catalysts or additives, under non-anhydrous conditions in an air atmosphere where the solvent serves as the radical initiator.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Feroze Hussain, Sajjad Ahmed, Ashiq Hussain Padder, Qazi Naveed Ahmed
Summary: This study reports a novel and efficient one-pot synthesis method for mixed phosphorotrithioates, which does not require supplementary additives and shows broad applicability.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Hyunjin Oh, Ikyon Kim
Summary: A new 1,2,4-triazole-pyrrolo[1,2-a]pyrazine hybrid system, 6-acylpyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazine, was synthesized using a catalyst-free method. This method involved sequential exposure of pyrrole-2-carbonitrile-derived substrates to DMF-DMA and acyl hydrazide, resulting in the formation of acylated pyrazine and 1,2,4-triazole rings, enabling the installation of various substituents at specific positions on the core skeleton.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Ming Yan, Si-fan Wang, Yong-po Zhang, Jin-zhong Zhao, Zhuo Tang, Guang-xun Li
Summary: Here we developed an efficient photocatalytic approach for the convenient preparation of sulfinamides. The reaction allows for the gram-scale preparation of sulfinamides and the one-pot synthesis of various sulfonyl amides.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Farzaneh Bandehali-Naeini, Zahra Tanbakouchian, Noushin Farajinia-Lehi, Nicolas Mayer, Morteza Shiri, Martin Breugst
Summary: Two tandem catalytic systems were developed for the synthesis of novel 3,4-disubstituted maleimides using the same Ugi adducts. Different maleimide structures can be synthesized using either Pd or Cu catalysis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Tanya Raghava, Anjan Chattopadhyay, Subhadeep Banerjee, Nivedita Sarkar
Summary: Amine substitution of two ortho fluorine atoms of tetrafluoroterephthalonitrile through SNAr chemistry is easily achievable. But further fluorine substitution is only possible under forcing conditions, yielding valuable fluorophores for bioimaging.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Review
Chemistry, Organic
Anju Chadha, Santosh Kumar Padhi, Selvaraj Stella, Sowmyalakshmi Venkataraman, Thangavelu Saravanan
Summary: Alcohol dehydrogenases are enzymes that use cofactors for oxidation or reduction reactions of alcohols or carbonyl compounds. They are utilized in green chemistry and have applications in the production of pharmaceuticals. Recombinant enzymes have solved the challenge of producing purified enzymes in large quantities. Engineered alcohol dehydrogenases have been used in asymmetric synthesis in industry. Various methods have been established for regenerating expensive cofactors to make the enzymatic process more efficient and economically viable.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
