Article
Chemistry, Multidisciplinary
Andres Arribas, Martin Calvelo, David F. Fernandez, Catarina A. B. Rodrigues, Jose L. Mascarenas, Fernando Lopez
Summary: The study presents a versatile and highly enantioselective intramolecular hydrocarbonation reaction for the synthesis of heteropolycyclic systems with chiral quaternary carbon stereocenters. The method relies on an iridium-(I)/bisphosphine chiral catalyst, yielding fused indole and pyrrole products with high enantiomeric excesses. DFT computational studies provided a detailed mechanistic profile and identified weak non-covalent interactions as key factors controlling the enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Xiang-Ting Min, Ding-Wei Ji, Yu-Qing Guan, Shi-Yu Guo, Yan-Cheng Hu, Boshun Wan, Qing-An Chen
Summary: Transition metal catalyzed decarbonylation offers a unique synthetic strategy for new chemical bond formation. The study developed a visible light induced rhodium catalysis for decarbonylative coupling of imides with alkynes under ambient conditions, revealing the rhodium complex serves as both the catalytic center and photosensitizer. This visible light promoted catalytic decarbonylation strategy opens up new opportunities for re-evaluating old transformations with ligand dissociation as a rate-determining step.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Jan Ulc, Jaroslav Jacko, Ivana Cisarova, Lubomir Pospisil, David Necas, Martin Kotora
Summary: Here, the design and synthesis of a series of novel cationic nitrogen-embedded polyaromatic hydrocarbons with a planar geometry are reported. The synthesis pathway is based on catalytic C-C/C-H bond activation relay, enabling the preparation of selectively-regioselective 5,6,10,11-tetrasubstituted naphtho[2,1,8-ija]quinolizinium salts with various substituents. Single-crystal X-ray analysis confirmed the planarity of the quinolizinium core. Most of the synthesized compounds exhibited strong fluorescence, ranging from 420-600 nm, depending on the substitution pattern. DFT calculations revealed that the LUMO is always distributed over the quinolizinium framework while the delocalization of HOMO is related to the substitution pattern. Electrochemical measurements showed irreversible reduction of all compounds, which is consistent with the calculated location of LUMO orbitals.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Johannes Grosskopf, Alexandra A. Heidecker, Thorsten Bach
Summary: Racemic 3-substituted oxindoles can be converted into enantiomerically pure or enriched material through photochemical deracemization process. Light energy compensates for the loss of entropy and enables predictable editing of the stereogenic center. The obtained oxindoles are valuable intermediates for further transformations with complete retention at the stereogenic center.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yuri Saito, Jun Kikuchi, Chen Wang, Naohiko Yoshikai
Summary: We report the design and development of Co/Al and Co/Mg bimetallic catalysts supported by a phosphine/secondary phosphine oxide (PSPO) bifunctional ligand for the selective C-H alkenylation of nitrogen-containing heteroarenes with alkynes. These catalysts enable the alkenylation of pyridine, pyridone, and imidazo[1,2-a]pyridine derivatives at the C-H site proximal to the Lewis basic nitrogen or oxygen atom, with a selectivity profile distinct from previously developed cobalt-diphosphine/aluminum catalyst. The alkenylated products were obtained in moderate to good yields using various heterocycles and differently substituted internal alkynes. Kinetic isotope effect experiments suggest the irreversibility of the C-H activation step, the relevance of which to the rate-limiting step depends on the reaction conditions. Density functional theory calculations indicate that ligand-to-ligand hydrogen transfer is the common mechanism of C-H activation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Mo Chen, John Montgomery
Summary: Regio- and enantioselective functionalization of heteroarene C-H bonds in the absence of directing groups has been a long-standing challenge. In this study, we developed a new approach for intermolecular enantioselective C-H alkylation of heteroarenes using nickel catalysts. The reaction can be carried out under mild conditions without the need for Lewis acid co-catalysts. Synthesis of NHC nickel complexes stabilized with 1,5-hexadiene improved the functional group tolerance and heteroarene scope. Mechanistic investigations revealed a ligand-to-ligand hydrogen transfer pathway.
Article
Chemistry, Physical
Raju S. Thombal, Peter Yuosef M. Rubio, Daesung Lee, Debabrata Maiti, Yong Rok Lee
Summary: Metal catalyzed cascade C-H activation/annulation is a highly promising approach for the construction of aromatic and heteroaromatic compounds. Pd-complexes play a crucial role in this method, enabling high catalytic efficiency through the activation of molecules bearing a directing group.
Article
Chemistry, Multidisciplinary
Ji-Hang Xu, Zi-Kui Liu, Yan-Liu Tang, Yang Gao, Xiao-Qiang Hu
Summary: An unprecedented ring-opening cross-coupling of 1,2-oxazetidines with arylboronic acids using copper catalysis has been achieved. This reaction offers simple operation, inexpensive catalyst, broad scope, and high regioselectivity, leading to a wide range of aminomethylation products. Furthermore, the obtained products can be further transformed and bioactive acids can be modified.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Nihad Salameh, Federica Valentini, Olivier Baudoin, Luigi Vaccaro
Summary: We report a general and efficient enantioselective C-H arylation of aryl bromides using BozPhos as the bisphosphine ligand and SP-NHC-PdII as recoverable heterogeneous catalyst. By exploiting the release and catch mechanism of action, high enantioselectivities were achieved across different substrates containing methyl, cyclopropyl and aryl C-H bonds. The developed catalytic system provides a more sustainable solution for the synthesis of high added-value chiral products through recycling of the precious metal.
Article
Chemistry, Multidisciplinary
Shengjun Ni, Matic Hribersek, Swarna K. Baddigam, Fredric J. L. Ingner, Andreas Orthaber, Paul J. Gates, Lukasz T. Pilarski
Summary: This new mechanochemical method enables highly regioselective C-H methylation of (hetero)arenes, showing excellent functional-group compatibility and shorter reaction times, and can be used for the synthesis of biologically active compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Yasunori Minami, Hitomi Miyamoto, Yumiko Nakajima
Summary: Furfural and its derivatives were subjected to alkenylation with alkynes via alpha-C-H activation in the presence of a palladium/carboxylic acid catalyst, leading to the formation of corresponding single and double alkenylated products while maintaining the reactivity of the aldehyde group. This catalytic system enabled selective alkenylation of furan substrates with electron-withdrawing substituents.
Review
Chemistry, Multidisciplinary
Yang Zhang, Michal Szostak
Summary: Total synthesis is the perfect combination of art and science, and C-H functionalization provides a powerful platform for rapid synthesis of complex natural products and changes the design of retrosynthetic strategies, leading to natural product scaffolds with enhanced biological activities.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Applied
Kenji Matsumoto, Rina Nakano, Ken-ichi Yamada, Tsukasa Hirokane, Masahiro Yoshida
Summary: This study reports an efficient platform for the one-step construction of nitrogen-containing polycyclic frameworks using a heterogeneous platinum-catalyzed oxidative alpha,beta-C(sp(3))-H dual functionalization of saturated cyclic amines. By conducting a tandem oxidative dehydrogenation/hetero Diels-Alder reaction under mild aerobic conditions, tetracyclic octahydro-dipyrroloquinoline frameworks were synthesized in good yields. The reaction was successfully applied to the one-step synthesis of natural products incargranine B aglycone and seneciobipyrrolidine. This study provides an efficient and rapid approach to nitrogen-containing fused tetracyclic compounds in a highly atom-economical manner.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Balazs L. Toth, Gergo Salyi, Attila Domjan, Orsolya Egyed, Attila Benyei, Zsombor Gonda, Zoltan Novak
Summary: The study reports a stereoselective procedure for direct fluorovinylation of aromatic and heteroaromatic scaffolds utilizing palladium-catalyzed ortho C-H activation reaction of aniline derivatives. The use of non-symmetrical aryl(fluoroalkenyl)-iodonium salts as fluoroalkenylating agents allows mild reaction conditions, and feasibility has been demonstrated through over 50 examples.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Takeru Miyakoshi, Nadja E. Niggli, Olivier Baudoin
Summary: In the past years, Pd-0-catalyzed C(sp(3))-H activation has provided efficient and economical methods for synthesizing carbo- and heterocycles via direct C(sp(2))-C(sp(3)) bond formation. This study reports a 1,4-Pd shift that enables the synthesis of N-heterocycles, which are difficult to build through direct reactions. The reaction involves the 1,4-Pd shift of o-bromo-N-methylanilines at the N-methyl group, followed by intramolecular trapping and remote C-C bond formation, resulting in the formation of biologically relevant isoindolines and beta-lactams. The selectivity of the reaction is influenced by the choice of ligand, with NHCs favoring the formation of products through remote C-C coupling.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Energy & Fuels
Sandro L. Barbosa, Milton S. de Freitas, Wallans T. P. dos Santos, David Lee Nelson, Maria Betania de Freitas Marques, Stanlei Klein, Giuliano C. Clososki, Franco J. Caires, Eduardo J. Nassar, Lucas D. Zanatta, Foster A. Agblevor, Carlos A. M. Afonso, Adriano C. Moraes Baroni
Summary: Activated charcoal prepared by ZnCl2 activation can be used for the adsorptive purification of pretreated glycerol. The surface properties of the activated charcoal are suitable for increasing glycerol concentration effectively through gravity filtration at room temperature. The activated charcoal can be regenerated through washing and heating treatment for reuse.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Materials Science, Biomaterials
Marcela Tavares Luiz, Juliana Santos Rosa Viegas, Juliana Palma Abriata, Larissa Bueno Tofani, Miguel de Menezes Vaidergorn, Flavio da Silva Emery, Marlus Chorilli, Juliana Maldonado Marchetti
Summary: This study focused on developing folate-modified TPGS transfersomes containing docetaxel (TF-DTX-FA) for improving GBM treatment. TF-DTX-FA demonstrated high cytotoxicity and permeability, as well as a stronger selectivity for tumor cells compared to control groups. This suggests the potential of TF-DTX-FA as a targeted treatment for GBM.
MATERIALS SCIENCE AND ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Rafaely N. Lima, Artur de L. L. Vaz, Giuliano C. Clososki, Andre L. M. Porto
Summary: Biocatalytic methods and continuous-flow systems are effective approaches for obtaining organic compounds, increasing synthesis efficiency and reducing reaction time, which contribute to sustainable synthesis of compounds with cosmetic potential and pharmacological properties.
Article
Cell Biology
Fabiana Albani Zambuzi, Priscilla Mariane Cardoso-Silva, Ricardo Cardoso Castro, Caroline Fontanari, Flavio da Silva Emery, Fabiani Gai Frantz
Summary: Decitabine treatment enhances bacterial phagocytosis and IL-8 release in monocytes, but impairs their microbicidal activity. It also promotes M2-like profile during monocyte-to-macrophage differentiation. In addition, decitabine reduces inflammatory cytokine release during macrophage-lymphocyte co-culture, indicating a potential therapeutic role in immune response modulation.
Article
Chemistry, Applied
Camila R. S. Bertallo, Leonardo S. Berlim, Danilo S. Olivier, Thais R. Arroio, Amando S. Ito, Giuliano C. Clososki
Summary: In this study, 20 novel fluorescent 5-carbonylated 2-arylindolizines derivatives were synthesized through the reaction between organolithium intermediates with different electrophiles. The photophysical properties, including electronic absorption spectra, fluorescence emission, quantum yield, and Stokes shift, were evaluated to investigate the effects of substituents. The results showed variations in absorbance peaks, fluorescence emission, decay times, quantum yield values, and Stokes shifts, with DFT calculations also performed for further analysis.
Article
Biochemical Research Methods
Rodrigo Brito de Mello, Flavio da Silva Emery
Summary: Functionalization of BODIPY dyes through ring fusion on opposite faces of dipyrromethene cores can modulate photophysical properties and increase brightness. Recently synthesized N-bridged arylated BODIPYs exhibit intense brightness and blue-shifted emission, showing potential for applications as probes.
JOURNAL OF FLUORESCENCE
(2022)
Article
Biochemistry & Molecular Biology
Sandro L. Barbosa, Adeline C. Pereira Rocha, David Lee Nelson, Milton S. de Freitas, Antonio A. P. Fulgencio Mestre, Stanlei I. Klein, Giuliano C. Clososki, Franco J. Caires, Danilo L. Flumignan, Leticia Karen dos Santos, Alexandre P. Wentz, Vanya M. Duarte Pasa, Regiane D. Fernandes Rios
Summary: SiO2-SO3H catalyst was used to catalyze the transesterification of triglycerides in waste cooking oil with methanol, and the addition of co-catalysts improved the concentration of FAMEs. Furthermore, all three catalysts showed successful conversion of triglycerides to FAME esters in the more polar solvent DMSO. A simplified mechanism was proposed to explain the experimental results.
Article
Chemistry, Multidisciplinary
Tomas Horsten, Temitayo Omowumi Alegbejo Price, Luc Van Meervelt, Flavio da Silva Emery, Wim Dehaen
Summary: The Lewis acid mediated Nenitzescu reaction unexpectedly produces rearranged 2-imidazolidinone 5-hydroxybenzofurans. Optimization and scope study were conducted. A one-pot two-step synthesis was achieved starting from 1,2-diaminoethane, diethyl acetylene dicarboxylate, and 1,4-benzoquinone. A plausible reaction mechanism was proposed.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
A. M. Firsov, M. S. F. Franco, D. Chistyakov, S. Goriainov, M. G. Sergeeva, E. A. Kotova, M. A. Fomich, A. Bekish, O. L. Sharko, V. V. Shmanai, R. Itri, M. S. Baptista, Y. N. Antonenko, M. S. Shchepinov
Summary: Lipid peroxidation plays a crucial role in age-related neurological disorders and other conditions. Light irradiation can trigger lipid peroxidation, but introducing deuterated polyunsaturated fatty acids into membrane lipids can provide protection. Experimental results confirm the effectiveness of this method in protecting against lipid peroxidation and enhancing the protective effects of tocopherol.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
(2022)
Article
Chemistry, Organic
Elenilson F. da Silva, Krist Helen Antunes Fernandes, Denise Diedrich, Jessica Gotardi, Marcia Silvana Freire Franco, Carlos Henrique Tomich de Paula da Silva, Ana Paula Duarte de Souza, Simone Cristina Baggio Gnoatto
Summary: Respiratory syncytial virus (RSV) is a common cause of acute respiratory infections in infants, and the current treatment drug ribavirin has limitations due to its side effects. This study designed two new anti-RSV drugs and found that compound 8 may be a potential candidate.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Medicinal
Andre Berndt Penteado, Haifa Hassanie, Renan Augusto Gomes, Flavio da Silva Emery, Gustavo Henrique Goulart Trossini
Summary: This article describes the inhibitory mechanisms and binding modes of human sirtuin 2 (hSIRT2) inhibitors, providing insights for the design of new hSIRT2 inhibitors and development of therapeutic agents targeting this epigenetic enzyme.
FUTURE MEDICINAL CHEMISTRY
(2023)
Article
Chemistry, Medicinal
Glaucio Monteiro Ferreira, Thales Kronenberger, Vinicius Goncalves Maltarollo, Antti Poso, Fernando de Moura Gatti, Vitor Medeiros Almeida, Sandro Roberto Marana, Carla Duque Lopes, Daiane Yukie Tezuka, Sergio de Albuquerque, Flavio da Silva Emery, Gustavo Henrique Goulart Trossini
Summary: The etiological agent of Chagas disease, Trypanosoma cruzi, relies on precise epigenetic regulation during host transitions. In this study, we used molecular modelling and experimental validation to discover new inhibitors from commercially available compound libraries. Six inhibitors were selected from virtual screening and validated on the recombinant Sir2 enzyme. The most potent inhibitor (CDMS-01, IC50 = 40 mu M) was chosen as a potential lead compound.
Article
Chemistry, Medicinal
Maria Dichiara, Quillon J. Simpson, Antonio Quotadamo, Hitesh B. Jalani, Anson X. Huang, Caroline C. Millard, Dana M. Klug, Edwin G. Tse, Matthew H. Todd, Daniel Gedder Silva, Flavio da Silva Emery, J. Eric Carlson, Shao-Liang Zheng, Margot Vleminckx, An Matheeussen, Guy Caljon, Michael P. Pollastri, Peter Sjo, Benjamin Perry, Lori Ferrins
Summary: Leishmaniasis is a group of diseases caused by Leishmania parasites, with visceral, cutaneous, or mucocutaneous manifestations. It is a neglected tropical disease, despite its significant mortality and morbidity. Current treatments have limitations, such as variable efficacy, toxicity, resistance, and limited bioavailability, highlighting the need for novel and affordable therapeutics.
ACS INFECTIOUS DISEASES
(2023)
Article
Chemistry, Multidisciplinary
Elizabeth V. Bedwell, Flavio da Silva Emery, Giuliano C. Clososki, Patrick G. Steel
Summary: Heterocycles are important in fragment-based drug discovery due to their prevalence in biologically active compounds. This study describes the synthesis of 5-halo-1H-pyrazolo[3,4-c]pyridine scaffolds and demonstrates how these compounds can be selectively elaborated along multiple growth-vectors. The findings highlight the potential utility of pyrazolo[3,4-c]pyridines in fragment-based drug discovery.
Article
Chemistry, Organic
Paulo Eliandro da Silva Junior, Shaiani Maria Gil de Melo, Murilo Helder de Paula, Ricardo Vessecchi, Till Opatz, James E. H. Day, A. Ganesan, Flavio da Silva Emery
Summary: This article discusses the reactivity of 6-azaindazole and 2,6-naphthyridine, which are important in fragment-based drug discovery. The article introduces selective functionalization methods for pyridone and pyrazole, as well as a new method for selective functionalization of heterocycle 1.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
