Article
Chemistry, Organic
Tong Pan, Pingfan Li
Summary: A one-pot two-step reaction sequence enables allylic C-H cyclopropanation of a-methylstyrene and its derivatives, converting two aliphatic C-H bonds to C-C bonds with high diastereoselectivity and good yield, offering a convenient method for the synthesis of vinyl cyclopropane structures.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Eva Rivera-Chao, Martin Fananas-Mastral
Summary: An efficient and modular approach has been developed for the synthesis of multifunctional tetrasubstituted 1,3-dienes with high levels of regio- and stereoselectivity. This method is based on a tetracomponent reaction involving a borylated dendralene, an organolithium reagent, and two different electrophiles. Mechanistic studies have revealed the pathway of this transformation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Huiling Zhu, Peng Liu, Hongxin Liu, Ebrahim-Alkhalil M. A. Ahmed, Xingen Hu, Juan Li, Hong-Ping Xiao, Xinhua Li, Jun Jiang
Summary: A carboxyl-assisted reaction method has been developed for the site- and enantio-selective additions of polyfunctional nucleophiles to imines and carbonyls. This method provides efficient access to delta-substituted-beta-keto esters and beta-substituted ketones with good yields and enantioselectivities. Additionally, short synthetic routes to bioactive molecules have been achieved.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Qigui Nie, Xianfu Fang, Changyang Liu, Gong Zhang, Xiaohong Fan, Yangfeng Li, Yizhou Li
Summary: This study reported a new DNA-compatible protocol for the transformation of amines into drug-like moieties, expanding the application of DNA-encoded chemical libraries.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Hu Tian, Hong-Ming Zhang, Liang Yin
Summary: In this article, a copper(I)-catalyzed asymmetric conjugate addition/protonation with selenols and alpha-substituted alpha,beta-unsaturated thioamides is described, which produces a series of chiral selenides with high to excellent enantioselectivity. The reaction shows a broad substrate scope for both selenols and alpha-substituted alpha,beta-unsaturated thioamides. The catalytic system is also successfully used for asymmetric selenation of beta-substituted alpha,beta-unsaturated thioamides. A [Cu-(R,R-P)-TANIAPHOS]-SePh species is identified by Se-77 NMR spectra, with a chemical shift at delta 462 ppm. Furthermore, a {[Cu-(R)-TOL-BINAP]-SePh}(2) species is characterized by X-ray analysis, confirming the formation of Cu-Se bond in the reaction. Finally, the straightforward transformations of the thioamide group to amine and thioester are demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Kanniyappan Silambarasan, Gangarajulu Kesavulu, Arava Amaranadha Reddy, Kavirayani R. Prasad
Summary: Reaction of -halo-substituted nonracemic beta-sulfinamido ketones with NaH affords beta-amino cyclohexyl ketones in excellent yields and diastereoselectivity via intramolecular C-alkylation adjacent to the carbonyl group. This reaction is general and can be used for the synthesis of various cyclohexyl amino ketones and tetrahydropyrans with amine and acyl substitutions.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Damien Bouchet, Thomas Varlet, Geraldine Masson
Summary: Enamide and enecarbamate derivatives with nucleophilic and electrophilic centers have dual reactivity, enabling difunctionalization and increased structural complexity. Strategies such as using chiral phosphoric acids and visible-light-promoted atom transfer radical additions have been employed to overcome stability, competititveness, and compatibility issues. The functionalization of these derivatives is a valid synthetic strategy for obtaining important building blocks.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Organic
Jian Yang, Siliang Ming, Gang Yao, Haifeng Yu, Yu Du, Jun Gong
Summary: An efficient asymmetric [4 + 2] cyclization reaction has been developed using a chiral-at-metal rhodium complex as the catalyst. Enantioenriched chroman derivatives with multiple stereocenters were obtained in high yields and good stereoselectivities. This reaction represents the first catalytic asymmetric [4 + 2] cyclization using chiral Lewis acids as catalysts and provides a useful method for constructing chiral chroman skeletons.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Fu-Yu Li, Bei Wang, Hong Xu, Yao Xiao, Dong-Wei Huang, Ji-Yu Wang
Summary: The convenient synthesis of diverse and complex poly-substituted beta-alkenyl valerolactones is achieved through Fe(iii)-catalyzed reduction radical tandem strategy of 2,3-dienoates and allyl alcohols. The allyl alcohols can undergo simultaneous transformations into alkyl radicals and allyl ester intermediates under Fe(iii) catalysis, which then react via Michael addition to form the desired products. Notably, this method also enables the preparation of spiro-valerolactones and cyclo-valerolactones, as well as the transformation of beta-alkenyl valerolactones into previously unreported pyrazole lactone compounds.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Dan Yang, Xiong Wu, Xiao-Jie Zheng, Jian-Hua Xie, Qi-Lin Zhou
Summary: An efficient asymmetric hydrogenation method using a chiral spiro iridium catalyst has been developed to convert racemic gamma-substituted cyclic beta-ketoesters into chiral cyclic beta-hydroxy esters with three stereocenters. The reaction provides high yields (84-97%) with good to excellent enantioselectivities (69->99% ee) and cis,cis-selectivities (up to >99:1).
Article
Chemistry, Organic
Yuhong Tian, Fengdi Wu, Shiqi Jia, Xiangnan Gong, Hui Mao, Pengfei Wang, Wenling Qin, Hailong Yan
Summary: An organocatalytic asymmetric protocol for constructing tetrasubstituted carbon stereocenters with three heteroatoms is reported. The reaction proceeds via an enantioselective intramolecular cyclization reaction of vinylidene ortho-quinone methide (VQM) with imidates to form pentacyclic heterocycles. The resulting tetrasubstituted carbon center is stable under high temperatures and conditions for further transformations.
Article
Chemistry, Organic
Eun Chae Son, Seung Yeon Kim, Sung-Gon Kim
Summary: Organocatalytic enantioselective intramolecular oxa-Michael reactions can efficiently produce 1,3-dihydroisobenzofuranyl-1-methylene ketones and esters with high yields and enantioselectivities.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Biochemistry & Molecular Biology
Jianlin Han, Jorge Escorihuela, Santos Fustero, Aitor Landa, Vadim A. Soloshonok, Alexander Sorochinsky
Summary: This review critically discusses the literature data on the preparation of substituted GABA derivatives using the Michael addition reaction. Special attention is paid to asymmetric methods featuring synthetically useful stereochemical outcomes and operational simplicity.
Article
Chemistry, Multidisciplinary
Tom D. D'Arcy, Mark R. J. Elsegood, Benjamin R. Buckley
Summary: The highly enantioselective organocatalytic tandem o-HPD-[4+2] reaction described offers a practical method for the synthesis of complex scaffolds. This approach utilizes a chiral oxaziridinium organocatalyst to afford dearomatized products in high enantioselectivity, demonstrating its potential for gram-scale applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Wang Yao, Chuan-Jun Lu, Jia Feng, Ren-Rong Liu
Summary: This study reports a novel method for the enantioselective synthesis of axially chiral 2,2' difluoro-1-biaryls using a palladium and chiral amino acid catalyzed atroposelective C-H olefination. The results demonstrate that a variety of polyfluoro-substituted biaryls can be efficiently synthesized under mild conditions with excellent enantioselectivity.
Article
Multidisciplinary Sciences
Dan Wu, Pol Mac Aonghusa, Donal F. O'Shea
Summary: The study found that countries with comprehensive COVID-19 testing regimes experienced faster declines in infection rates, highlighting the importance of testing in epidemic control. Analysis of healthcare worker infection data can provide valuable insights into disease progression, differentiate infection risks, and guide overall population control measures.
Article
Multidisciplinary Sciences
Jeffrey Dalli, Eamon Loughman, Niall Hardy, Anwesha Sarkar, Mohammad Faraz Khan, Haseeb A. Khokhar, Paul Huxel, Donal F. O'Shea, Ronan A. Cahill
Summary: The combination of ICG and NIR endoscopy allows real-time observation of tissue microperfusion, with the ability to distinguish tumors from normal tissue through video software fluorescence analysis. ICG administration followed by endo-laparoscopic imaging of colorectal tumors provides detailed data analysis for up to 20 minutes.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Multidisciplinary
Sheila Fitzgerald, Donal F. O'Shea
Summary: The importance of bioconjugation reactions in cell specific targeting and dual therapeutic plus diagnostic medical applications continues to grow. This study successfully achieved continuous flow bioconjugations between strained alkyne substituted carbohydrate and therapeutic peptide biomolecules with azide and tetrazine substituted fluorophores. The use of tetrazine cycloadditions proved to be more favorable than azide cycloadditions, and continuous flow fluorogenic bioconjugations enabled real-time monitoring of the reaction.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Review
Chemistry, Medicinal
Oluwakanyinsolami Netufo, Kate Connor, Liam P. Shiels, Kieron J. Sweeney, Dan Wu, Donal F. O'Shea, Annette T. Byrne, Ian S. Miller
Summary: Glioblastoma (GBM) is the most aggressive adult brain tumor with a dismal survival rate. Maximal safe resection is crucial for improving patient survival. Using novel dyes to target specific parts of the tumor microenvironment may reduce residual tumor and improve patient outcomes.
Article
Chemistry, Multidisciplinary
Dan Wu, Gonzalo Duran-Sampedro, Sheila Fitzgerald, Massimiliano Garre, Donal F. O'Shea
Summary: Sequential azide/diyne cycloadditions were used for efficient macrocyclization of a bis-azido aza-dipyrrin. Macrocyclic aza-dipyrrin could be obtained in just 30 minutes at room temperature in water, with measurable changes in fluorescence intensity and lifetimes during the reaction. Live cell microscopy demonstrated the suitability of aza-dipyrrins for confocal and STED super-resolution imaging, and a bioorthogonal response to macrocyclization was observed in cellular compartments. These findings will encourage further exploration of the sensing and imaging applications of aza-dipyrrins.
CHEMICAL COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Niamh Curtin, Massimiliano Garre, Dan Wu, Donal F. F. O'Shea
Summary: BF2-azadipyrromethenes are versatile fluorophores used for cellular and in vivo imaging in the near-infrared and far-red regions. However, their usage with super-resolution imaging techniques like STED nanoscopy has not been explored. In this study, a series of structurally related BF2-azadipyrromethenes were evaluated for their suitability in STED imaging. The study demonstrated successful live cell STED imaging using far-red emitting BF2-azadipyrromethenes, achieving resolution below the diffraction limit.
Letter
Toxicology
Neal L. Benowitz, Christopher Havel, Peyton Jacob, Donal F. O'Shea, Dan Wu, Jefferson Fowles
JOURNAL OF MEDICAL TOXICOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Cathal Caulfield, Dan Wu, Ian S. Miller, Annette T. Byrne, Pol Mac Aonghusa, Sergiy Zhuk, Lorenzo Cinelli, Elisa Bannone, Jacques Marescaux, Sylvain Gioux, Michele Diana, Taryn L. March, Alexander L. Vahrmeijer, Ronan Cahill, Donal F. O'Shea
Summary: A series of near-infrared fluorophores with mono- and bis-polyethylene glycol (PEG) substitution were synthesized for fluorescence guided intraoperative imaging, primarily for ureter identification. The bis-PEGylation improved the aqueous fluorescence quantum yields, with optimal PEG chain lengths of 2.9 to 4.6 kDa. Successful fluorescence identification of ureters was achieved in rodent and porcine models, with 3-D emission heat map imaging revealing spatial and temporal changes in intensity. These fluorophores can be spectrally distinguished from the clinically-used dye indocyanine green, suggesting their potential for intraoperative color coding of different tissues.
Article
Chemistry, Multidisciplinary
Cathal Caulfield, Dan Wu, Massimiliano Garre, Donal F. O'Shea
Summary: Three bis(anilino)-substituted NIR-AZA fluorophores were designed, synthesized, and tested for live-cell microscopy imaging in the 800-850 nm spectral range. The synthetic route allowed for the introduction of tailored peripheral substituents to guide sub-cellular localization and imaging. Successful imaging of lipid droplets, plasma membrane, and cytosolic vacuoles was achieved, and the photophysical and ICT properties of each fluorophore were examined.
Review
Chemistry, Multidisciplinary
Niamh Curtin, Massimiliano Garre, Jean-Baptiste Bodin, Nicolas Solem, Rachel Meallet-Renault, Donal F. O'Shea
Summary: A bio-responsive nanoparticle was formed by directing self-assembly of a hydrophobic NIR-fluorophore with poloxamer P-188, enabling the observation of lipid droplet biogenesis in real-time within cells.
Proceedings Paper
Engineering, Biomedical
Ra'ed Malallah, Gareth Gallagher, Niall Hardy, Jeffrey Dalli, Dan Wu, Donal F. O'Shea, John Sheridan, Ronan Cahill
Summary: This study developed a flexible NIR endoscope prototype for real-time classification of intestinal diseases by transmitting excitation light and collecting ICG fluorescence via fibers. The results showed that optimizing ICG concentration and using filters can improve signal strength, but further design improvements are needed for better performance.
CLINICAL BIOPHOTONICS II
(2022)
Article
Medicine, General & Internal
Niamh Curtin, Dan Wu, Ronan Cahill, Anwesha Sarkar, Pol Mac Aonghusa, Sergiy Zhuk, Manuel Barberio, Mahdi Al-Taher, Jacques Marescaux, Michele Diana, Donal F. O'Shea
Summary: Dual emissions at around 700 and 800 nm have been achieved from a single fluorophore, allowing for successful lymph node mapping in a large animal model. The synthesized fluorophore with hydrophilic and phobic features was non-toxic and compatible with clinical systems.
INTERNATIONAL JOURNAL OF MEDICAL SCIENCES
(2021)
Article
Crystallography
Marco Blangetti, Donal F. O'Shea
X-RAY STRUCTURE ANALYSIS ONLINE
(2020)
Article
Chemistry, Organic
Marco Blangetti, Donal F. O'Shea
TETRAHEDRON LETTERS
(2020)
Article
Crystallography
Donal F. O'shea, Roger D. Sommer, Masahiko Taniguchi, Jonathan S. Lindsey
X-RAY STRUCTURE ANALYSIS ONLINE
(2020)
