Article
Chemistry, Multidisciplinary
Dmitry S. Belov, Gabriela Tejeda, Charlene Tsay, Konstantin V. Bukhryakov
Summary: Vanadium-based catalysts have been demonstrated to catalyze ring-closing olefin metathesis reactions by well-defined V chloride alkylidene phosphine complexes, exhibiting good functional group tolerance. The properties of the imido group and phosphine were found to play a crucial role in the stability of active intermediates.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Valerio Sabatino, Dario Staub, Thomas R. Ward
Summary: The synthesis of N-substituted indoles via ring-closing metathesis of indole precursors with N-terminal alkenes was reported. Good yields (up to 72%) were achieved in aqueous metathesis using commercial catalysts or artificial metalloenzymes. Furthermore, the presence of a second metathesis substrate increased the yield of N-acetylindole.
Article
Chemistry, Organic
Fatema Jagot, Songeziwe Ntsimango, Kennedy J. Ngwira, Manuel A. Fernandes, Charles B. de Koning
Summary: This article describes the key steps in the synthesis of derivatives of angucycline, tetrangulol, including the catalyzed SuzukiMiyaura cross-coupling reaction, iron-catalyzed ring-closing carbonyl-olefin metathesis reaction, and late-stage oxidation reaction. The chlorinated compounds were obtained as final products.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Polymer Science
Mohammad Yasir, Andreas F. M. Kilbinger
Summary: Norbornene and cyclohexene show different polymerization behaviors using Grubbs' catalysts due to their varying ring strain energy levels; a sequence-selective cascade polymerization of a monomer containing both rings resulted in polymers with moderate molecular weight dispersities and good control over molecular weight.
Article
Chemistry, Multidisciplinary
Nils Ansmann, Thaddaus Thorwart, Lutz Greb
Summary: The Lewis superacid bis(perchlorocatecholato)silane catalyzes C-O bond metathesis of alkyl ethers with high efficiency, enabling chemoselective ring contractions of macrocyclic crown ethers and unprecedented ring-closing metathesis of polyethylene glycols for polymer-selective degradation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ammundi Jayavel Chirranjeevi Padmashrija, Sathananthan Kannadasan, Ponnusamy Shanmugam
Summary: A convenient and efficient synthesis of 3-spiro cycloalkene fused 7-aza-2-indalones has been achieved via ring-closing metathesis (RCM) using Grubbs-II catalyst from 3,3'-di- or N,3,3'-tri-allyl/homoallyl/pentenyl 7-aza-2-indalones. The reaction scope was demonstrated by synthesizing spiro products of various ring sizes (n=5, 7, and 18) with different alkenylation agents as substrates. In addition to typical RCM products, a cross metathesis (CM) product and a macrocyclic, 18-membered bis-spirodiene were also observed.
Article
Chemistry, Physical
Ulrich Tallarek, Janika Hochstrasser, Felix Ziegler, Xiaohui Huang, Christian Kubel, Michael R. Buchmeiser
Summary: The study quantified the effects of spatial confinement on hindered transport in mesoporous silica particles using reconstructions of their morphology as geometrical models in diffusion simulations, examining the interactions between tracers and pore space confinement based on the tracer to mean mesopore size ratio. The hindrance factors derived for different ratios quantify the hindrance of diffusion through the materials compared to free diffusion, providing insights into morphology-transport relationships and the immobilization, formation, and transport of key molecular species in ring-closing metathesis.
Article
Chemistry, Multidisciplinary
Zhenjie Su, Pathan Mosim Amin, Shaozhong Wang
Summary: This paper presents a Au(I)-catalyzed ring-closing alkyne-carbonyl metathesis protocol for efficient synthesis of γ-butenolides. The reaction exhibits high atom economy, substrate flexibility, and functional group tolerance, and can be used to synthesize various naturally occurring butenolide-type compounds.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Andrea Ojeda-Porras, Remi Aouzal, Claire Wilson, Joelle Prunet
Summary: Two synthetic routes for the ABC tricycle of Taxol are presented, both involving a relay ring-closing metathesis reaction to form the central B ring. In the first approach, the extender arm is positioned on the A ring, while the C ring bears the relay tether in the second route. Despite the efficient synthesis of metathesis precursors with diverse extender arms, the crucial metathesis reactions failed to yield the target compounds in all cases.
Article
Chemistry, Physical
Felix Ziegler, Thomas Roider, Markus Pyschik, Christian P. Haas, Dongren Wang, Ulrich Tallarek, Michael R. Buchmeiser
Summary: The study demonstrates the efficient use of a 2(nd)-generation Hoveyda-Grubbs-type catalyst immobilized inside mesoporous silica for selective macro(mono)cyclization (MMC) of an alpha,omega-diene under spatially confined and continuous-flow conditions. By analyzing reaction mixtures through NMR and MALDI-TOF-MS, the study identifies the effects of confinement on olefin metathesis pathways and determines conditions for achieving high MMC selectivity. The research also highlights the preference for ring-closing metathesis of monomers and backbiting from dimers and trimers under confinement, leading to a high MMC selectivity of 60%.
Article
Chemistry, Multidisciplinary
Myron Triantafyllakis, Sam Alexander, Sophie Woolford, Claire Wilson, J. Stephen Clark
Summary: The fully functionalized A-F fragment of the Pacific ciguatoxin CTX3C has been synthesized using specific reaction sequences and synthesis routes, achieving the construction of a multi-ring system and the introduction of functional groups.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Ervin Kovacs, Bence Balterer, Nguyen Anh Duc, Gyorgyi Szarka, Michael C. Owen, Attila Domjan, Bela Ivan
Summary: A large number of organic solvents contaminate the environment on a daily basis worldwide. This study demonstrates that benzotrifluoride can be used as a suitable solvent for olefin metathesis reactions, providing high yields and similar or even higher reaction rates compared to dichloromethane.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Organic
Frank Schmidt, Aparna Viswanathan Ammanath, Friedrich Goetz, Martin E. Maier
Summary: A new synthesis route was established for the macrolactone antibiotic berkeleylactone A. The synthesis involved ring-closing alkyne metathesis (RCAM) of an ester substrate with 1-propynyl termini. The carboxylic part of the substrate was assembled using alkyne chemistry, while the alcohol part of the ester was synthesized through propylene oxide opening and triple bond migration reactions. After successful RCAM, the triple bond was selectively hydrogenated and the 4,5-diol was oxidized to obtain the desired derivative. The thioether formation and reduction of the 8,9-double bond were also achieved. However, the antimicrobial activity of the analog was found to be slightly reduced.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Sambasivarao Kotha, Deepshikha Singh, Vijayalakshmi Bandi
Summary: An efficient and short synthetic sequence for highly functionalized urazole derivatives has been reported. N-substituted-1,2,4-triazoline-3,5-dione (TAD) was used as a versatile synthetic reagent. Simple reactions including allylation, ring-closing metathesis, and hydrogenation were successfully employed to construct oxygenated urazole derivatives, which may have implications in medicinal chemistry and organic synthesis.
Article
Chemistry, Physical
Lantao Liu, Fangyuan Cheng, Chenxiang Meng, An-An Zhang, Mingliang Zhang, Kai Xu, Naoki Ishida, Masahiro Murakami
Summary: A Pd-catalyzed chemo-, regio-, and enantioselective ring-closing/ring-opening cross coupling reaction has been developed with diverse aryl halide-tethered alkenes and benzocyclobutenols as substrates. This method provides a convenient approach to chiral 2,3-dihydrobenzofurans with excellent enantioselectivities, and has been applied in the concise synthesis of analogues of cannabinoid receptor 2 agonists.
Review
Chemistry, Multidisciplinary
Olga O. Sokolova, John F. Bower
Summary: This review summarizes synthetic developments reported from 1987 to 2019 that exploit C-C single bond cleavage of cyclopropylamine-based systems. The synthetic and mechanistic aspects of key methodologies are highlighted, and examples where aminocyclopropanes are exploited as key intermediates in multistep synthesis are also discussed. The review encompasses cases where aminocyclopropanes participate in polar reactions, pericyclic processes, radical-based reactions, and C-C bond activations.
Review
Chemistry, Multidisciplinary
Lauren G. O'Neil, John F. Bower
Summary: Classical amination methods involve the reaction of a nitrogen nucleophile with an electrophilic carbon center; however, in recent years, umpoled strategies have gained traction where the nitrogen source acts as an electrophile. A wide range of electrophilic aminating agents are now available, and these underpin a range of powerful C-N bond-forming processes. In this Review, we highlight the strategic use of electrophilic aminating agents in total synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jamie A. Cadge, John F. Bower, Christopher A. Russell
Summary: A combined theoretical and experimental investigation revealed an unusual mechanism of aryl iodide oxidative addition to gold complexes. The comparison between gold and palladium demonstrated significant differences in reaction rates and mechanisms, suggesting that gold could potentially facilitate a broad range of new or complementary transformations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Changcheng Jing, Joshua J. Farndon, John F. Bower
Summary: Dearomatization reactions enable the direct synthesis of structurally complex sp(3)-rich molecules from readily available flat precursors. Recent methodological efforts have focused on methods that introduce C-N bonds due to the privileged position of nitrogen in drug discovery. Several new processes now allow the direct preparation of sp(3)-rich amino-containing building blocks and scaffolds.
Article
Chemistry, Organic
Timothy P. Aldhous, Raymond W. M. Chung, Andrew G. Dalling, John F. Bower
Summary: This review presents recent intermolecular enantioselective Murai-type alkene hydroarylation methodologies and the mechanisms by which they proceed, providing an efficient way to achieve enantioselective hydroarylations of alkenes with benzylic stereocenters.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Guilherme A. M. Jardim, Renato L. de Carvalho, Mateus P. Nunes, Luana A. Machado, Leandro D. Almeida, Karim A. Bahou, John F. Bower, Eufranio N. da Silva Junior
Summary: Metal catalyzed C-H functionalization is widely used in organic chemistry for selective functionalization. Understanding the synthesis of transition metal Cp-type catalysts is crucial for modifying the catalyst structure for different applications.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Olga O. Sokolova, John F. Bower
Summary: An enantioselective (3+1+2) cycloaddition reaction triggered by carbonylative C-C bond activation of cyclopropanes is achieved using an endo-directing group strategy. This reaction represents a rare example where C-C bond oxidative addition determines the enantiomeric outcome, and it is the first time this has been achieved within the context of a multicomponent reaction design.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Adam D. J. Calow, David Dailler, John F. Bower
Summary: Under Rh-catalyzed conditions, secondary amines and anilines serve as directing groups, enabling regioselective C-C bond activation of nonactivated cydopropanes. The resulting amino-stabilized rhodacydes undergo carbonylative C-N bond formation to yield challenging seven- and eight-membered lactams, exploiting the rare oxidative addition of C-C bonds of nonactivated cyclopropanes in reaction design.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Jamie A. Cadge, Paul J. Gates, John F. Bower, Christopher A. Russell
Summary: This research reports a newly discovered gold(III) metallafluorene complex that can be used for the synthesis of stable 9-fluorenone products through migratory insertion of CO. This finding expands the potential of using gold chemistry for product synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Changcheng Jing, Benjamin T. Jones, Ross J. Adams, John F. Bower
Summary: Unique examples of aza-Heck-based C(sp3)-H functionalization cascades are described, where alkyl-Pd(II) intermediates generated from the aza-Heck-type cyclization of N-(pentafluorobenzoyloxy)carbamates undergo C(sp(3))-H palladation to form cyclopropanes. The key factors controlling the site selectivity of the cyclopropanation process have been elucidated, enabling selective access to a wide range of ring- or spiro-fused systems.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Olga O. Sokolova, Andrew G. Dalling, John F. Bower
Summary: This Account focuses on C-C bond activation based methodologies using minimally activated cyclopropanes, which allow for the atom economical assembly of complex scaffolds.
Article
Chemistry, Multidisciplinary
Samuel C. Scott, Jamie A. Cadge, Grace K. Boden, John F. Bower, Christopher A. Russell
Summary: We presented a Au-I complex of a hemi-labile (C boolean AND N) N-heterocyclic carbene ligand which can catalyze the oxidative addition of aryl iodides. Extensive computational and experimental investigations were performed to confirm and rationalize the oxidative addition process. The application of this initiation mode led to the first examples of exogenous oxidant-free Au-I/Au-III catalyzed 1,2-oxyarylations of ethylene and propylene. These challenging yet powerful processes establish these commodity chemicals as nucleophilic-electrophilic building blocks in catalytic reaction design.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yuxiang Zhu, Matthew J. S. Smith, Wenbin Tu, John F. Bower
Summary: TFA promotes deprotection of O-Ts activated N-Boc hydroxylamines, leading to aminofunctionalization-based polycyclizations of tethered alkenes. The method enables a range of intramolecular alkene anti-1,2-difunctionalizations, including diamination, amino-oxygenation, and amino-arylation. It offers a predictable platform for accessing diverse C(sp(3))-rich polyheterocycles relevant to medicinal chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Matthew J. S. Smith, Wenbin Tu, Craig M. Robertson, John F. Bower
Summary: This article introduces an aminative cyclization reaction under acidic conditions, which is triggered by the deprotection of BocNR(OSO2R) reagents and carried out on alkenes equipped with pendant nucleophiles. The method offers flexibility in terms of choosing nucleophiles, alkenes, and cyclization modes, and enables the construction of consecutive stereocenters under operationally simple conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Phillippa Cooper, Andrew G. Dalling, Elliot H. E. Farrar, Timothy P. Aldhous, Simon Grelaud, Eleanor Lester, Lyman J. Feron, Paul D. Kemmitt, Matthew N. Grayson, John F. Bower
Summary: The Ir-catalyzed alkene hydroarylation allows for the efficient synthesis of quaternary benzylic centers, and the structural features of the ligand play a crucial role in the reaction efficiency.
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.
