Article
Chemistry, Physical
Jose B. Roque, Tyler P. Pabst, Paul J. Chirik
Summary: The use of bis(silylene)pyridine cobalt(III) dihydride boryl as a precatalyst enables efficient hydrogen isotope exchange reactions, including deuterium incorporation at sterically hindered sites and high chemoselectivity towards aryl halides.
Review
Chemistry, Organic
Sanjeev Kumar, Saiprasad Nunewar, Srilekha Oluguttula, Srinivas Nanduri, Vinaykumar Kanchupalli
Summary: In the past two decades, transition metal-catalyzed C-H functionalization followed by annulations with various coupling partners has attracted much attention in organic synthesis. Rh(iii) or Ir(iii) catalyzed regioselective C-H functionalization followed by the cyclization of diverse arenes with metal carbene precursors has become a highly investigated research field recently. This review aims to provide a comprehensive essay on the Rh(iii)/Ir(iii) catalyzed C-H functionalizations/annulations via carbene migratory insertion, with a focus on diverse metal carbene precursors with arenes/alkenes reported so far.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Review
Chemistry, Organic
Pan Yannian, Qin Xiao, Yuan Chengkai, Lu Yi
Summary: Cp*Rh(III) catalysts exhibit excellent performance in the inert C-H bond functionalization field due to their high activity and stability under mild conditions. However, there is a limited number of studies on ligands in the Cp*Rh(III) catalytic system due to the constraints of Rh(III) coordination orbitals. Our research group has recently focused on ligand-promoted C-H bond functionalization with high activity and selectivity. This review systematically summarizes the related works of Cp*Rh(III)-catalyzed C-H bond functionalization, including both symmetric and asymmetric C-H activation. The role of ligands in the Cp*Rh(III) catalytic system is discussed and some reaction mechanisms are briefly described.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Yuki Nagashima, Shiho Ishigaki, Jin Tanaka, Ken Tanaka
Summary: The research reveals that the (CpRh)-Rh-E(III) complex stabilizes key transition states in oxidative C-H bond functionalization reactions through strong orbital interactions, and the CpRh(III) complex is more stable in the reductive elimination step for sterically demanding substrates.
Article
Chemistry, Multidisciplinary
Anil Kumar, Kandikere Ramaiah Prabhu
Summary: A new [5+1] annulation reaction has been discovered, leading to the efficient synthesis of valuable compounds with unique chemical structures in a single step. The process demonstrates broad substrate scope and good functional group tolerance.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Longkun Chen, Mingshuai Zhang, Meichen Liu, Zhuoyuan Liu, Yuetong Qiu, Zhilai Zhang, Fuchao Yu, Jiuzhong Huang
Summary: In this study, an efficient Rh(III)-catalyzed selective mono- and dual-C-H bond functionalization/cyclization with iodonium ylide as the sole coupling partner was demonstrated. Fused benzodiazepine skeletons were obtained in excellent yields, providing an improved approach to dual C-H unsymmetrical functionalization.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Physical
Zachary J. Garlets, Yannick T. Boni, Jack C. Sharland, Randall P. Kirby, Jiantao Fu, John Bacsa, Huw M. L. Davies
Summary: The synthesis and evaluation of six C-4-symmetric bowl-shaped dirhodium tetracarboxylate catalysts are described, and these catalysts demonstrate highly site-selective, diastereoselective, and enantioselective C-H functionalization reactions through donor/acceptor carbene-induced C-H insertions.
Article
Chemistry, Inorganic & Nuclear
Alen Bjelopetrovic, Dajana Barisic, Marina Juribasic Kulcsar, Ivan Halasz, Manda Curic, Stipe Lukin
Summary: We report the mechanochemically-induced deuteration of aromatic C(sp(2))-H bonds activated by Pd at ambient temperature without the need for solvents. Deuterium was sourced from cysteine-d(4) to obtain mono- or dideuterated products from different aromatic palladacycles. Besides the high deuteration yields, we provide a detailed view of the reaction course in the solid state through time-resolved in situ Raman monitoring and DFT calculations. The obtained knowledge could lead to the broader application of this methodology for the deuteration of organic compounds.
INORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Physical
Nghia Le, Natalie L. Chuang, Clay M. Oliver, Andrey V. Samoshin, Jack T. Hemphill, Kelsey C. Morris, Stephen N. Hyland, Hairong Guan, Charles Edwin Webster, Timothy B. Clark
Summary: The metal-catalyzed C-H borylation reaction is a valuable method for incorporating boronate esters into organic substrates. However, a comprehensive study of the mechanism has not been reported so far. In this study, both experimental and computational approaches were used to investigate the catalytic mechanism of amine-directed C(sp(2))-H borylation. The results revealed the absence of isotope effects at the functionalized C-H bond and suggested the rate-determining step to be the reassociation of pinacolborane. Additionally, the role of pinacolborane as an additive was examined and found to enhance the reaction rate by acting as an autocatalyst.
Article
Chemistry, Multidisciplinary
Kristers Ozols, Shunsuke Onodera, Lukasz Wozniak, Nicolai Cramer
Summary: The study presents a method for highly enantioselective intermolecular carboaminations of alkenes through C-H activation catalyzed by high-valent cyclopentadienyl cobalt complexes. This method converts widely available acrylates and bicyclic olefins into enantioenriched isotyrosine derivatives and amino-substituted bicyclic scaffolds under very mild conditions. The reactivity outlined in this research is unique to the (CpCoIII)-Co-x complexes and complements the reactivity of 4d- and 5d- precious-metal catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Zeng-Hui Lin, Yu-Fei Yao, Cheng-Pan Zhang
Summary: Deuteration of arylthianthren-S-ium triflates with CD3OD or CD3OD/CD3COCD3 in the presence of Cs2CO3 by palladium catalysis or photoirradiation allows for the convenient synthesis of deuterated arenes in good yields. The Pd-catalyzed reaction generally gives better yields than the photoinduced deuteration, but exceptions exist. These reactions highlight eco-friendly conditions, simplicity, inexpensive deuterium sources, good functional group tolerance, and a range of substrates. This protocol provides a high selectively formal aromatic C-H deuteration for efficient deuterium labeling of multifunctionalized arenes and drug molecules.
Article
Chemistry, Organic
Min Seo Park, Kyeongwon Moon, Harin Oh, Ji Yoon Lee, Prithwish Ghosh, Ju Young Kang, Jung Su Park, Neeraj Kumar Mishra, In Su Kim
Summary: The Rh(III)-catalyzed C-H functionalization and subsequent intramolecular cyclization between azobenzenes and vinylene carbonate leads to the formation of different compounds, such as (2H)-indazoles or dihydrocinnolin-4-ones. Vinylene carbonate surprisingly acts as an acetaldehyde or acetyl surrogate, enabling [4 + 1] or [4 + 2] annulation reaction. This transformation stands out for its mild reaction conditions, simplicity, and excellent functional group compatibility.
Article
Chemistry, Multidisciplinary
Ruihan Wang, Yidong Wang, Ruiqi Ding, Parker B. Staub, Christopher Z. Zhao, Peng Liu, Yi-Ming Wang
Summary: A newly-developed cationic cyclopentadienyliron dicarbonyl complex enables the conversion of propylene to its allylic C-C bond coupling products under catalytic conditions. This approach is also applicable to the allylic functionalization of simple alpha-olefins with distinctive branched selectivity. Experimental and computational studies reveal the allylic deprotonation of the metal-coordinated alkene as the turnover-limiting step and provide insights into the multifaceted roles of the newly designed ligand in promoting allylic C-H functionalization with enhanced reactivity and stereoselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Zachary J. Garlets, Elizabeth M. Yuill, Alice Yang, Qingmei Ye, Wei Ding, Christopher Wood, Junying Fan, Nicolas Lucien Cuniere, Chris Sfouggatakis
Summary: The use of deuterium in the pharmaceutical industry has been expanding in recent years. This is due to the efforts of medicinal chemists to design compounds with improved metabolic profiles and increase the success rate of compounds in clinical trials. However, this expansion poses challenges for process and analytical chemists in tracking isotopologues and isotopomers to ensure the quality of intermediates and active pharmaceutical ingredients.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2023)
Article
Multidisciplinary Sciences
Da Zhao, Roland Petzold, Jiyao Yan, Dieter Muri, Tobias Ritter
Summary: Tritium labelling is a critical tool for pharmacokinetic and pharmacodynamic studies, and tritium gas is preferred for labelling due to its high isotopic purity. While heterogeneous catalysts like palladium supported on carbon are commonly used for tritiation reactions, their reaction mechanism can result in the reduction of other functional groups present in pharmaceuticals.
Article
Chemistry, Multidisciplinary
Dukhan Kim, Melanie S. Sanford, Thomas P. Vaid, Anne J. McNeil
Summary: The nonaqueous redox-matched flow battery (RMFB) stores charge on redox-active moieties tethered to insoluble polymer beads, transferring charge between electrodes and beads via soluble mediators with matching redox potentials. This approach enables high energy density and prevents crossover of active material.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Liam S. Sharninghausen, Sean Preshlock, Stephen T. Joy, Mami Horikawa, Xia Shao, Wade P. Winton, Jenelle Stauff, Tanpreet Kaur, Robert A. Koeppe, Anna K. Mapp, Peter J. H. Scott, Melanie S. Sanford
Summary: This report presents a copper-mediated radiocyanation method for aryl halides that can be applied to complex molecules. The reaction demonstrates a broad tolerance to various functional groups, including unprotected amino acids, making it possible to introduce [C-11]CN into specific sites of peptides. The use of a diamine-ligated copper(I) mediator is essential for achieving high radiochemical yield under mild conditions, while minimizing unwanted side reactions. The method has been successfully scaled and automated for the synthesis of radiolabeled peptides, and has been applied to the preparation of [C-11]cyano-NOP for biodistribution studies using positron emission tomography.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Matthew R. Lasky, Tolani K. Salvador, Sukrit Mukhopadhyay, Matthew S. Remy, Thomas P. Vaid, Melanie S. Sanford
Summary: This report describes the development of a photochemical method for C(sp(2))-H pyridination that leverages the photoexcitation of electron donor-acceptor (EDA) complexes. The reaction results in aryl radical cation intermediates that can be trapped with pyridine nucleophiles under aerobic conditions. This approach eliminates the need for an exogenous photocatalyst and is cost-effective.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Thomas P. Vaid, Monique E. Cook, Jessica D. Scott, Marino Borjesson Carazo, Jonathan Ruchti, Shelley D. Minteer, Matthew S. Sigman, Anne J. McNeil, Melanie S. Sanford
Summary: Cyanopyridines and cyanophenylpyridines were investigated as anolytes for nonaqueous redox flow batteries. Adding a phenyl group can improve the stability of the radical anions and voltage efficiency, with 3-CN-6-PhPy and 3-CN-4-PhPy showing the most promising results.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Inorganic & Nuclear
Liana Ribeiro Gouveia, Elon A. Ison
Summary: A new family of air-stable Re and Mn complexes with bidentate NNS ligands was introduced, and their performance and reaction mechanism as aldehyde hydrogenation catalysts were studied.
Review
Chemistry, Multidisciplinary
Naish Lalloo, Conor E. Brigham, Melanie S. Sanford
Summary: Transition-metal-catalyzed decarbonylative coupling reactions using carboxylic acid derivatives as electrophiles have the advantages of abundant and inexpensive reactants. This Account highlights the development of base-free decarbonylative coupling reactions catalyzed by group 10 metals and discusses the catalyst design guided by stoichiometric organometallic studies. The article also discusses the challenges and future directions in this field.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Review
Chemistry, Multidisciplinary
Ryan Walser-Kuntz, Yichao Yan, MatthewS. Sigman, Melanie S. Sanford
Summary: Redox flow batteries are a promising technology for energy storage, and the design of optimal molecules as energy storage materials is crucial. These molecules should undergo reversible redox reactions at high or low potentials for oxidation and reduction, respectively, in addition to being highly soluble and stable during electrochemical cycling. The Account describes the design and optimization process of organic molecules, using aminocyclopropenium-based catholytes as an example.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
E. William Webb, Kevin Cheng, Jay S. Wright, Jocelyn Cha, Xia Shao, Melanie S. Sanford, Peter J. H. Scott
Summary: Radiocyanation is an attractive and complementary strategy for incorporating carbon-11 into radiotracer targets. This approach utilizes a Cu-11CN complex to capture aryl radical intermediates, enabling rapid and mild radiocyanation. Examples include the reaction of CuI with aryldiazonium salt and visible-light photocatalysis of aryl iodides, both followed by coupling with Cu-11CN to access challenging radiocyanated products.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Applied
Tanpreet Kaur, Xia Shao, Mami Horikawa, Liam S. Sharninghausen, Sean Preshlock, Allen F. Brooks, Bradford D. Henderson, Robert A. Koeppe, Alexandre F. DaSilva, Melanie S. Sanford, Peter J. H. Scott
Summary: This report compares four different routes for the clinical-scale radiosynthesis of the kappa-opioid receptor antagonist [11C]LY2795050. Palladium-mediated radiocyanation and radiocarbonylation of an aryl iodide precursor, as well as copper-mediated radiocyanation of an aryl iodide and an aryl boronate ester, have been investigated. Full automation of all four methods is reported, each of which provides [11C]LY2795050 in sufficient radiochemical yield, molar activity, and radiochemical purity for clinical use. The advantages and disadvantages of each radiosynthesis method are compared and contrasted.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2023)
Article
Chemistry, Inorganic & Nuclear
Jonathan R. Hall, Isaac M. Blythe, Liam S. Sharninghausen, Melanie S. Sanford
Summary: This report describes the Cu-catalyzed directed fluoroalkylation of aryl bromide substrates using N heterocyclic carbene copper(I) fluoroalkyl complexes and aryl halides bearing ortho-directing groups such as pyridine, pyrazole, oxazoline, imine, and ester. These directing groups significantly enhance the reactivity of aryl bromides and chlorides with (IPr)CuI-fluoroalkyl complexes, leading to the formation of aryl-fluoroalkyl coupling products.
Article
Chemistry, Inorganic & Nuclear
Abebu A. Kassie, Ila Y. Castro De la Torre, Matthew S. Remy, Sukrit Mukhopadhyay, Jeff Kampf, Fengrui Qu, Melanie S. Sanford
Summary: This manuscript investigates the impact of different metals (ruthenium, iron, and manganese) on the PNP pincer complex-catalyzed dehydrogenative coupling reaction. The study reveals that the structures and reactivities of the intermediates vary depending on the metal used. It is found that the manganese pincer complex is an effective catalyst for the conversion of formamides and alcohols to carbamates under specific conditions.
Article
Chemistry, Inorganic & Nuclear
Ellen Y. Aguilera, En-Chih Liu, Scott M. Thullen, Melanie S. Sanford
Summary: This study describes the Pd-catalyzed C(sp3)-H functionalization of a tropane derivative, resulting in functionalization at two (beta/gamma) or three (beta/gamma/beta) different positions on the alicyclic amine core. The reaction involves initial dehydrogenation to generate alkene products, which can further react to form a Pd(I) alkene-bridged dimer. Functionalization of this dimer leads to beta/gamma/beta-functionalized allylic arylation and allylic acetoxylation products.
Article
Chemistry, Inorganic & Nuclear
Ellen Y. Aguilera, En-Chih Liu, Scott M. Thullen, Melanie S. Sanford
Summary: This study describes the Pd-catalyzed C(sp(3))-H functionalization of a tropane derivative, resulting in products with functionalization at two or three different sites on the alicyclic amine core. The reaction involves dehydrogenation to generate an alkene product, which can further react to form a Pd(I) alkene-bridged dimer. Functionalization of this dimer produces ss/./ss-functionalized allylic arylation and allylic acetoxylation products.
Meeting Abstract
Radiology, Nuclear Medicine & Medical Imaging
Liam Sharninghausen, Sean Preshlock, Stephen Joy, Anna Mapp, Melanie Sanford, Peter Scott
NUCLEAR MEDICINE AND BIOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Yichao Yan, Ryan Walser-Kuntz, Melanie S. Sanford
Summary: In this study, phenoxazine derivatives with N-methyl, N-isopropyl, and N-cyclopropenium substituents were synthesized and studied as catholytes for nonaqueous redox flow batteries. The derivatives showed high redox potentials and stable electrochemical cycling.
ACS MATERIALS LETTERS
(2022)
