Chem

Journal: Chem

Publisher

Cell Press

ISSN

2451-9294
2451-9308

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Publications 1 - 10 of 25

Ligand-enabled override of the memory effect in Rh-catalyzed asymmetric Suzuki reactions
Liu, Ke; Egea-Arrebola, David; Ardkhean, Ruchuta; et al. (2025)
Chem
Chiral non-racemic allylic species are key building blocks for many carbon-containing molecules, including pharmaceuticals and polymers. Metal-catalyzed asymmetric additions of nucleophiles to allylic species undergo different pathways depending on the metal and nucleophile combination, hindering the development of useful addition reactions with aromatic nucleophiles. We report an asymmetric cross-coupling method between aryl boronic acids and linear allylic phosphates to give branched allylic products. This Suzuki-type reaction overcomes the “memory effect” in Rh catalysis, enabling an overall SN2′ transformation by rate-determining reductive elimination and forming a new stereogenic center adjacent to a terminal vinyl moiety. The method tolerates preexisting stereogenic centers, allowing for synthetic strategies where drugs and natural products are elaborated via diastereoselective allylic arylations. The method is used, as the catalyst-controlled stereochemistry-setting step, in an iterative strategy to give arrays of aryl-substituted contiguous stereogenic centers. This approach will complement existing catalyst-controlled stereoselective methods for forming C–C bonds.
Mass Photometry of Membrane Proteins
Olerinyova, Anna; Sonn-Segev, Adar; Gault, Joseph; et al. (2021)
Chem
Integral membrane proteins (IMPs) are biologically highly significant but challenging to study because they require maintaining a cellular lipid-like environment. Here, we explore the application of mass photometry (MP) to IMPs and membrane-mimetic systems at the single-particle level. We apply MP to amphipathic vehicles, such as detergents and amphipols, as well as to lipid and native nanodiscs, characterizing the particle size, sample purity, and heterogeneity. Using methods established for cryogenic electron microscopy, we eliminate detergent background, enabling high-resolution studies of membrane-protein structure and interactions. We find evidence that, when extracted from native membranes using native styrene-maleic acid nanodiscs, the potassium channel KcsA is present as a dimer of tetramers—in contrast to results obtained using detergent purification. Finally, using lipid nanodiscs, we show that MP can help distinguish between functional and non-functional nanodisc assemblies, as well as determine the critical factors for lipid nanodisc formation. © 2020 Elsevier Inc.
Chemical education in digital chemistry
Fung, Fun Man; Lederbauer, Magdalena; Choo, Yvonne S.L.; et al. (2024)
Chem
In this digital age where machine learning has won the Nobel Prizes in both Physics and Chemistry, it is ever more important to give chemistry students an educational advantage that will enable them to use the tools of artificial intelligence and machine learning to enhance both their study experience and their future research. In this Voices article, chemistry education and research experts gather to share their implementation and utilization of these data-driven tools in classes and in labs.
High-Throughput Multi-parametric Imaging Flow Cytometry
Rane, Anandkumar S.; Rutkauskaite, Justina; deMello, Andrew J.; et al. (2017)
Chem
A roadmap toward the synthesis of life
Kriebisch, Christine M.E.; Bantysh, Olga; Baranda Pellejero, Lorena; et al. (2025)
Chem
The synthesis of life from non-living matter has captivated and divided scientists for centuries. This bold goal aims at unraveling the fundamental principles of life and leveraging its unique features, such as its resilience, sustainability, and ability to evolve. Synthetic life represents more than an academic milestone—it has the potential to revolutionize biotechnology, medicine, and materials science. Although the fields of synthetic biology, systems chemistry, and biophysics have made great strides toward synthetic life, progress has been hindered by social, philosophical, and technical challenges, such as vague goals, misaligned interdisciplinary efforts, and incompletely addressing public and ethical concerns. Our perspective offers a roadmap toward the synthesis of life based on discussions during a 2-week workshop with scientists from around the globe.
Efficient electrochemical conversion of nitric oxide to ammonia using a porous nickel catalyst in a membrane electrode assembly electrolyzer
Singh-Morgan, Amrita; Trösch, Kim; Weinfurter, Anna; et al. (2025)
Chem
The electrochemical synthesis of ammonia presents a promising pathway to decarbonize and electrify the production of the world's second-largest commodity chemical. Among potential reactants, NOₓ gases stand out owing to their favorable thermodynamics, advantageous kinetics, and availability from both combustion emissions and nitrogen-fixation processes, such as plasma-induced atmospheric nitrogen oxidation. However, the typically low concentration of NOₓ in these sources poses significant challenges for electrochemical performance, particularly due to limitations in reactant mass transport. In this work, we report on the use of a porous nickel catalyst in a membrane electrode assembly (MEA) electrolyzer to enable the direct use of a dilute nitric oxide (NO) feed. The rational optimization of reactant mass transport led to the attainment of maximum values of NO-to-NH₃ single-pass conversion of 93%, faradaic efficiency for ammonia of 92%, and ammonium production rate of 556 μmol/h⋅cm².
The AMI-isonitrile ligation 2.0: Fast, selective, and pH sensitive
Biedermann, Maurice P.; Markos, Athanasios; Warm, Ian; et al. (2025)
Chem
The bioorthogonal ligation between isonitriles and azomethine imines (AMIs)—the AMI-isonitrile ligation—combines exquisite chemoselectivity with a stable ligation product, a small molecular reporter, and a pH-dependent rate. In this work, we tailored the modular structure of the dipolar AMI to increase Brønsted basicity and electrophilicity. These additive structural modifications increased the ligation rate by more than two orders of magnitude to 14 M−1s−1 at pH 7, 140 M−1s−1 at pH 6, and >1,000 M−1s−1 at pH 5. The faster reaction rate at lower pH values allowed for the preferential labeling of live cells at acidic versus neutral pH. This environmental sensitivity paves the way for in vivo targeting of acidic milieus, such as tumors.
Electrochemical ⁶Li isotope enrichment based on selective insertion in 1D tunnel-structured V₂O₅
Carrillo, J. Luis; Ezazi, Andrew A.; Perez-Beltran, Saul; et al. (2025)
Chem
The renaissance of nuclear energy has generated substantial demand for ⁶Li as a target for nuclear bombardment reactions to produce tritium fuel in breeder reactors. Conventional isotope separation methods utilize differential solubility in mercury amalgams, which pose performance, toxicity, and sustainability concerns. Here, we show that hybrid capacitive deionization wherein Li ions are inserted from aqueous media within the 1D tunnels of a metastable polymorph, ζ-V₂O₅, can be used to selectively sequester ⁶Li ions. An enrichment factor of ca. 57‰ is achieved. X-ray scattering, spectroscopy, and operando spectromicroscopy studies indicate that Li ions are sequestered within 1D tunnels of ζ-V₂O₅ through faradaic processes. ⁶Li and ⁷Li ions are found to migrate at different rates because of subtly different coordination environments. The results illustrate that ζ-V₂O₅ can be utilized as a discriminating host to selectively sequester and enrich ⁶Li from natural abundance precursor flow streams and suggest a distinctive mode of achieving viable isotope separation.
Metal-organic frameworks for fast electrochemical energy storage: Mechanisms and opportunities
Hong, Chulgi Nathan; Crom, Audrey B.; Feldblyum, Jeremy I.; et al. (2023)
Chem
Metal-organic frameworks (MOFs) have the potential to rival or even surpass traditional energy storage materials. However, realizing the full potential of MOFs for energy storage with competitive performance at industrially relevant scales requires a unified approach from electrochemists and synthetic and material chemists. This review aims to bridge the knowledge gap between electrochemists and scientists working in the field of MOFs. We introduce the basic concepts of energy storage devices, including charge storage mechanisms, and highlight the interconnected nature of the material, electrode, and cell parameters that can significantly affect the metrics of energy storage devices. The design principles of MOFs are then discussed in relation to the parameters that must be considered for their use in fast electrochemical energy storage devices. Finally, we discuss the characterization techniques necessary to unveil the charge storage mechanism in MOF-containing energy storage devices, as this understanding is critical to drive their rational design.
Catalysis Catalyst: A step forward for PVC manufacture from natural gas
Zichittella, Guido; Ceruti, Amedeo; Guillén Gosálbez, Gonzalo; et al. (2022)
Chem
Guido Zichittella studied chemical engineering at Politecnico di Milano (BSc) and at ETH Zurich (MSc) and received his PhD for work on direct functionalization of light alkanes under the supervision of Prof. Dr. Perez-Ramirez. Amedeo Ceruti received his MSc from the Technical University of Munich. His research interests include sustainable process and energy systems. Gonzalo Guillen-Gosalbez holds the Chair of Chemical Systems Engineering at ETH Zurich. His research interests focus on sustainable process systems engineering. Javier Perez-Ramirez holds the Chair of Catalysis Engineering at ETH Zurich. His research pursues the nanoscale design of catalytic materials enabling the transition toward sustainable chemical and energy production.

Publications 1 - 10 of 25

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