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The Role of the Journal Impact Factor in Chemistry Research
Get PDFThe journal impact factor (JIF) is a skewed metrics whose value is dictated by just a few highly cited articles. Therefore, the use of the JIF to evaluate journals, scholars, or research institutes is flawed. Still, the JIF continues to play a central role in evaluating scholarship in chemistry, the most reluctant amid scientific disciplines to embrace the principles of open science. This study investigates the origins of this social behavior, and suggests avenues to improve scholarly communication in the chemical sciences following the example of the life sciences
Addition Reactions to Unsaturated Fatty Acids: A Theoretical Study about Mechanisms and Stereochemistry: Chemical Education
No full textAfter a short introduction about fatty acids, the article refers to an unclear statement by Gibson et al. about the kind and number of isomeric products formed by addition of hypochloric acid to palmitoleic acid and linoleic acid. A theoretical approach with detailed mechanistic and stereochemical considerations will lead the reader to the solution of the problem
Improving Enzyme Fitness with Machine Learning
Get PDFThe combinatorial composition of proteins has triggered the application of machine learning in enzyme engineering. By predicting how protein sequence encodes function, researchers aim to leverage machine learning models to select a reduced number of optimized sequences for laboratory measurement with the aim to lower costs and shorten timelines of enzyme engineering campaigns. In this review, we will highlight successful algorithm-aided protein engineering examples, including work carried out within the NCCR Catalysis. In this context, we will discuss the underlying computational methods developed to improve enzyme properties such as enantioselectivity, regioselectivity, activity, and stability. Considering the rapid maturing of computational techniques, we expect that their continued application in enzyme engineering campaigns will be key to deliver additional powerful biocatalysts for sustainable chemical synthesis
New Frontiers in Alkali-Metal Nickelates
Get PDFRecent advances in heterobimetallic chemistry have revealed the potential for mixed-metal systems to facilitate reactions that are unattainable with their single-metal components. This perspective explores the pairing of nickel(0) complexes with organo-alkali-metal reagents, which yield highly reactive alkali-metal nickelates. These previously underexplored systems have re-emerged as a promising area of research, with recent studies uncovering their unique bonding and structural motifs. Furthermore, the discovery of nickelates as potential intermediates in cross-coupling reactions has provided the foundation for the development and mechanistic understanding of stoichiometric and catalytictransformations
Mechanistic Views on First-row Earth-Abundant Transition Metal Catalyzed Ullmann-type O-Arylation Reactions
Get PDFTransition metal-catalyzed reactions have attracted much attention in synthetic organic chemistry due to their important role in the formation of C-heteroatom bonds. Ullmann coupling has risen in prominence in recent decades owing to its utilization in the synthesis of biaryl ethers found in a wide range of natural products together with biologically essential molecules, including antibiotics and major industrial polymers. In this article we provide the current understanding of the theoretical aspects of the underlying mechanism of the Ullmann-type O-arylation reaction
Improvements in Resolution of ¹H NMR of solids
Get PDFMagic angle spinning (MAS) in 1H NMR has allowed progress from featureless spectra in static samples to linewidths of a few hundreds of Hertz for powdered solids at the fastest spinning rates available today (100-150 kHz). While this is a remarkable improvement, this level of resolution is still limiting to the widespread use of 1H NMR for complex systems. This review will discuss two recent alternative strategies that have significantly improved 1H resolution, when combined with fast MAS. The first is based on anti-z-COSY, a 2D experiment originally used for J decoupling in liquids, which removes residual broadening due to splittings caused by imperfect coherent averaging of MAS. The second strategy is to obtain pure isotropic proton (PIP) spectra in solids, by parametrically mapping any residual broadening due to imperfect averaging into a second dimension of a multidimensional correlation spectrum.  
Modular Cloning by Golden Gate Assembly and Possible Application in Pathway Design
Get PDFPreparation of expression vectors using conventional cloning strategies is laborious and not suitable for the design of metabolic pathways or enzyme cascades, which usually requires the preparation of a vector library to identify productive clones. Recently, Modular Cloning as a novel cloning technique in synthetic biology has been developed. Modular Cloning relies on Golden Gate assembly and supports preparation of individual expression vectors in one-step and one-pot reactions, thus allowing rapid generation of vector libraries. A number of Modular Cloning toolkits for specific applications has been established, providing a collection of distinct genetic elements such as promoters, ribosome binding sites and tags, that can be combined individually in one-step using defined fusion sites. Modular Cloning has been successfully applied to generate various strains for producing value-added compounds. This was achieved by orchestrating complex pathways involving up to 20 enzymes. Due to the novelty of the genetic approach, industrial applications are still rare. In addition, some applications are limited due to the lack of high-throughput screening methods. This shifts the bottleneck from library preparation to screening capacity and needs to be addressed by future developments to pave the path for the establishment of Modular Cloning in industrial applications
Fostering a Coordinated Teaching of the Experimental Sciences: Introduce Entropy and Chemical Potential from the Beginning! Balmer Prize 2022
No full textUsing a conceptual framework based a) on a model where energy is the regulating agent and b) on the introduction of conjugated intensive and extensive quantities, together with the introduction from the beginning of the concepts of entropy and chemical potential allows to coherently model a variety of situations relating to didactically interesting examples referring to different disciplines
Molecular Bio-inspired Strategies for the Design of Electrocatalytic Systems: Werner Prize 2023
No full textThis perspective article delves into the realm of bio-inspired catalysis, highlighting the valuable insights gleaned from enzymatic systems for the design of advanced electrocatalysts. We focus here on three key aspects to mimic: the structure of enzymatic active sites, the essential functions to enable catalytic activity as well as key elementary steps of reaction mechanisms employed by enzymes to ensure maximum efficiency and selectivity. Our research group\u27s contributions to these areas are highlighted, including the synthesis and catalytic activity of cobalt(III) pyridinethiolate complexes, the exploration of bimetallic sites mimicking biological carbon dioxide reductases and of all-ferrous Fe4S4 clusters as mimics of FeP active sites, and the integration of concerted proton-electron transfer (CPET) mediators for the generation of metal hydride species. We emphasize the potential of these bio-inspired approaches in advancing electrocatalyst design and their relevance to molecular catalysis