A mechanistic and cautionary case study on the use of alternating potential in electrochemical reactions

A mechanistic study on use of alternating potential (i. e. electrode polarity switching) in synthetic organic electrochemical method development using the IKA ElectraSyn 2.0 is described. Unexpected product selectivity challenges revealed that alternating potential facilitated direct, rather than mediated, electrochemical benzylic C−H oxidation of toluene derivatives. Whilst constant potential irrespective of the direction of electrode polarity was expected, our in-depth analysis revealed changes in the magnitude of applied potential with periodic switching of electrode polarity. These findings highlight an equipment engineering concern that is likely to influence and inform optimization strategies for a wide range of synthetic organic electrochemical methods under development

The Theoretical Astrophysical Observatory: Cloud-Based Mock Galaxy Catalogues

We introduce the Theoretical Astrophysical Observatory (TAO), an online virtual laboratory that houses mock observations of galaxy survey data. Such mocks have become an integral part of the modern analysis pipeline. However, building them requires an expert knowledge of galaxy modelling and simulation techniques, significant investment in software development, and access to high performance computing. These requirements make it difficult for a small research team or individual to quickly build a mock catalogue suited to their needs. To address this TAO offers access to multiple cosmological simulations and semi-analytic galaxy formation models from an intuitive and clean web interface. Results can be funnelled through science modules and sent to a dedicated supercomputer for further processing and manipulation. These modules include the ability to (1) construct custom observer light-cones from the simulation data cubes; (2) generate the stellar emission from star formation histories, apply dust extinction, and compute absolute and/or apparent magnitudes; and (3) produce mock images of the sky. All of TAO's features can be accessed without any programming requirements. The modular nature of TAO opens it up for further expansion in the future.Comment: 17 pages, 11 figures, 2 tables; accepted for publication in ApJS. The Theoretical Astrophysical Observatory (TAO) is now open to the public at https://tao.asvo.org.au/. New simulations, models and tools will be added as they become available. Contact [email protected] if you have data you would like to make public through TAO. Feedback and suggestions are very welcom

Synthesis of Tetrahydroxyazepanes from Shikimic Acid

The 13th International Electronic Conference on Synthetic Organic Chemistry session General Organic SynthesisWe describe herein a novel synthetical application of shikimic acid, which consist of its transformation into (3R,4S,5R,7S)-7-(hydroxymethyl)azepane-3,4,5-triolWe thank the Spanish Ministry Science and Innovation and the Xunta de Galicia for financial suppor

Semi-Analytic Galaxy Evolution (SAGE): Model Calibration and Basic Results

This paper describes a new publicly available codebase for modelling galaxy formation in a cosmological context, the "Semi-Analytic Galaxy Evolution" model, or SAGE for short. SAGE is a significant update to that used in Croton et al. (2006) and has been rebuilt to be modular and customisable. The model will run on any N-body simulation whose trees are organised in a supported format and contain a minimum set of basic halo properties. In this work we present the baryonic prescriptions implemented in SAGE to describe the formation and evolution of galaxies, and their calibration for three N-body simulations: Millennium, Bolshoi, and GiggleZ. Updated physics include: gas accretion, ejection due to feedback, and reincorporation via the galactic fountain; a new gas cooling--radio mode active galactic nucleus (AGN) heating cycle; AGN feedback in the quasar mode; a new treatment of gas in satellite galaxies; and galaxy mergers, disruption, and the build-up of intra-cluster stars. Throughout, we show the results of a common default parameterization on each simulation, with a focus on the local galaxy population.Comment: 15 pages, 9 figures, accepted for publication in ApJS. SAGE is a publicly available codebase for modelling galaxy formation in a cosmological context, available at https://github.com/darrencroton/sage Questions and comments can be sent to Darren Croton: [email protected]

Et3SiH + KOtBu provide multiple reactive intermediates that compete in the reactions and rearrangements of benzylnitriles and indolenines

The combination of potassium tert-butoxide and triethylsilane is unusual because it generates multiple different types of reactive intermediates simultaneously that provide access to (i) silyl radical reactions, (ii) hydrogen atom transfer reactions to closed shell molecules and to radicals, (iii) electron transfer reductions and (iv) hydride ion chemistry, giving scope for unprecedented outcomes. Until now, reactions with this reagent pair have generally been explained by reference to one of the intermediates, but we now highlight the interplay and competition between them

Bridge functionalisation of bicyclo[1.1.1]pentane derivatives

"Escaping from flatland", by increasing the saturation level and three-dimensionality of drug-like compounds, can enhance their potency, selectivity and pharmacokinetic profile. One approach that has attracted considerable recent attention is the bioisosteric replacement of aromatic rings, internal alkynes and tert-butyl groups with bicyclo[1.1.1]pentane (BCP) units. While functionalisation of the tertiary bridgehead positions of BCP derivatives is well-documented, functionalisation of the three concyclic secondary bridge positions remains an emerging field. The unique properties of the BCP core present considerable synthetic challenges to the development of such transformations. However, the bridge positions provide novel vectors for drug discovery and applications in materials science, providing entry to novel chemical and intellectual property space. This minireview aims to consolidate the major advances in the field, serving as a useful reference to guide further work that is expected in the coming years