Cycloaddition reactions─epitomized by the Diels-Alder reaction─offer an arguably unmatched springboard for achieving chemical complexity, often with excellent selectivity, in a modular single step. We report the synthesis of aza-acenaphthenes in a single step by an unprecedented formal -(3 + 2) cycloaddition of simple quinolines with alkynes. A commercially available iridium complex exerts a dual role of photosensitizer and photoredox catalyst, fostering a cyclization/rearomatization cascade. The initial energy-transfer phase leads to the acenaphthene skeleton, while the ensuing redox shuttling step leads to aromatization. We applied this technology to 8-substituted quinolines and phenanthrolines, which smoothly reacted with both terminal and internal alkynes with excellent levels of regio- and diastereoselectivity. Density functional theory calculations revealed the intertwined EnT/SET nature of the process and offered guiding design principles for the synthesis of new aza-acenaphthenes.
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http://dx.doi.org/10.1021/jacs.2c05687 | DOI Listing |
Langmuir
January 2025
Centre for Energy (M473), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
The mechanisms of NO reduction by CO over nitrogen-doped graphene (N-graphene)-supported single-atom Ni catalysts in the presence of O, HO, CO, and SO have been studied via density functional theory (DFT) modeling. The catalyst is represented by a single Ni atom bonded to four N atoms on N-graphene. Several alternative reaction pathways, including adsorption of NO on the Ni site, direct reduction of NO by CO, decomposition of NO to NO followed by reduction of NO to N, formation of active oxygen radical O*, and reduction of O* by CO, were hypothesized and the energy barrier corresponding to each of the reaction steps was calculated using DFT.
View Article and Find Full Text PDFJ Nurs Res
January 2025
College of Nursing & Health Science, Flinders University, Adelaide, Australia.
Background: Despite an overall decline in serious adverse events in hospitalized patients, approximately one third of inpatient mortality continues to relate to adverse events impacting patients on general wards. The preparedness of nurses, midwives, and nursing assistants (collectively referred to as ward-based staff) to recognize patient deterioration is therefore seen as critical.
Purpose: The aim of this study was to explore ward-based staff perspectives regarding their preparedness to recognize patient deterioration.
Proc Natl Acad Sci U S A
January 2025
Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6.
Although chromatin remodelers are among the most important risk genes associated with neurodevelopmental disorders (NDDs), the roles of these complexes during brain development are in many cases unclear. Here, we focused on the recently discovered ChAHP chromatin remodeling complex. The zinc finger and homeodomain transcription factor ADNP is a core subunit of this complex, and de novo mutations lead to intellectual disability and autism spectrum disorder.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
Single-atom catalysts (SACs) have attracted widespread attention due to their potential to replace platinum-based catalysts in achieving efficient oxygen reduction reaction (ORR), yet the rational optimization of SACs remains challenging due to their elusive reaction mechanisms. Herein, by employing ab initio molecular dynamics simulations and a thermodynamic integration method, we have constructed the potential-dependent free energetics of ORR on a single iron atom catalyst dispersed on nitrogen-doped graphene (Fe-N/C) and further integrated these parameters into a microkinetic model. We demonstrate that the rate-determining step (RDS) of the ORR on SACs is potential-dependent rather than invariant within the operative potential range.
View Article and Find Full Text PDFBrief Bioinform
November 2024
Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA 19104, United States.
Single-cell technologies have enabled the high-dimensional characterization of cell populations at an unprecedented scale. The innate complexity and increasing volume of data pose significant computational and analytical challenges, especially in comparative studies delineating cellular architectures across various biological conditions (i.e.
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