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Nitrate esters hold pivotal roles in pharmaceuticals, energetic materials, and atmospheric processes, motivating the development of efficient synthesis routes. Here, we present a novel catalytic method for the synthesis of nitrates via the direct O-nitration of alcohols, addressing limitations of current traditional methods. Leveraging bench-stable and recoverable N,6-dinitrosaccharin reagent, our catalytic strategy employs magnesium triflate to achieve mild and selective O-nitration of alcohols, offering broad substrate scope and unprecedentedly large functional group tolerance (e.g. alkenes, alkynes, carbonyls). DFT mechanistic studies reveal a dual role of the magnesium catalyst in the activation of both the nitrating reagent and the alcohol substrate. They also unveil a barrierless proton transfer upon formation of a widely-accepted - yet elusive in solution - nitrooxonium ion intermediate. Overall, our work contributes to the development of mild, selective, and sustainable approaches to nitrates synthesis, with potential applications in drug discovery, materials science, and environmental chemistry., (© 2024 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

We highlight key contributions in the field of direct radical C Ar - H (hetero)aromatic functionalization involving fluorinated radicals. A compilation of Functional Group Transfer Reagents and their diverse activation mechanisms leading to the release of radicals are discussed. The substrate scope for each radical is analyzed and classified into three categories according to the electronic properties of the substrates. Density functional theory computational analysis provides insights into the chemical reactivity of several fluorinated radicals through their electrophilicity and nucleophilicity parameters. Theoretical analysis of their reduction potentials also highlights the remarkable correlation between electrophilicity and oxidizing ability. It is also established that highly fluorinated radicals (e.g. ⋅OCF 3 ) are capable of engaging in single-electron transfer (SET) processes rather than radical addition, which is in good agreement with experimental literature data. A reactivity scale, based on activation barrier of addition of these radicals to benzene is also elaborated using the high accuracy DLPNO-(U)CCSD(T) method., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Nitroaromatic compounds represent one of the essential classes of molecules that are widely used as feedstock for the synthesis of intermediates, the preparation of nitro-derived pharmaceuticals, agrochemicals, and materials on both laboratory and industrial scales. We herein disclose the efficient, mild, and catalytic ipso-nitration of organotrimethylsilanes, enabled by an electrophilic N-nitrosaccharin reagent and allows chemoselective nitration under mild reaction conditions, while exhibiting remarkable substrate generality and functional group compatibility. Additionally, the reaction conditions proved to be orthogonal to other common functionalities, allowing programming of molecular complexity via successive transformations or late-stage nitration. Detailed mechanistic investigation by experimental and computational approaches strongly supported a classical electrophilic aromatic substitution (S E Ar) mechanism, which was found to proceed through a highly ordered transition state., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

p-Toluenesulfonyl (Tosyl) and nitrobenzenesulfonyl (Nosyl) are two of the most common sulfonyl protecting groups for amines in contemporary organic synthesis. While p-toluenesulfonamides are known for their high stability/robustness, their use in multistep synthesis is plagued by difficult removal. Nitrobenzenesulfonamides, on the other hand, are easily cleaved but display limited stability to various reaction conditions. In an effort to resolve this predicament, we herein present a new sulfonamide protecting group, which we term Nms. Initially developed through in silico studies, Nms-amides overcome these previous limitations and leave no room for compromise. We have investigated the incorporation, robustness and cleavability of this group and found it to be superior to traditional sulfonamide protecting groups in a broad range of case studies., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

We report herein a straightforward transfer of a free amino group (NH 2 ) from a commercially available nitrogen source to unfunctionalized, native carbonyls (amides and ketones) resulting in direct α-amination. Primary α-amino carbonyls are readily produced under mild conditions, further enabling diverse in situ functionalization reactions-including peptide coupling and Pictet-Spengler cyclization-that capitalize on the presence of the unprotected primary amine., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Herein we report a method for the synthesis of α-aryl acrylamides leveraging polar S-to-C aryl migrations induced by a Lewis basic organocatalyst. In contrast to previously reported radical aryl migrations of sulfonyl acrylimides, this polar process enables subsequent elimination, ultimately leading to a formal aryl/hydrogen exchange including SO 2 extrusion. This reaction is selective for electron-deficient aromatic groups, while tolerating a variety of substituents on nitrogen and in the β-position, and it delivers useful building blocks for further transformations, including cycloaddition and cyclisation reactions. The mechanism was investigated in detail using quantum chemical calculations, which unexpectedly revealed the Lewis base to be involved in several decisive steps., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The structure determination of a series of biphenylsilyloxonium cations through NMR and XRD studies, supported by DFT calculations was carried out, allowing to get insights into the origin of the oxygen pyramidalization in biphenyl and binaphthylsilyl oxoniums. Low barrier of inversion in the oxygenyl series points toward a key role of the biaryl axis in the inversion of configuration at the oxygen center., (© 2021 Wiley-VCH GmbH.)

A highly hydrophilic carbon nanomaterial was generated by using an electrochemical approach, and its structure, chemical composition, redox properties, antioxidant activity and effects on cells were characterised. It was found that the nanomaterial possesses a structure dominated by sp 2 carbon atoms in a non-ordered carbon network formed by small clusters (<2 nm) of a carbonaceous material. This material has an outstanding capability for donating electrons and an unusual ability to bind metal cations. Antioxidant activity assays showed that it displays a high scavenging activity against both 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals, and a concentration-dependent ability to protect mitochondrial lipids and intracellular thiol groups from oxidation promoted by external oxidising agents. Cell-based assays also revealed that the nanomaterial has the ability to protect neuronal cells against oxidative damage and toxicity promoted by tert-butyl hydroperoxide and amyloid-β 1-42 peptide. These results, combined with the attractive methodology for generating this hydrophilic carbon-based nanomaterial, make this study the first step in addressing the therapeutic application of this new material., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)