Unveiling N-Fused Nitreniums as Potent Catalytic Photooxidants

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(6), С. 3603 - 3608

Опубликована: Янв. 31, 2024

The first example of a hitherto-unknown facet catalytic photooxidant capability nitrenium cations is reported herein. fundamental limitation inability the traditional and nitreniums to achieve excited-state redox potential beyond +2.0 V (vs Ag/AgCl), primary requirement for powerful photooxidant, addressed in this work by developing structurally unique class N-fused cations, with required structural engineering involving extensive π-conjugation through ring fusion at site, which enabled significant lowering LUMO energy easy reduction excited state (excited-state up +2.5 vs facilitated effective delocalization/stabilization generated radical. This finding opens new way discover novel useful (photo)catalytic properties just Lewis acidity.

Язык: Английский

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Skeletal Transformation of Unactivated Arenes Enabled by a Low-Temperature Dearomative (3 + 2) Cycloaddition

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(22), С. 12214 - 12223

Опубликована: Май 24, 2023

Simple aromatic compounds like benzene are abundant feedstocks, for which the preparation of derivatives chiefly begins with electrophilic substitution reactions or, less frequently, reductions. Their high stability makes them particularly reluctant to participate in cycloadditions under ordinary reaction conditions. Here, we demonstrate exceptional ability 1,3-diaza-2-azoniaallene cations undergo formal (3 + 2) unactivated below room temperature, providing thermally stable dearomatized adducts on a multi-gram scale. The cycloaddition, tolerates polar functional groups, activates ring toward further elaboration. On treatment dienophiles, cycloadducts (4 cycloaddition–cycloreversion cascade yield substituted or fused arenes, including naphthalene derivatives. overall sequence results transmutation arenes through an exchange carbons: two-carbon fragment from original is replaced another incoming dienophile, introducing unconventional disconnection synthesis ubiquitous building blocks. Applications this two-step acenes, isotopically labeled molecules, and medicinally relevant demonstrated.

Язык: Английский

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Additive free, N-heterocyclic nitrenium catalyzed photoreduction of cycloketone oxime esters

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(5), С. 1160 - 1165

Опубликована: Янв. 1, 2023

N-Heterocyclic nitrenium iodide salts can be used as ideal charge transfer complex catalysts for the photoreduction of cycloketone oxime esters.

Язык: Английский

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N-Heterocyclic Nitrenium-Catalyzed Photohomolysis of CF₃SO₂Cl for Alkene Trifluoromethylation

Organic Letters, Год журнала: 2023, Номер 25(33), С. 6189 - 6194

Опубликована: Авг. 14, 2023

N-Heterocyclic nitreniums (NHNs) have been utilized as Lewis acid catalysts to activate substrates with lone pairs. Alternative their conventional applications, we discovered that NHNs can also serve charge transfer complex catalysts. Herein, present another potential of by utilizing a weak interaction between and CF3SO2Cl. The method promotes CF3SO2Cl undergo photohomolysis, resulting in the CF3 radical. Mechanistic studies suggested could be due π-hole effect NHNs.

Язык: Английский

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Benzotriazolium Salts: Emergent Readily Accessible Bench-Stable Lewis Acid Catalysts

Organic Letters, Год журнала: 2022, Номер 24(33), С. 6105 - 6110

Опубликована: Авг. 16, 2022

In this work, benzotriazolium salts have been introduced as efficient, readily accessible, bench-stable Lewis acid catalysts. Though these sorts of N-heterocyclic compounds found wide applications ionic liquids or electrolytes, their catalytic activity remained unexplored. Herein, potential catalysts was demonstrated in two prototypical allylic and Nazarov cyclization reactions, showing a matching reactivity allowing low loadings (down to 0.5 mol %).

Язык: Английский

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TiCl₄-mediated deoxygenative reduction of aromatic ketones to alkylarenes with ammonia borane

Organic & Biomolecular Chemistry, Год журнала: 2024, Номер 22(5), С. 932 - 939

Опубликована: Янв. 1, 2024

A rapid and mild protocol for the exhaustive deoxygenation of various aromatic ketones to corresponding alkanes using AB as a reductant TiCl 4 catalyst.

Язык: Английский

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Multimodal Reactivity of N–H Bonds in Triazanes and Isolation of a Triazinyl Radical

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(51), С. 23642 - 23648

Опубликована: Дек. 16, 2022

The employment of nitrogen Lewis acids based on nitrenium cations has been increasingly featured in the fields main group chemistry and catalysis. A formally reduced form D─cyclic triazanes E─are intriguing chemical compounds, which is completely unexplored. In this work, we reveal that N–H-triazanes exhibit unusual N–H bond properties; namely, they can serve as protons, hydrides, or hydrogen atom donors. This unique multimodal reactivity provides an N-cation, N-anion, N-radical from same species. It allowed us to isolate, for first time, a stable naphto[1,2,3]triazinyl radical, was fully characterized both computationally experimentally, including its monomeric X-ray structure. Moreover, radical be prepared directly cation by single electron reduction (E = −0.46 V), process reversible. We envision versatile uses synthetic materials chemistry.

Язык: Английский

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Photoinduced N-heterocyclic nitrenium-catalyzed single electron reduction of Se–Se bond for the generation of nucleophilic selenolates

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(7), С. 2070 - 2074

Опубликована: Янв. 1, 2024

A straightforward photoinduced NHN-catalyzed method for generating nucleophilic selenolates from diselenides without the need of stoichiometric reductants.

Язык: Английский

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N-Heterocyclic nitrenium-catalyzed photoreductive radical-polar crossover for alkene dicarbofunctionalization

Green Synthesis and Catalysis, Год журнала: 2024, Номер unknown

Опубликована: Март 1, 2024

The photoredox radical-polar crossover paradigm is a valuable tool for 1,2-difunctionalization of alkenes. However, the use unactivated alkyl halides as radical precursors remains far less developed. Here, we report photoreductive N-heterocyclic nitrenium-catalyzed 1,2-dicarbofunctionalization alkenes by using and aryl iodides. These reactions can be carried out under simple, transition-metal-free conditions with easily obtainable materials such alkyl/aryl halides, alkenes, aldehydes. exhibit broad range substrate compatibility good tolerance towards functional groups. This approach offers new to unlock carbon skeletons.

Язык: Английский

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Development of Modular Nitrenium Bipolar Electrolytes for Possible Applications in Symmetric Redox Flow Batteries

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(28), С. 19474 - 19488

Опубликована: Июль 4, 2024

Amid the escalating integration of renewable energy sources, demand for grid storage solutions, including non-aqueous organic redox flow batteries (oRFBs), has become ever more pronounced. oRFBs face a primary challenge irreversible capacity loss attributed to crossover redox-active materials between half-cells. A possible solution involves utilization bipolar electrolytes that act as both catholyte and anolyte. Identifying such molecules poses several challenges it requires delicate balance stability oxidation states density, which is influenced by separation two events. We report development diaminotriazolium core capable producing electronically distinct persistent radical species with typically extreme reduction potentials (

Язык: Английский

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