Unveiling N-Fused Nitreniums as Potent Catalytic Photooxidants

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(6), P. 3603 - 3608

Published: Jan. 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.

Language: 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, Journal Year: 2023, Volume and Issue: 145(22), P. 12214 - 12223

Published: May 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.

Language: Английский

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

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(5), P. 1160 - 1165

Published: Jan. 1, 2023

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

Language: Английский

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

Organic Letters, Journal Year: 2023, Volume and Issue: 25(33), P. 6189 - 6194

Published: Aug. 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.

Language: Английский

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

Organic Letters, Journal Year: 2022, Volume and Issue: 24(33), P. 6105 - 6110

Published: Aug. 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 %).

Language: Английский

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

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(5), P. 932 - 939

Published: Jan. 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.

Language: 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, Journal Year: 2022, Volume and Issue: 144(51), P. 23642 - 23648

Published: Dec. 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.

Language: 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, Journal Year: 2024, Volume and Issue: 11(7), P. 2070 - 2074

Published: Jan. 1, 2024

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

Language: Английский

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Photoinduced N‑Heterocyclic Nitrenium-Catalyzed Single Electron Reduction of α-Chloro Esters for Phenanthridine Synthesis

Organic & Biomolecular Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

An efficient photoactive charge transfer complex protocol for the synthesis of phenanthridine derivatives by reaction 2-isocyanobiaryls with α-chloro esters is established.

Language: Английский

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

Green Synthesis and Catalysis, Journal Year: 2024, Volume and Issue: unknown

Published: March 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.

Language: Английский

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