Aromatic nitrogen scanning by ipso -selective nitrene internalization

Science, Год журнала: 2023, Номер 381(6665), С. 1474 - 1479

Опубликована: Сен. 28, 2023

Nitrogen scanning in aryl fragments is a valuable aspect of the drug discovery process, but current strategies require time-intensive, parallel, bottom-up synthesis each pyridyl isomer because lack direct carbon-to-nitrogen (C-to-N) replacement reactions. We report site-directable C-to-N reaction allowing unified access to various pyridine isomers through nitrene-internalization process. In two-step, one-pot procedure, azides are first photochemically converted 3

Язык: Английский

---

Recent Advances in Reactions Involving Carbon Dioxide Radical Anion

ACS Catalysis, Год журнала: 2023, Номер 13(24), С. 15991 - 16011

Опубликована: Ноя. 28, 2023

Carbon dioxide radical anion (CO2•–) is a highly reactive nucleophilic species that has recently emerged in organic chemistry as strong single electron donor (reductant) and reactant for the synthesis of carboxylic acids. In general, CO2•– can be generated by either direct reduction CO2 or HAT formate salts. Achievements reactions involving have been witnessed recent years. This Review summarizes advances highlighting some challenges identifying potential areas improvement, which may offer inspiration future studies.

Язык: Английский

---

Kinetic and thermodynamic control of C(sp ² )–H activation enables site-selective borylation

Science, Год журнала: 2023, Номер 382(6675), С. 1165 - 1170

Опубликована: Дек. 7, 2023

Catalysts that distinguish between electronically distinct carbon-hydrogen (C–H) bonds without relying on steric effects or directing groups are challenging to design. In this work, cobalt precatalysts supported by N -alkyl-imidazole–substituted pyridine dicarbene (ACNC) pincer ligands described enable undirected, remote borylation of fluoroaromatics and expansion scope include electron-rich arenes, pyridines, tri- difluoromethoxylated thereby addressing one the major limitations first-row transition metal C–H functionalization catalysts. Mechanistic studies established a kinetic preference for bond activation at meta -position despite cobalt-aryl complexes resulting from ortho being thermodynamically preferred. Switchable site selectivity in as function boron reagent was preliminarily demonstrated using single precatalyst.

Язык: Английский

---

Generation and Application of Aryl Radicals Under Photoinduced Conditions

Chemistry - A European Journal, Год журнала: 2024, Номер 30(31)

Опубликована: Март 28, 2024

Abstract Photoinduced aryl radical generation is a powerful strategy in organic synthesis that facilitates the formation of diverse carbon‐carbon and carbon‐heteroatom bonds. The synthetic applications photoinduced complex compounds, including natural products, physiologically significant molecules, functional materials, have received immense attention. An overview current developments production methods their uses given this article. A generalized idea how to choose reagents approach for radicals described, along with techniques associated mechanistic insights. Overall, article offers critical assessment results as well selection reaction parameters specific context cascades, cross‐coupling reactions, functionalization, selective C−H functionalization substrates.

Язык: Английский

---

Photocatalytic low-temperature defluorination of PFASs

Nature, Год журнала: 2024, Номер 635(8039), С. 610 - 617

Опубликована: Ноя. 20, 2024

Язык: Английский

---

Reductive Arylation of Nitroarenes with Chloroarenes: Reducing Conditions Enable New Reactivity from Palladium Catalysts

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(29), С. 16150 - 16159

Опубликована: Июль 12, 2023

Palladium-catalyzed C-N bond forming reactions are a key tool in modern synthetic organic chemistry. Despite advances catalyst design enabling the use of variety aryl (pseudo)halides, necessary aniline coupling partner is often synthesized discrete reduction step from nitroarene. An ideal sequence would avoid necessity this while maintaining reliable reactivity palladium catalysis. Herein, we describe how reducing conditions enable new chemical steps and well-studied catalysts, resulting new, useful transformation: reductive arylation nitroarenes with chloroarenes to form diarylamines. Mechanistic experiments suggest that under conditions, BrettPhos-palladium complexes catalyze dual

Язык: Английский

---

Endo/Exo-Controllable Photocyclization by EnT-SET-Switch

Organic Letters, Год журнала: 2023, Номер 25(16), С. 2863 - 2867

Опубликована: Апрель 17, 2023

CBZ6, a redox-neutral non-donor-acceptor-type organo-photocatalyst, presents strong reductive potential with an oxidative of -2.16 V (vs SCE). It can work as photosensitizer for both single-electron transfer and triplet energy processes. This feature enables site-selective control in the intramolecular hydroarylation acrylamides. Both 5-exo-trig 6-endo-trig cyclization products could be prepared regiospecfically under mild conditions. No transition metal, halogen-containing reagents, or additional reductant oxidant is involved. process provides concise environmentally sustainable access to series oxindoles dihydroquinolinones.

Язык: Английский

---

Photocatalytic defluorocarboxylation using formate salts as both a reductant and a carbon dioxide source

Green Chemistry, Год журнала: 2023, Номер 25(16), С. 6194 - 6199

Опубликована: Янв. 1, 2023

Herein, we report a photocatalytic defluorocarboxylation of benzylic C(sp 3 )–F bonds using formate salts as both reductant and carbon dioxide source.

Язык: Английский

---

Visible Light-Induced Divergent Deoxygenation/Hydroxymethylation of Pyridine N-Oxides

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 9, 2025

This study explores the deoxygenation of pyridine N-oxides and presents a one-step photoredox method for direct synthesis 2-hydroxymethylated pyridines from N-oxides. Mechanism studies elucidate role catalyst provide evidence possible electron transfer process formation key radicals. A range derivatives, particularly 2-hydroxymethyl-substituted pyridines, which may be difficult to obtain, can synthesized in single step.

Язык: Английский

---

Reduction by Oxidation: Selective Hydrodehalogenation of Aryl Halides by Mediated Oxalate Oxidation

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Март 31, 2025

Electro-organic reduction reactions are canonically carried out at a cathode which significant negative potential is applied. Specifically, carbon electrodes, aryl bromides and chlorides undergo heterogeneous in organic solvents potentials more than −2 V vs E0′ for the Fc/Fc+ couple (Fc = ferrocene). To decrease overpotential reactions, homogeneous or electrocatalysis strategies often employed. Here, we present an electrochemical method to reduce that initiated by oxidation reaction very mild (∼0 Fc/Fc+). of outer-sphere redox mediator, 1,1-dimethylferrocene, dry N,N-dimethylformamide (DMF) containing oxalate (C2O42–), results one-electron C2O42–. The resulting C2O4•– decomposes ∼1 μs release dioxide radical anion (CO2•–), potent reductant oxidized CO2 –2.68 Fc/Fc+. In this way, low electrode enables chlorides, otherwise directly reduced potentials. Using method, selective hydrodehalogenations electron-deficient reticulated vitreous anode with up quantitative conversion yields. Cyclic voltammetry finite difference simulations used characterize hydrodehalogenation 4-bromobenzonitrile via C2O42– oxidation. Additionally, show efficiency tuned deliberate additions water DMF solutions, leading substantial improvement overall yields without interference from proton reduction.

Язык: Английский

---