Revisiting aromatic diazotization and aryl diazonium salts in continuous flow: highlighted research during 2001–2021

Reaction Chemistry & Engineering, Год журнала: 2022, Номер 7(6), С. 1247 - 1275

Опубликована: Янв. 1, 2022

Aryl diazonium salts play an important role in chemical transformations; however their explosive nature limits applications batch.

Язык: Английский

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Recent Advances in Photoredox-Catalyzed Difunctionalization of Alkenes

Catalysts, Год журнала: 2023, Номер 13(7), С. 1056 - 1056

Опубликована: Июнь 30, 2023

Alkenes and their related analogs are ideal starting materials for organic synthesis, the selective difunctionalization of alkenes, which allows simultaneous introduction two neighboring bonds, has gained considerable attention in recent years. In particular, photoredox-catalyzed alkenes also been accomplished, regarded as an increasingly powerful tool synthesis miscellaneous interesting molecular scaffolds environmentally benign economical manner. Several exquisite strategies have developed to facilitate this transformation, such photosensitizer-catalyzed redox reactions, electron donor-acceptor (EDA) complexes-mediated photoreactions, atom transfer radical addition (ATRA) reactions. This literature review briefly describes most key progress on 1,2-difunctionalization various structurally diverse including 1,2-dicarbofunctionalization, 1,2-carboheterofunctionalization, 1,2-diheterofunctionalization, with a special emphasis mechanistic details.

Язык: Английский

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Modern photo- and electrochemical approaches to aryl radical generation

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(18), С. 5232 - 5277

Опубликована: Янв. 1, 2024

This review describes recent advances in the generation of aryl radicals using light and electricity. Such modern techniques allow for efficient energy resource utilization, thus providing more sustainable radical arylation methods.

Язык: Английский

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Room-Temperature Copper-Mediated Radiocyanation of Aryldiazonium Salts and Aryl Iodides via Aryl Radical Intermediates

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(12), С. 6921 - 6926

Опубликована: Март 14, 2023

Radiocyanation is an attractive strategy for incorporating carbon-11 into radiotracer targets, particularly given the broad scope of acyl moieties accessible from nitriles. Most existing methods aromatic radiocyanation require elevated temperatures (Cu-mediated reactions aryl halides or organometallics) involve expensive and toxic palladium complexes (Pd-mediated halides). The current report discloses a complementary approach that leverages capture radical intermediates by Cu–11CN complex to achieve rapid mild (5 min, room temperature) radiocyanation. In first example, radicals are generated via reaction CuI mediator with aryldiazonium salt (a Sandmeyer-type reaction) followed Cu–11CN. second formed iodides visible-light photocatalysis then captured species aryl–11CN coupling. This provides access radiocyanated products challenging using other (e.g., ortho-disubstituted nitriles).

Язык: Английский

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One‐Carbon Ring Expansion of Indoles and Pyrroles: A Straightforward Access to 3‐Fluorinated Quinolines and Pyridines

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(5)

Опубликована: Дек. 12, 2023

Abstract 3‐Fluorinated quinolines and pyridines are prevalent pharmacophores, yet their synthesis is often challenging. Herein, we demonstrate that dibromofluoromethane as bromofluorocarbene source enables the one‐carbon ring expansion of readily available indoles pyrroles to structurally diverse 3‐fluorinated pyridines. This straightforward protocol requires only a short reaction time ten minutes can be performed under air atmosphere. Preliminary investigations reveal this strategy also applied other valuable azines by using different 1,1‐dibromoalkanes bromocarbene sources.

Язык: Английский

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Generation of aryl radicals fromin situactivated homolytic scission: driving radical reactions by ball milling

Green Chemistry, Год журнала: 2022, Номер 24(11), С. 4557 - 4565

Опубликована: Янв. 1, 2022

The need for an operationally straightforward application of radical chemistry has led researchers to explore practical strategies obtain and trap radicals.

Язык: Английский

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One-Pot Three-Component Reaction for the Synthesis of 3,4-Dihydroquinazolines and Quinazolin-4(3H)-ones

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(9), С. 6428 - 6443

Опубликована: Апрель 12, 2024

A highly efficient and straightforward one-pot synthesis of diversely substituted 3,4-dihydroquinazolines quinazolin-4(3H)-ones has been achieved through a domino three-component assembly reaction arenediazonium salts, nitriles, bifunctional aniline derivatives. This new protocol involves three C–N bond formations the initial formation N-arylnitrilium intermediates from salts followed by sequential nucleophilic addition cyclization reactions with anilines, leading to such N-heterocyclic compounds biological pharmacological importance. method offers simple, expedient, robust approach use amenable easily accessible reactants/reagents under metal-free mild conditions, good functional group tolerance, high efficiency. The synthetic applications were also demonstrated derivatization products obtained these processes syntheses diverse range valuable polycyclic N-heterocycles.

Язык: Английский

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Photo- and Cu-Mediated ¹¹C Cyanation of (Hetero)Aryl Thianthrenium Salts

Organic Letters, Год журнала: 2024, Номер 26(16), С. 3419 - 3423

Опубликована: Апрель 17, 2024

We present a photo- and Cu-mediated 11C cyanation of bench-stable (hetero)aryl thianthrenium salts via an aryl radical addition pathway. The substrates can be readily accessed C–H functionalization, the radiocyanation protocol proceeds under mild conditions (<50 °C, 5 min) automated using open-source, accessible augmentations to existing radiochemistry equipment.

Язык: Английский

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Generation of 1,2-Difluorobenzene via a Photochemical Fluorodediazoniation Step in a Continuous Flow Mode

Organic Process Research & Development, Год журнала: 2023, Номер 27(2), С. 322 - 330

Опубликована: Янв. 16, 2023

A proof-of-concept study for the synthesis of 1,2-difluorobenzene from 2-fluoroaniline via Balz–Schiemann reaction using HF/pyridine as fluorinating reagent is reported. Key to success a fast reaction, clean profile─and thus high product selectivity─was photochemically induced fluorodediazoniation in situ-generated diazonium salt performed continuous flow mode. high-power 365 nm light-emitting diode provided more robust and efficient irradiation system compared medium-pressure Hg lamp with respect performance on scale-out runs time, allowing generation within 10 min residence time selectivity ≥95% at full conversion.

Язык: Английский

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Synthesis of Functionalized Thioimidates from Thioamides and Arylboronic Acids via Copper-Catalyzed Cross-Coupling Reaction at Room Temperature

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

Опубликована: Фев. 19, 2025

Functionalized S-aryl thioimidates were synthesized from thioamides and arylboronic acids at room temperature under mild conditions. The reaction was catalyzed by copper(II) acetate in the presence of DBU an open atmosphere. A wide range functionalized aryl alkyl boronic chemo-selectively coupled with to obtain corresponding S-alkyl 64–80% yields. Room reactions, easy operation, broad substrate scope are salient features developed methodology.

Язык: Английский

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