meta-Selective Radical Acylation of Electron-rich Arenes DOI Creative Commons
Yamato Goto,

Masaki Sano,

Yuto Sumida

et al.

Published: April 27, 2023

meta-Selective functionalisation of electron-rich arenes provides a non-traditional route to organic synthesis. In classical electrophilic aromatic substitution electron-donating group-pendant arenes, occurs according ortho- and para-orientation. There have been numerous efforts overcome this selectivity, various synthetic methods developed, mainly based on transition metal catalysis. Here, we show new N-heterocyclic carbene photoredox cocatalysis for meta-selective acylation arenes. This approach proceeds without the directing groups or steric factors required in catalysis, resulting precisely opposite regioselectivity from conventional approaches such as Friedel–Crafts acylation. The catalytic system involves sequence single electron oxidation an arene followed by radical–radical coupling between ketyl radical cation. protocol will lead expeditious synthesis molecules that commonly require multiple steps rare metals promotes construction libraries biologically active molecules.

Language: Английский

Photoinduced Dearomative Multiple Functionalization of Quinolines to Construct Highly Substituted 3D Frameworks DOI
Yuki Nagashima,

Asuha Shimose

Synlett, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 18, 2025

Abstract Dearomative functionalization of quinolines expands the chemical diversity highly functionalized 3D frameworks, such as 1,2,3,4- and 5,6,7,8-tetrahydroquinoline derivatives, which are important pharmacophores, with minimal synthetic costs. In this short review, we cover recent reports on visible-light-induced dearomative an emphasis reaction design/strategies mechanistic studies provide a theoretical basis for developing further syntheses in future. 1 Introduction 2 Functionalizations through Formation Photoexcited Quinolines 3 Reagents/Intermediates 4 Conclusion

Language: Английский

Citations

0
Reimagining Dearomatization: Arenophile-Mediated Single-Atom Insertions and π-Extensions DOI

Zohaib Siddiqi,

David Šarlah

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: March 11, 2025

ConspectusDearomatization of simple aromatics serves as one the most direct strategies for converting abundant chemical feedstocks into three-dimensional value-added products. Among such transformations, cycloadditions between arenes and alkenes have historically offered effective means to construct complex polycyclic architectures. However, traditionally harsh conditions, high-energy UV light irradiation, greatly limited scope this transformation. Nevertheless, recent progress has led development visible-light-promoted dearomative photocycloadditions with expanded capable preparing bicyclic structures.A fundamentally distinct approach involves visible-light activation arenophiles, which undergo para-photocycloaddition various aromatic compounds produce arene-arenophile cycloadducts. While only transiently stable subject retro-cycloaddition, further functionalization photocycloadducts allowed a wide collection dearomatization methodologies that access products orthogonal existing biological processes. Central strategy was observation photocycloaddition reveals π-system can be functionalized through traditional olefin chemistry. Coupled subsequent [4 + 2]-cycloreversion arenophile, process acts effectively isolate single from an ring. We developed several transformations bias methodology perform single-atom insertion π-extension reactions prepare unique cannot prepared easily means.Through application epoxidation, we were able develop method epoxidation pyridines arene-oxides pyridine-oxides, respectively. Notably, when arenophile chemistry is applied arenes, transposed site native olefinic reactivity, enabling site-selectivity functionalization. As result, oxygen (aza)arenes 3-benzoxepines. When applying in context cyclopropanations, accomplish cyclopropanation yield benzocycloheptatrienes upon cycloreversion. while Buchner ring expansion powerful carbon corresponding does not ring-expanded Furthermore, could utilized synthesis novel nanographenes M-region annulative (M-APEX) reaction. Traditionally, methods rely on reactivity at K- bay-region. arenophiles activate reactivity. arenophile-mediated diarylation, followed by cycloreversion, deliver π-extended exclusive selectivity.

Language: Английский

Citations

0
Tandem Azolation/Aromatization of Tetrahydronaphthalenes with Hydrogen Evolution via Organophotoredox/Cobalt Dual Catalysis DOI
Cheng Huang, Sheng Tang,

Chen-Lu Wang

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 27, 2025

Reported herein is a photoredox/cobaloxime dual-catalytic approach to execute tandem dehydrogenative azolation and aromatization of tetrahydronaphthalene for rapid construction N-(β-naphthyl)azole architectures. This protocol highlights noble metal-free external oxidants-free conditions, step- atom-economy, site-selectivity. A preliminary mechanistic study has uncovered that the transformation undergoes N-centered radical mediated C–H/N–H cross-coupling followed by saturated naphthyl surrogates under visible light irradiation, DFT calculations elucidate

Language: Английский

Citations

0
Electrochemical Mn-catalyzed nitrogenation of alkynes to nitriles via C C bonds cleavage DOI

Yuwei Liang,

Jianwei Huang, Zhiqiang Zhang

et al.

Chinese Chemical Letters, Journal Year: 2025, Volume and Issue: unknown, P. 111166 - 111166

Published: April 1, 2025

Language: Английский

Citations

0
Synthesis of Pyrroloindolines via N-Heterocyclic Carbene Catalyzed Dearomative Amidoacylation of Indole Derivatives DOI

Hanyu Shu,

Jia‐Nan Mo,

Wen-Deng Liu

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(48), P. 8677 - 8682

Published: Nov. 23, 2023

Pyrroloindoline is a privileged heterocyclic motif that widely present in many natural products and pharmaceutical compounds. Herein, we report an amidyl radical-mediated dearomatization for synthesizing series of pyrroloindolines via N-heterocyclic carbene catalysis. In this organocatalytic process, the Breslow enolate served as both single electron donor acyl radical equivalent to assemble C3a-acyl with broad substrate scope. Sequential reduction indole derivatives provided analogues (±)-desoxyeseroline, which exhibited potential anticancer activity.

Language: Английский

Citations

9
Construction of Bridged Benzazepines via Photo‐Induced Dearomatization DOI
Tingting Song, Yong‐Kang Mei, Yan Liu

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(2)

Published: Nov. 27, 2023

Abstract Bridged benzazepine scaffolds, possessing unique structural and physicochemical activities, are widespread in various natural products drugs. The construction of these skeletons often requires elaborate synthetic effort with low efficiency. Herein, we develop a simple divergent approach for constructing bridged benzazepines by photocatalytic intermolecular dearomatization naphthalene derivatives readily available α ‐amino acids. motif is created via cascade sequence involving 1,4‐hydroaminoalkylation, alkene isomerization cyclization. Interestingly, the diastereoselectivity can be regulated through different reaction modes cyclization step. Moreover, aminohydroxylation its further bromination have also been demonstrated to access highly functionalized benzazepines. Preliminary mechanistic studies performed get insights into mechanism. This method provides benzazepines, which otherwise difficult access.

Language: Английский

Citations

9
Mild and green thioacylation with dithiocarboxylates via photoredox catalysis DOI Creative Commons
Wen‐Chao Gao, Wei Li, Juan Zhang

et al.

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

Published: March 1, 2024

Language: Английский

Citations

3
Combining photoredox catalysis and hydrogen atom transfer for dearomative functionalization of electron rich heteroarenes DOI Creative Commons
Peng Ji, Meng Xiang, Jing Chen

et al.

Chemical Science, Journal Year: 2023, Volume and Issue: 14(12), P. 3332 - 3337

Published: Jan. 1, 2023

Engineering organophotoredox catalysis with hydrogen atom transfer directs toward an unfavorable dearomatization process under mild reaction conditions.

Language: Английский

Citations

8
Sulfenylnitrene-Mediated Nitrogen-Atom Insertion into Pyrroles, Indoles, and Imidazoles DOI Creative Commons
Bidhan Ghosh,

Prakash Kafle,

Rishav Mukherjee

et al.

Published: Feb. 12, 2024

In this study, we harness the distinct reactivity of sulfenylnitrenes, which insert a single nitrogen atom to transform readily available pyrroles, indoles, and imidazoles into synthetically challenging pyrimidines, quinazolines, triazines, respectively. Our additive-free method for skeletal editing employs easily accessible, benchtop-stable sulfenylnitrene precursors as source atom. This chemical approach is compatible with free diverse functional groups, including oxidation-sensitive functionalities like phenol thioether. Additionally, facilitates selective incorporation various natural products, amino acids, pharmaceuticals. Furthermore, have conducted mechanistic studies explored regioselectivity outcomes through DFT calculations.

Language: Английский

Citations

2
Dearomative dimerization of quinolines and their skeletal rearrangement to indoles triggered by single-electron transfer DOI Creative Commons

Eugene Yew Kun Tan,

Alireza Dehdari,

Amirah S. Mat Lani

et al.

Published: May 29, 2024

Dearomatization of two-dimensional (2D) planar aromatic feedstocks enables the introduction three-dimensional (3D) vectors to new molecular scaffolds, vastly expanding chemical space for drug discovery. Here, we demonstrate that photoinduced single-electron reduction quinolines under polysulfide anion photocatalysis triggers dearomative dimerization and an unprecedented skeletal rearrangement. In presence excess formate as stoichiometric reductant, a complex polyheterocyclic hybrid 2,5-methanobenzo[b]azepine tetrahydroisoquinoline is formed in net-reductive manner, whereas trialkylamine instead formate, sequential rearrangement occurs afford 4-(3-indolylmethyl)quinolines redox-neutral manner. The remarkable way which additive dictates reaction course showcases unique tunability mediated redox photocatalysis. These observations enabled design 4-arylquinolines 3-(arylmethyl)indoles. Detailed mechanistic investigations reveal this umpolung transformation from electron-deficient electron-rich indoles via 1,2-aryl migration/ring-contraction sequence, opposed more commonly invoked neophyl-like

Language: Английский

Citations

1