Visible-Light-Promoted N-Alkylation Reactions of (aza)Aromatic Amines with Ethyl Diazoacetate DOI Open Access

Yating Zhao,

Fan Liu,

Qiuan Wang

et al.

Acta Chimica Sinica, Journal Year: 2023, Volume and Issue: 81(2), P. 111 - 111

Published: Jan. 1, 2023

Unnatural α-amino acid derivatives are greatly important in pharmaceuticals and biochemicals owing to their diverse biological activities, usually serve as versatile building blocks organic synthesis well.A variety of approaches have been developed prepare derivatives, among which N-H insertion reactions diazo compounds considered be one the most direct methods.These typically proceed through carbene active intermediates that derived from by UV-induction or metal catalysis.As a green powerful avenue synthesis, visible-light-mediated methodology has also applied principally intermediates.Due single reaction mechanism these reactions, however, scope were limited α-aryl diazoacetates can directly absorb visible-light.Therefore, exploring new activation modes is conducive expanding applicable type visiblelight-mediated reactions.Herein we report visible-light-promoted N-alkylation (aza)aromatic amines with ethyl diazoacetate based on proton-coupled electron transfer (PCET).A series synthesized combination photocatalyst Lewis-acid catalyst.This method featured mild conditions, good functional group tolerance wide range substrate scope.Mechanism experiments indicated involved radical intermediate rather than engaged conventional reactions.According fluorescence quenching experiment, alkyl was formed PCET step between excited photocatalyst.And then radicals cross-coupling occurred under coordination produce final products.This catalytic strategy expands applications visible-light chemical reactions.The general procedure for following: Aniline 1a (0.1 mmol), 2 (0.2 Fe(OTf)2 (0.02 mmol) [Ir(ppy)2(NCMe)2]PF6 (0.005 dissolved MeOH (2 mL).Then mixture degassed via "freeze-pump-thaw" (3 times).After that, resulting stirred irradiation 30 W blue LEDs at room temperature.Upon completion, crude product purified flash chromatograph silica gel give product.

Language: Английский

Photodriven Radical-Polar Crossover Cyclization Strategy: Synthesis of Pyrazolo[1,5-a]pyridines from Diazo Compounds DOI
Peng Zhao, Yanbo Liu, Yuting Zhang

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(12), P. 2511 - 2516

Published: March 20, 2024

This work demonstrates the synthesis of a variety perfluoroalkyl heterocycles via visible-light-driven radical-polar crossover cyclization strategy. In this process, single-electron reduction/SNV-type/cyclization sequences follow radical addition reaction diazoester, which differs from current role diazoesters as precursors/acceptors. transformation excellent functional group compatibility and allows for modification many bioactive molecules with diazoesters. Such could represent novel approach to photochemical diazo compounds.

Language: Английский

Citations

18
Photocatalytic Synthesis of Indanone, Pyrone, and Pyridinone Derivatives with Diazo Compounds as Radical Precursors DOI
Yang Xie,

Ye‐Peng Bao,

Xiao-Yan Zhuo

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(7), P. 1393 - 1398

Published: Feb. 12, 2024

We disclose herein a photocatalytic radical cascade cyclization of diazoalkanes for the divergent synthesis important carbocycles and heterocycles. Under optimal reaction conditions, various indanone, pyrone, pyridinone derivatives can be obtained in moderate to good yields. Mechanistic experiments support formation carbon-centered radicals from through proton-coupled electron transfer process. Scale-up using continuous flow technology useful downstream application formed heterocycles further render strategy attractive valuable.

Language: Английский

Citations

10
Photocatalytic Regioselective Difunctionalization of Alkenes with Diazo Compounds and tert-Butyl Nitrite: Access to γ-Oximino Esters DOI
Yantao Liu,

Keyong Zhu,

Jingjing Zhao

et al.

Organic Letters, Journal Year: 2022, Volume and Issue: 24(37), P. 6834 - 6838

Published: Sept. 8, 2022

A visible-light photocatalytic regioselective difunctionalization of alkenes with diazo compounds and tert-butyl nitrite has been developed. The protocol provides an efficient approach to γ-oximino esters under mild conditions. Significantly, this transformation not only shows the good compatibility nucleophilic electrophilic but also displays generating alkyl radicals that preferred addition over nitroso radicals.

Language: Английский

Citations

28
Rhodium(III)-Catalyzed Annulative Coupling between Sulfoxonium Ylides and Diazo Compounds DOI
Fan Yang, Xiaomeng Fan, Xuejing Yao

et al.

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(1), P. 331 - 331

Published: Jan. 1, 2025

Language: Английский

Citations

0
Recent Progress of Visible Light-Induced the Synthesis of C(3) (Hetero)arylthio Indole Compounds DOI Open Access

Qinggang Mei,

Qinghan Li

Chinese Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 44(2), P. 398 - 398

Published: Jan. 1, 2024

The structure of 3-sulfenyl indoles widely exists in many drug molecules and natural product molecules.Its derivatives have extensive biological activities such as antibacterial, antiviral anti-tumor, are also important intermediates organic synthesis structural units synthesis.Therefore, indole compounds great application value the field medicine.The research its method has become one current hotspots.In this paper, progress recent years is reviewed, some reaction mechanisms discussed.

Language: Английский

Citations

3
Ru-Catalyzed Hydrogen Atom Transfer/C–F Bond Cleavage of Difluoroalkyl Diazos with Hantzsch Ester via a Photocatalytic Radical Process DOI
Qian Wang, Jiang Liu, Haibo Mei

et al.

Organic Letters, Journal Year: 2022, Volume and Issue: 24(43), P. 8036 - 8040

Published: Oct. 26, 2022

A Ru-catalyzed reaction of difluoroalkyl diazo compounds with Hantzsch ester under visible light to achieve the formation α-fluorovinylphosphonates via a radical process has been developed. Mechanistic experiments and density functional theory calculations reveal that generation carbon is directly through hydrogen atom transfer (HAT) by ester. This system represents first example radicals from Hantzsch-ester-assisted HAT also demonstrates new radical-involved pathway for compounds.

Language: Английский

Citations

14
C−H Functionalization of Heterocycles with Triplet Carbenes by means of an Unexpected 1,2‐Alkyl Radical Migration** DOI Creative Commons
Claire Empel, Sripati Jana, Łukasz W. Ciszewski

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(29)

Published: March 6, 2023

The C-H functionalization of indole heterocycles constitutes a key strategy to leverage the synthesis endogenous signaling molecules such as tryptamine or tryptophol. Herein, we report on photocatalytic reaction ethyl diazoacetate with indole, which shows an unusual solvent dependency. While C2-functionalization occurs under protic conditions, use aprotic solvents leads complete reversal selectivity and exclusive C3-functionalization occurs. To rationalize for this unexpected reactivity switch, have conducted detailed theoretical experimental studies, suggest participation triplet carbene intermediate that undergoes initial C2-functionalization. A distinct cationic [1,2]-alkyl radical migration then formation C3-functionalized indole. We conclude application access oxidized tryptophol derivatives including gram-scale derivatization reactions.

Language: Английский

Citations

8
Photochemical Synthesis of 1,4‐Dicarbonyl Containing Quinoxalin‐2(1H)‐Ones through Consecutive Photoredox Catalysis DOI

Cong‐Lun Xu,

Ye‐Peng Bao,

Yang Xie

et al.

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(8), P. 1833 - 1839

Published: Feb. 8, 2024

Abstract Herein, we report a photochemical synthesis of 1,4‐dicarbonyl containing quinoxalin‐2(1 H )‐ones through consecutive photoredox catalysed reactions. A wide range C3‐modified were obtained in 53–91% yields by this approach. Mechanistic studies including radical trapping, EPR studies, D‐labelling investigations, and many other control experiments well explained the proposed mechanism.

Language: Английский

Citations

2
Visible light-induced carbene reactivity of acceptor diazoalkanes: deconstructive difunctionalizations of cyclic ethers with nucleophiles DOI

Keyong Zhu,

Xinlong Zhou,

Yikun Ren

et al.

Chemical Communications, Journal Year: 2022, Volume and Issue: 59(5), P. 631 - 634

Published: Dec. 6, 2022

A visible light-induced carbene reactivity of acceptor diazoalkanes has been developed for the synthesis difunctionalized ethers from cyclic and various N/O/S nucleophiles.

Language: Английский

Citations

10
Electron Donor–Acceptor Complex Enabled Radical Cyclization of α-Diazodifluoroethyl Sulfonium Salt with Unactivated Alkynes DOI
Mingyue He, Xiaodong Tang,

Hao-Yan Wu

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(50), P. 9041 - 9046

Published: Dec. 13, 2023

An α-diazodifluoroethane sulfonium reagent was developed in this study to undergo [3 + 2] radical cyclization with unactivated alkynes give the corresponding 3-difluoromethyl pyrazoles under blue light irradiation conditions. The key success of transformation lies formation an electron donor-acceptor (EDA) complex between electron-deficient α-diazo salt and electron-rich triaryl amine. This circumvents a major substrate scope limitation polar cycloaddition reactions existent diazodifluoroethane reagents.

Language: Английский

Citations

6