Rhodium-Catalyzed Directed C(sp2)–H Bond Addition of 2-Arylindazoles to N-Sulfonylformaldimines and Activated Aldehydes DOI
Asim Kumar Ghosh, Payel Ghosh, Alakananda Hajra

и другие.

The Journal of Organic Chemistry, Год журнала: 2020, Номер 85(23), С. 15752 - 15759

Опубликована: Ноя. 13, 2020

Rhodium-catalyzed directed C-H functionalization of 2-arylindazoles with N-sulfonylformaldimines has been developed to provide a variety N-benzylarylsulfonamide derivatives good excellent yields. Different activated aldehydes like ethyl glyoxalate and 2,2,2-trifluoroacetaldehyde also efficiently underwent nucleophilic addition 2-arylindazoles. These selective transformations occur through the control C3 nucleophilicity indazole moiety. Mechanistic studies suggest that activation step may be rate-limiting step.

Язык: Английский

Electrochemical Functionalization of Imidazopyridine and Indazole: An Overview DOI
Debashis Ghosh, Sumit Ghosh, Alakananda Hajra

и другие.

Advanced Synthesis & Catalysis, Год журнала: 2021, Номер 363(22), С. 5047 - 5071

Опубликована: Окт. 1, 2021

Abstract Electrochemical synthesis offers a mild, simple, and efficient tool for the preparation of interesting useful molecules, thus eluding severe chemical oxidizing reducing agents used in conventional synthetic methods. In particular, electrochemical C−H activation is expected to play an important role direct functionalization heterocyclic compounds. Over past few decades, research interest imidazopyridine indazole has increased significantly due their multipurpose uses medicinal industrial chemistry. Therefore, structural modification these heterocycles using electro‐oxidation become one topics among organic chemistry recent time. This review provides comprehensive discussion indazoles imidazopyridines published so far. A summary current challenges future direction development green methods also presented. magnified image

Язык: Английский

Процитировано

90

Visible light-induced functionalization of indazole and pyrazole: a recent update DOI
Debashis Ghosh, Sumit Ghosh,

Anogh Ghosh

и другие.

Chemical Communications, Год журнала: 2022, Номер 58(28), С. 4435 - 4455

Опубликована: Янв. 1, 2022

Indazole and pyrazole are renowned as a prodigious class of heterocycles having versatile uses in medicinal well industrial chemistry. Considering sustainable approaches, recently, photocatalysis has become an indispensable tool organic chemistry due to its application for the activation small molecules use clean energy source. In this review, we have highlighted metal-based photocatalysts, photoredox catalysts, transfer photocatalysts electron-donor-acceptor complexes functionalization indazole pyrazole. This perspective is arranged based on types reactions A detailed discussion regarding reaction mechanism each given provide comprehensive guide reader. Finally, summary existing challenges future outlook towards development efficient photocatalytic methods these also presented.

Язык: Английский

Процитировано

58

Visible-light-induced metal-free coupling of C(sp3)–H sources with heteroarenes DOI

Anogh Ghosh,

Pranjal Pyne, Sumit Ghosh

и другие.

Green Chemistry, Год журнала: 2022, Номер 24(8), С. 3056 - 3080

Опубликована: Янв. 1, 2022

This critical review chronologically summarizes the metal-free coupling methodologies of C(sp 3 )–H sources with heteroarenes induced by visible light. The articles which are published up to January 2022 on this topic enclosed here.

Язык: Английский

Процитировано

47

Visible-light-induced direct 3-ethoxycarbonylmethylation of 2-aryl-2H-indazoles in water DOI
Chunhua Ma, Lu Zhao, Xing He

и другие.

Organic Chemistry Frontiers, Год журнала: 2022, Номер 9(5), С. 1445 - 1450

Опубликована: Янв. 1, 2022

A visible-light-driven rhodamine B-catalyzed transition-metal-free 3-ethoxycarbonylmethylation of 2-aryl-2 H -indazoles and imidazo[1,2- a ]pyridines (40 examples) using commercially available α-bromoesters was realized in water.

Язык: Английский

Процитировано

44

Visible-light-induced cascade reaction: a sustainable approach towards molecular complexity DOI
Sumit Ghosh, Pranjal Pyne,

Anogh Ghosh

и другие.

Organic & Biomolecular Chemistry, Год журнала: 2023, Номер 21(8), С. 1591 - 1628

Опубликована: Янв. 1, 2023

Photoredox catalysis has demonstrated rapid evolution in the field of synthetic organic chemistry. On other hand, splendour cascade reactions providing complex molecular architectures renders them a cutting-edge research area. Therefore, merging photocatalysis with synthesis brings out paradigm immense potential. The development photocascade for target molecule particular skeleton and stereochemical framework presents certain challenges but provides robust environmentally benign alternative. This comprehensive review assembles all accomplishments highlights visible-light-induced literature coverage up to October 2022.

Язык: Английский

Процитировано

30

Redox-neutral carbon–heteroatom bond formation under photoredox catalysis DOI
Sumit Ghosh, Souvik Majumder, Debashis Ghosh

и другие.

Chemical Communications, Год журнала: 2023, Номер 59(46), С. 7004 - 7027

Опубликована: Янв. 1, 2023

This feature article presents all the recent reports on photoredox-catalyzed redox-neutral carbon–heteroatom coupling reactions up to March 2023.

Язык: Английский

Процитировано

29

Condition-Controlled Selective Synthesis of Pyranone-Tethered Indazoles or Carbazoles through the Cascade Reactions of N-Nitrosoanilines with Iodonium Ylides DOI
Kelin Wang,

Xia Song,

Yongdi Xin

и другие.

Organic Letters, Год журнала: 2023, Номер 25(24), С. 4422 - 4428

Опубликована: Июнь 8, 2023

Presented herein is a condition-controlled selective synthesis of pyranone-tethered indazoles or carbazole derivatives via the cascade reactions N-nitrosoanilines with iodonium ylides. Mechanistically, formation former involves an unprecedented process including nitroso group-directed C(sp2)–H bond alkylation N-nitrosoaniline ylide followed by intramolecular C-nucleophilic addition to moiety, solvent-assisted cyclohexanedione ring opening, and transesterification/annulation. On contrary, latter initial annulation denitrosation. These developed protocols feature easily controllable selectivity, mild reaction conditions, clean sustainable oxidant (air), valuable products that are structurally diverse. In addition, utility was showcased their facile diverse transformations into synthetically biologically interesting compounds.

Язык: Английский

Процитировано

27

Visible-Light Photocatalyzed C3–H Alkylation of 2H-Indazoles/Indoles with Sulfoxonium Ylides via Diversified Mechanistic Pathways DOI
Altman Yuzhu Peng, Yujing Wang, Kaifeng Wang

и другие.

ACS Catalysis, Год журнала: 2024, Номер 14(2), С. 1193 - 1204

Опубликована: Янв. 9, 2024

Herein, the C3–H alkylation of 2H-indazoles and indoles with sulfoxonium ylides is developed under visible-light photocatalysis. This protocol employs easily accessible reagents, a wide range 2H-indazoles, indoles, are suitable for this reaction to afford desired products benign conditions. Synergistic experimental computational studies suggest that involving photocatalysis could proceed via different mechanistic pathways. For C3-alkylation triplet energy transfer pathway proposed quenching excited photocatalyst. Subsequently, formed state undergo radical attack on C═S moiety ylides. After dissociation DMSO 1,2-H migration, final product be yielded. However, such not applicable indoles. Instead, converted C-centered in presence KH2PO4 photoredox The can C3-site thus lead

Язык: Английский

Процитировано

13

Direct radical alkylation and acylation of 2H-indazoles using substituted Hantzsch esters as radical reservoirs DOI
Li Liu,

Pengxing Jiang,

Yongguo Liu

и другие.

Organic Chemistry Frontiers, Год журнала: 2020, Номер 7(16), С. 2278 - 2283

Опубликована: Янв. 1, 2020

A platform approach for the direct synthesis of 3-substituted 2H-indazole derivatives has been developed using a Ag(i)/Na2S2O8 system.

Язык: Английский

Процитировано

56

Photocatalytic transition-metal-free direct 3-alkylation of 2-aryl-2H-indazoles in dimethyl carbonate DOI
Chunhua Ma,

Zhi‐Wen Feng,

Jing Li

и другие.

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(13), С. 3286 - 3291

Опубликована: Янв. 1, 2021

A general transition-metal-free photocatalytic decarboxylative 3-alkylation reaction of 2-aryl-2H-indazoles was developed under visible-light irradiation mild conditions.

Язык: Английский

Процитировано

35