Intramolecular Reductive Cyclization of <i>o</i>-Nitroarenes via Biradical Recombination

Lu, Cong; Su, Zhishan; Dong, Jing; Jin, Songyang; Xie, Lijuan; Li, Liangrui; Zheng, Ke

doi:10.1021/acs.orglett.9b00191

Cited by 46 publications

(24 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…83 In 2019, Zheng reported a visible-lightmediated thiourea-catalyzed intramolecular reductive cyclization of ortho-substituted nitroarenes to produce polycyclic quinazolinones (Scheme 24). 82 Their investigations showed that making changes to the structure of the thiourea catalyst impacted the yield of the transformation. No reaction was observed in the absence of light, and the yield was severely attenuated when the silane was omitted or when air was used in place of the N 2 atmosphere.…”

Section: Short Review Synthesis 9 Visible-light-driven Reductive Amin...mentioning

confidence: 99%

Recent Advances to Mediate Reductive Processes of Nitroarenes Using Single-Electron Transfer, Organomagnesium, or Organozinc Reagents

Zhu¹,

Driver²

2022

Synthesis

View full text Add to dashboard Cite

Recent advances in the development of reductive reactions of nitroarenes using organomagnesium-, organozinc-, and single electron transfer reagents is discussed within this review. The review is divided into the following sections: 1 Introduction 2 Organomagnesium-mediated reductive reactions 3 Organozinc- and zinc-mediated reductive reactions 4 Iodine-catalyzed redox cyclizations 5 Titanium(III)-mediated reductive cyclizations 6 Sulfur-mediated reductive reactions 7 Alkoxide-mediated reductive reactions 8 4,4'-Bipyridine-mediated reductive reactions 9 Visible light-driven reductive amination reactions 10 Electrochemical reductive reactions 11 Conclusion

show abstract

Section: Short Review Synthesis 9 Visible-light-driven Reductive Amin...mentioning

confidence: 99%

Recent Advances to Mediate Reductive Processes of Nitroarenes Using Single-Electron Transfer, Organomagnesium, or Organozinc Reagents

Zhu¹,

Driver²

2022

Synthesis

View full text Add to dashboard Cite

show abstract

“…There are cyclizations using Pd-catalysis with CO [ 68 ] or H 2 [ 69 ]. Recent metal-free conditions use visible light, phenylthiourea as catalyst and PhSiH 3 as reductant [ 70 ], and electrochemical cyclizations [ 52 ]. Thermal annulation using nitrobenzene substrates are possible with neat 1,2,3,4-tetrahydroisoquinoline (THIQ) ( Scheme 20 a) [ 71 ], and cyclizations occur using I 2 /HCO 2 H [ 72 ] ( Scheme 20 b).…”

Section: Syntheses Of Ring-fused Benzimidazoles and Imidazobenzimidazolesmentioning

confidence: 99%

Advances in the Synthesis of Ring-Fused Benzimidazoles and Imidazobenzimidazoles

et al. 2021

View full text Add to dashboard Cite

This review article provides a perspective on the synthesis of alicyclic and heterocyclic ring-fused benzimidazoles, imidazo[4,5-f]benzimidazoles, and imidazo[5,4-f]benzimidazoles. These heterocycles have a plethora of biological activities with the iminoquinone and quinone derivatives displaying potent bioreductive antitumor activity. Synthesis is categorized according to the cyclization reaction and mechanisms are detailed. Nitrobenzene reduction, cyclization of aryl amidines, lactams and isothiocyanates are described. Protocols include condensation, cross-dehydrogenative coupling with transition metal catalysis, annulation onto benzimidazole, often using CuI-catalysis, and radical cyclization with homolytic aromatic substitution. Many oxidative transformations are under metal-free conditions, including using thermal, photochemical, and electrochemical methods. Syntheses of diazole analogues of mitomycin C derivatives are described. Traditional oxidations of o-(cycloamino)anilines using peroxides in acid via the t-amino effect remain popular.

show abstract

“…[39] In 2019, Zhang and co-workers firstly reported a visible-lightinduced intramolecular reductive cyclization of o-nitrobenzamides 50 for the synthesis of useful quinazolinone derivatives 51 (Scheme 25). [40] This transformation uses thiourea as a catalyst and silane as a terminal reductant under 10 W purple LED. A wild range of onitrobenzamides participated in the reaction, affording a series of polycyclic quinazolinone derivatives in good to high yields.…”

Section: Other Processes Involve Reductive Coupling Of Nitro Compoundmentioning

confidence: 99%

Recent Progress on Reductive Coupling of Nitroarenes by Using Organosilanes as Convenient Reductants

et al. 2020

View full text Add to dashboard Cite

Nitroarenes are stable, low-cost, and readily available starting materials. The directly utilize nitroarenes in synthetically valuable CÀ N bond formation is of great significance, because the prereduction step to corresponding amines can be avoided. Previously, phosphines and carbon monoxide (CO) are the most widely used reductants in the reductive cyclization or/and carbonylation of nitroarenes. Currently, much attention has been attracted to organosilanes as new potential reducing agents, not only because they are inexpensive, easy-to-handle, and mild reagents, but also various novel reaction models of nitroarenes have been explored. In this review, we mainly summarize the recent progress on the reductive coupling of nitroarenes by using organosilanes as the end reductants. We hope that a deep understanding of the reaction model and underlying working mechanism can provide a timely guideline for researchers who are interested in this fantastic area, leading to further exploration of practical and efficient reductive coupling of nitroarenes for CÀ N bond formation and N-heterocycle synthesis. 1. Introduction 2. Reduction of Nitro Compounds to Primary Amines by Organosilanes 3. Fe-Catalyzed Reductive Coupling of Nitroarenes for CÀ N Bond Formation and N-Heterocycle Synthesis 4. Ni-catalyzed Reductive Coupling of Nitroarenes for CÀ N Bond Formation 5. Cu-catalyzed Reductive Coupling of Nitroarenes for CÀ N Bond Formation and N-Heterocycle Synthesis 6. Organophosphorus-Catalyzed Reductive CÀ N Bond Formation and N-Heterocycles Synthesis from Nitroarenes 7. Other Processes Involve Reductive Coupling of Nitro Compounds by Organosilane Reductants 8.

show abstract

Intramolecular Reductive Cyclization of o-Nitroarenes via Biradical Recombination

Cited by 46 publications

References 61 publications

Recent Advances to Mediate Reductive Processes of Nitroarenes Using Single-Electron Transfer, Organomagnesium, or Organozinc Reagents

Recent Advances to Mediate Reductive Processes of Nitroarenes Using Single-Electron Transfer, Organomagnesium, or Organozinc Reagents

Advances in the Synthesis of Ring-Fused Benzimidazoles and Imidazobenzimidazoles

Recent Progress on Reductive Coupling of Nitroarenes by Using Organosilanes as Convenient Reductants

Contact Info

Product

Resources

About