The ruthenium-catalyzed <i>meta</i>-selective C–H nitration of various azole ring-substituted arenes

Zhang, Dong; Gao, Di; Cai, Jinlin; Wu, Xiaoyu; Qin, Huiying; Qiao, Kai; Liu, Chengkou; Fang, Zheng

doi:10.1039/c9ob01930h

Cited by 9 publications

(10 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…68 In a 2019 study, Fang, Guo, and co-workers achieved meta-selective nitrations of arenes 24 directed by pyrazoles, thiazoles, or removable oxazolines under ruthenium catalysis using AgNO 2 (135) as the nitrogen source (Scheme 43). 69 Catalytic amounts of [HPCy 3 ][BF 4 ] as a ligand and PivOH as an additive were crucial for high efficacies.…”

Section: Special Topic Synthesismentioning

confidence: 99%

Remote C–H Functionalizations by Ruthenium Catalysis

Korvorapun¹,

Samanta²,

Rogge³

et al. 2021

Synthesis

View full text Add to dashboard Cite

Synthetic transformations of otherwise inert C–H bonds have emerged as a powerful tool for molecular modifications during the last decades, with broad applications towards pharmaceuticals, material sciences and crop protection. Consistently, a key challenge in C–H activation chemistry is the full control of site-selectivity. In addition to substrate control through steric hindrance or kinetic acidity of C–H bonds, one important approach for the site-selective C–H transformation of arenes is the use of chelation-assistance through directing groups, therefore leading to proximity-induced ortho-C–H metalation. In contrast, more challenging remote C–H activations at the meta- or para-positions continue to be scarce. Within this review, we demonstrate the distinct character of ruthenium catalysis for remote C–H activations until March 2021, highlighting among others late-stage modifications of bio-relevant molecules. Moreover, we highlight important mechanistic insights by experiments and computation, highlighting the key importance of carboxylate-assisted C–H activation with ruthenium(II) complexes.

show abstract

Section: Special Topic Synthesismentioning

confidence: 99%

Remote C–H Functionalizations by Ruthenium Catalysis

Korvorapun¹,

Samanta²,

Rogge³

et al. 2021

Synthesis

View full text Add to dashboard Cite

show abstract

“…After the initial report by Zhang group on the meta-nitration of phenyl pyridine in 2015, three years later Peng group published a similar approach of Rucatalyzed meta-nitration of 2-arylbenzothiazoles and 2-arylthiazoles. 218 Cu(NO 3 ) 3 .3H 2 O was employed as the nitrating reagent and a range of 2-arylbenzothiazoles and 2-arylthiazoles were tested to the methodology. Peng group also performed selective reduction of the meta-nitrated product which after a sequence of steps led to the formation of compound enabled for promising therapeutic leads for Human African Trypanosomiasis.…”

Section: Ruthenium-catalyzed Distal C−h Functionalization Of Aromatic...mentioning

confidence: 83%

“…Consequently, incorporating nitration selectively at the distal meta -position of arenes proves an effective and important challenge. After the initial report by Zhang group on the meta -nitration of phenyl pyridine in 2015, three years later Peng group published a similar approach of Ru-catalyzed meta -nitration of 2-arylbenzothiazoles and 2-arylthiazoles . Cu(NO 3 ) 3 .3H 2 O was employed as the nitrating reagent and a range of 2-arylbenzothiazoles and 2-arylthiazoles were tested to the methodology.…”

Section: Ruthenium-catalyzed Distal C–h Functionalization Of Aromatic...mentioning

confidence: 99%

Toolbox for Distal C–H Bond Functionalizations in Organic Molecules

et al. 2021

View full text Add to dashboard Cite

Transition-metal-catalyzed C−H activation has developed a contemporary approach to the omnipresent area of retrosynthetic disconnection. Scientific researchers have been tempted to take the help of this methodology to plan their synthetic discourses. This paradigm shift has helped in the development of industrial units as well, making the synthesis of natural products and pharmaceutical drugs step-economical. In the vast zone of C−H bond activation, the functionalization of proximal C−H bonds has gained utmost popularity. Unlike the activation of proximal C−H bonds, the distal C−H functionalization is more strenuous and requires distinctly specialized techniques. In this review, we have compiled various methods adopted to functionalize distal C−H bonds, mechanistic insights within each of these procedures, and the scope of the methodology. With this review, we give a complete overview of the expeditious progress the distal C−H activation has made in the field of synthetic organic chemistry while also highlighting its pitfalls, thus leaving the field open for further synthetic modifications.

show abstract

“…Finally, ligand exchange between‐4 and CF 3 COOH gives desired nitro product. Wide functional group tolerance, moderate to excellent yield and good meta selectivity are notable advantages of this technique [31] …”

Section: Nitration By C−h Activation Methodsmentioning

confidence: 99%

“…Herein, RuÀ C σ bond act as a fridlecraft type ortho/para directing group, which incorporate with NO 2 and finally deprotonation of B-complex resulted meta nitro product. [30] Ruthenium catalyzed meta-selective CÀ H nitration reported by Zhang group using Ru 3 (CO) 12 [31] Iron promoted C3-H nitration of indazole have been developed by murugan et al (Scheme 24) Herein, for the optimization of the reaction authors employs various solvents such as acetonitrile, dichloroethane, CHCl 3 , DMF, DMSO, Dioxane, Toluene, Water, methanol, ethanol. Among them dichloroethane solvent and TEMPO (2,2,6,6-tetramethylpipreridin-1-yl)oxyl proven best system in terms of yield and reaction time.…”

Section: Nitration Through Cà H Activationmentioning

confidence: 99%

Synthetic Protocols for Aromatic Nitration: A Review

Patel

2021

ChemistrySelect

View full text Add to dashboard Cite

Nitration of aromatic compounds represents a powerful and widely used transformation that allows introducing nitro group into aromatic systems. New synthetic strategies for aromatic nitration are deeply needed, including highly efficient and selective nitration methods. Aromatic nitration plays an important part in the industry, as the main use of nitration is to produce important products such as dyes & intermediate compounds, drugs, and Agrochemicals. The electrophilic aromatic nitration is most studied and important transformation in industrial process. This review will describe different possible methodologies that apply to this fundamental transformation with special attention to the most recent development that lasted from 2017–2020. The main pros and cons of recent nitration methods are briefly described with their specific reaction mechanism and highlighting the most important feature of the present aromatic nitration method.

show abstract

The ruthenium-catalyzed meta-selective C–H nitration of various azole ring-substituted arenes

Abstract: The efficient and gentle ruthenium-catalyzed meta-selective CAr–H nitration of azole ring substituted arenes has been developed.

Cited by 9 publications

References 45 publications

Remote C–H Functionalizations by Ruthenium Catalysis

Remote C–H Functionalizations by Ruthenium Catalysis

Toolbox for Distal C–H Bond Functionalizations in Organic Molecules

Synthetic Protocols for Aromatic Nitration: A Review

Contact Info

Product

Resources

About