Recent Trends in Group 9 Catalyzed C–H Borylation Reactions: Different Strategies To Control Site-, Regio-, and Stereoselectivity

Synthesis, Journal Year: 2021, Volume and Issue: 54(15), P. 3482 - 3498

Published: Dec. 2, 2021

Abstract Organoboron compounds continue contributing substantially to advances in organic chemistry with their increasing role as both synthetic intermediates and target for medicinal chemistry. Particularly attractive methods synthesis are based on the direct borylation of C–H bonds available starting materials since no additional pre-functionalization steps required. However, due high abundance similar reactivity molecules, synthetically useful protocols demand sophisticated strategies achieve regio- stereoselectivity. For this purpose, selective transition-metal-based catalysts have been developed, group 9 centered being among most commonly utilized. Recently, a multitude diverse has developed push boundaries reactions respect enantioselectivity. Herein, we provide an overview approaches arenes, alkenes, alkanes focus recent literature. Lastly, outlook is given assess future potential field. 1 Introduction 1.1 Mechanistic Considerations 1.2 Selectivity Issues Borylation 1.3 Different Modes Action Employing Directing Group Strategies 1.4 Scope Aim Short Review 2 Trends Reactions 2.1 Photoinduced Catalysis 2.2 Transfer 2.3 Lewis Acid Mediated 2.4 Directed Metalation 2.5 Miscellaneous 2.6 Electrostatic Interactions 2.7 Hydrogen Bonding 3 Conclusion Outlook

Language: Английский

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Metal and Metal Oxide Nanoparticles Catalyzed C–H Activation for C–O and C–X (X = Halogen, B, P, S, Se) Bond Formation

Catalysts, Journal Year: 2022, Volume and Issue: 13(1), P. 16 - 16

Published: Dec. 22, 2022

The direct functionalization of an inactivated C–H bond has become attractive approach to evolve toward step-economy, atom-efficient and environmentally sustainable processes. In this regard, the design preparation highly active metal nanoparticles as efficient catalysts for activation under mild reaction conditions still continue be investigated. This review focuses on un-activated C(sp3)–H, C(sp2)–H C(sp)–H bonds exploiting oxide C–O C–X (X = Halogen, B, P, S, Se) formation, resulting in more access industrial production.

Language: Английский

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OrthoC−H Functionalizations of 2‐Aryl‐2H‐Indazoles

The Chemical Record, Journal Year: 2022, Volume and Issue: 22(11)

Published: July 22, 2022

Abstract C−H Functionalization is ubiquitously considered as a powerful, efficient and handy tool for installing various functional groups in complex organic heterocycles an easier step‐economic way. Similarly, indazole endowed potent heterocycle eminent its profound impact biological, medicinal industrial chemistry. In this scenario, functionalization at the selective ortho position of 2‐arylindazole assistance metal catalyst also becoming appealing approach synthetic This review addressed recent findings developments on 2‐aryl‐2 H ‐indazazoles with literature coverage extending from 2018 to May 2022.

Language: Английский

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An Introductory Overview of C–H Bond Activation/ Functionalization Chemistry with Focus on Catalytic C(sp3)–H Bond Borylation

KIMIKA, Journal Year: 2021, Volume and Issue: 32(1), P. 70 - 109

Published: May 13, 2021

The direct and selective functionalization of C–H bonds provides novel disconnections innovative strategies to streamline the synthesis molecules with diverse complexities. However, despite significant advances in elaboration techniques for activation, utilization unactivated C(sp3)–H remains challenging. In particular, asymmetric transformation is underdeveloped owing lack catalytic systems that can competently discriminate among ubiquitous organic molecules. This short review aims outline challenges giving a general non-exhaustive explanatory approach. Current on basis substrates reaction mechanisms are summarized Section 1. Examples enantioselective bond transformations then given 2. Finally, 3, an current methodologies towards borylation described showcase importance developing chemistry. While we try cover all excellent reports available literature this topic, any omissions unintentional, taking note most representative examples available.

Language: Английский

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S,O‐Ligand Promoted meta‐C−H Arylation of Anisole Derivatives via Palladium/Norbornene Catalysis

Angewandte Chemie, Journal Year: 2022, Volume and Issue: 134(31)

Published: May 31, 2022

Abstract Reversing the conventional site‐selectivity of C−H activation processes provides new retrosynthetic disconnections to otherwise unreactive bonds. Here, we report a catalytic system based on palladium/norbornene and an S,O‐ligand for meta ‐C−H arylation aryl ethers that significantly outperforms previously reported systems. We demonstrate unique ability this employ alkoxyarene substrates bearing electron donating withdrawing substituents. Additionally, ortho ‐substituted are well tolerated, overcoming “ constraint”, which is necessity have ‐substituent achieve high reaction efficiency, by enlisting novel norbornene mediators. Remarkably, first time monoarylation alkoxyarenes achieved efficiently enabling subsequent introduction second, different coupling partner rapidly furnish unsymmetrical terphenyls. Further insight into mechanism was isolation characterization some Pd‐complexes—before after activation—prior evaluation their respective activities.

Language: Английский

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Conjugated Olefin Enabled Rollover Cyclometallation of Distant C‐H Bonds: Regioselective Annulation of o‐Alkenyl Phenols with Alkynes

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(70)

Published: Oct. 11, 2023

Although challenging, the distant C-H functionalization with precision is quite rewarding and has long been intriguing. Tailoring an appropriate template accomplishes job but prerequisite sets limitation. We herein unveil our discovery of annulation alkynes on to two (from directing group) bonds through rollover cyclometallation assisted by conjugated C=C bond. The follows a concomitant cyclization rare triple functionalization. totally regioselective array unsymmetrical alkynes, taking leverage extended conjugation or tertiary hydroxyl co-ordination. mechanism supported control experiments, KIE & labelling studies Mass spectrometry.

Language: Английский

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Palladium(II)-Catalyzed Remote meta-C–H Functionalization of Arenes Enabled by Multitasking Oxyamides as the Linker

Organic Letters, Journal Year: 2023, Volume and Issue: 25(24), P. 4416 - 4421

Published: June 12, 2023

A palladium-catalyzed olefination of meta-C–H bonds in arenes containing oxyamides using a nitrile template as the directing group has been established. The methodology exhibited high meta-selectivity and tolerated different functional groups such benzyloxyamides olefin substrates. desired products were obtained good yields. This approach enabled modification natural drugs was also applicable on gram-scale. Furthermore, readily removed by selective cleavage amide bond or O–N to obtain meta-functionalized hydroxylamines benzyl alcohols. proposed method holds great potential for design novel drugs.

Language: Английский

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Ru-Catalyzed meta-Selective Aryl sp2C–H Bond Alkylation of Biologically Important Heterocycles to Access C–C Bond

Topics in heterocyclic chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Language: Английский

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Development of Site-Selective C-H Transformations Using Noncovalent Interaction

Journal of Synthetic Organic Chemistry Japan, Journal Year: 2024, Volume and Issue: 82(10), P. 954 - 964

Published: Oct. 1, 2024

The control of site-selectivity is important to obtain the desired products efficiently in synthetic organic chemistry. Because there are many C-H bonds with similar reactivities molecules, it was difficult promote site-selective transformations without using directing groups. In this award article, I describe new strategies noncovalent interactions, such as hydrogen bond, Lewis acid-base interaction and electrostatic interaction, between catalyst substrate. As a result, highly have been achieved. By substrate reagent, ortho-selective C(sp2)-H borylation silylation were addition, trifluoromethylation developed by inclusion aromatic into cyclodextrin supramolecular interaction.

Language: Английский

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Recent Advances in Transition-Metal-Catalyzed Selective C–H Alkoxycarbonyldifluoromethylation Reactions of Aromatic Substrates

Synthesis, Journal Year: 2021, Volume and Issue: 53(20), P. 3699 - 3715

Published: June 2, 2021

Abstract Fluorine is well-known as a very special element. Approximately 30% of agrochemicals and 20% all drugs contain fluorine; most those compounds have unique functions in biochemistry, pharmacy, bioscience containing alkoxycarbonyldifluoromethyl functional groups often irreplaceable roles. Therefore, the selective introduction alkoxycarbonyldifluoromethylated into various aromatic substrates has significant practical application. This review describes recent advances alkoxycarbonyldifluoromethylation by using different catalytic strategies (cyclometalated ruthenium complex, transient regulating visible-light-induced strategies). 1 Introduction 2 para-C–H Alkoxycarbonyldifluoromethylation Aromatic Derivatives 2.1 Ruthenium Catalysis 2.2 Palladium 2.3 Visible-Light 2.4 Iron 3 meta-C–H 3.1 3.2 4 The Influence Transition Metals Directing Groups on Site Selectivity 4.1 4.2 5 Conclusions

Language: Английский

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