Iron-Catalyzed C–H Bond Activation

Chemical Reviews, Год журнала: 2017, Номер 117(13), С. 9086 - 9139

Опубликована: Апрель 5, 2017

Catalytic C-H bond activation, which was an elusive subject of chemical research until the 1990s, has now become a standard synthetic method for formation new C-C and C-heteroatom bonds. The potential activation first described ruthenium catalysis is widely exploited by use various precious metals. Driven increasing interest in utilization ubiquitous metals that are abundant nontoxic, iron rapidly growing area research, iron-catalyzed been most actively explored recent years. In this review, we summarize development stoichiometric long history, catalytic functionalization, emerged about 10 years ago. We focus review on reactions take place via reactive organoiron intermediates, excluded those as Lewis acid or radical initiator. contents categorized type cleaved formed thereafter, it covers simple substrates possessing directing group anchors catalyst to substrate, providing overview iron-mediated reported literature October 2016.

Язык: Английский

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Bidentate Directing Groups: An Efficient Tool in C–H Bond Functionalization Chemistry for the Expedient Construction of C–C Bonds

Chemical Reviews, Год журнала: 2020, Номер 120(3), С. 1788 - 1887

Опубликована: Янв. 6, 2020

During the past decades, synthetic organic chemistry discovered that directing group assisted C–H activation is a key tool for expedient and siteselective construction of C–C bonds. Among various strategies, bidentate groups are now recognized as one most efficient devices selective functionalization certain positions due to fact its metal center permits fine, tunable, reversible coordination. The family permit types assistance be achieved, such N,N-dentate, N,O-dentate, N,S-dentate auxiliaries, which categorized based on coordination site. In this review, we broadly discuss bond reactions formation bonds with aid groups.

Язык: Английский

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Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C–H Bonds Elaboration

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 1875 - 1924

Опубликована: Авг. 6, 2021

Direct photocatalyzed hydrogen atom transfer (d-HAT) can be considered a method of choice for the elaboration aliphatic C–H bonds. In this manifold, photocatalyst (PCHAT) exploits energy photon to trigger homolytic cleavage such bonds in organic compounds. Selective bond may achieved by judicious abstractor (key parameters are electronic character and molecular structure), as well reaction additives. Different classes PCsHAT available, including aromatic ketones, xanthene dyes (Eosin Y), polyoxometalates, uranyl salts, metal-oxo porphyrin tris(amino)cyclopropenium radical dication. The processes (mainly C–C formation) most cases carried out under mild conditions with help visible light. aim review is offer comprehensive survey synthetic applications d-HAT.

Язык: Английский

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Enantioselective C(sp ³ )‒H bond activation by chiral transition metal catalysts

Science, Год журнала: 2018, Номер 359(6377)

Опубликована: Фев. 16, 2018

Left- or right-handed C–H bond activation Although organic compounds consist mostly of carbon and hydrogen atoms, strategies for chemical synthesis have traditionally targeted the handful more reactive interspersed oxygens, nitrogens, halogens. Modifying bonds directly is a appealing approach, but selectivity remains challenge. Saint-Denis et al. review recent progress in using transition metal catalysis to break just one two mirror-image then append complex substituent its place. Ligand design has proven crucial differentiate these otherwise similar variety molecular settings. Science , this issue p. eaao4798

Язык: Английский

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Photoredox-Catalyzed C–H Functionalization Reactions

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 1925 - 2016

Опубликована: Сен. 29, 2021

The fields of C–H functionalization and photoredox catalysis have garnered enormous interest utility in the past several decades. Many different scientific disciplines relied on strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, fine chemical synthesis. In this Review, we highlight use reactions. We separate review into inorganic/organometallic catalysts organic-based catalytic systems. Further subdivision by reaction class─either sp2 or sp3 functionalization─lends perspective tactical for these methods synthetic applications.

Язык: Английский

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Recent Advances in Minisci‐Type Reactions

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(39), С. 13666 - 13699

Опубликована: Март 20, 2019

Abstract Reactions that involve the addition of carbon‐centered radicals to basic heteroarenes, followed by formal hydrogen atom loss, have become widely known as Minisci‐type reactions. First developed into a useful synthetic tool in late 1960s Minisci, this reaction type has been constant use over last half century chemists seeking functionalize heterocycles rapid and direct manner, avoiding need for de novo heterocycle synthesis. Whilst originally protocols radical generation remain active today, they joined recent years new array strategies allow wider variety precursors often operate under milder more benign conditions. The surge interest transformations based on free reactivity meant numerous choices are now available chemist looking utilize reaction. Radical‐generation methods photoredox catalysis electrochemistry approaches which thermal cleavage or situ reactive precursors. This review will cover remarkably large body literature appeared topic decade an attempt provide guidance chemist, well perspective both challenges overcome those still remain. As logical classification advances nature precursor, with most concerned, control various selectivity aspects associated reactions also be discussed.

Язык: Английский

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Complementary Strategies for Directed C(sp³)−H Functionalization: A Comparison of Transition‐Metal‐Catalyzed Activation, Hydrogen Atom Transfer, and Carbene/Nitrene Transfer

Angewandte Chemie International Edition, Год журнала: 2017, Номер 57(1), С. 62 - 101

Опубликована: Дек. 5, 2017

Abstract The functionalization of C(sp 3 )−H bonds streamlines chemical synthesis by allowing the use simple molecules and providing novel synthetic disconnections. Intensive recent efforts in development new reactions based on C−H have led to its wider adoption across a range research areas. This Review discusses strengths weaknesses three main approaches: transition‐metal‐catalyzed activation, 1, n ‐hydrogen atom transfer, carbene/nitrene for directed unactivated bonds. For each strategy, scope, reactivity different bonds, position reacting relative directing group, stereochemical outcomes are illustrated with examples literature. aim this is provide guidance inspire future area.

Язык: Английский

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C–H Activation: Toward Sustainability and Applications

ACS Central Science, Год журнала: 2021, Номер 7(2), С. 245 - 261

Опубликована: Фев. 2, 2021

Since the definition of "12 Principles Green Chemistry" more than 20 years ago, chemists have become increasingly mindful need to conserve natural resources and protect environment through judicious choice synthetic routes materials. The direct activation functionalization C–H bonds, bypassing intermediate functional group installation is, in abstracto, step atom economic, but numerous factors still hinder sustainability large-scale applications. In this Outlook, we highlight research areas seeking overcome challenges activation: pursuit abundant metal catalysts, avoidance static directing groups, replacement oxidants, introduction bioderived solvents. We close by examining progress made subfield aryl borylation from its origins, highly efficient precious Ir-based systems, emerging 3d catalysts. future growth field will depend on industrial uptake, thus urge researchers strive toward sustainable activation.

Язык: Английский

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Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 2752 - 2906

Опубликована: Авг. 10, 2021

Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing plethora opportunities to synthetic organic chemists. However, performing photochemical transformation can be quite challenge because various issues related the delivery photons. These challenges barred widespread adoption steps industry. past decade, several technological innovations led more reproducible, selective, and scalable photoinduced reactions. Herein, we provide comprehensive overview these exciting advances, including flow chemistry, high-throughput experimentation, reactor design scale-up, combination photo- electro-chemistry.

Язык: Английский

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Walking Metals for Remote Functionalization

ACS Central Science, Год журнала: 2018, Номер 4(2), С. 153 - 165

Опубликована: Фев. 8, 2018

The distant and selective activation of unreactive C–H C–C bonds remains one the biggest challenges in organic chemistry. In recent years, development remote functionalization has received growing interest as it allows for rather challenging from initiation point by means a "metal-walk". A "metal-walk" or "chain-walk" is defined an iterative series consecutive 1,2- 1,3-hydride shifts metal complex along single hydrocarbon chain. With this approach, simple building blocks mixtures thereof can be transformed into scaffolds convergent unified strategy. variety catalytic systems have been developed refined over past decade ranging late-transition-metal complexes to more sustainable iron- cobalt-based systems. As possibilities field are slowly unfolding, area research will contribute considerably provide solutions yet unmet synthetic challenges.

Язык: Английский

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