3d Transition Metals for C–H Activation

Chemical Reviews, Год журнала: 2018, Номер 119(4), С. 2192 - 2452

Опубликована: Ноя. 27, 2018

C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these functionalizations required precious 4d or 5d transition metal catalysts. Given cost-effective sustainable nature earth-abundant first row metals, development less toxic, inexpensive 3d catalysts gained considerable recent momentum a significantly more environmentally-benign economically-attractive alternative. Herein, we provide comprehensive overview on until summer 2018.

Язык: Английский

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A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

Chemical Society Reviews, Год журнала: 2018, Номер 47(17), С. 6603 - 6743

Опубликована: Янв. 1, 2018

The present review is devoted to summarizing the recent advances (2015-2017) in field of metal-catalysed group-directed C-H functionalisation. In order clearly showcase molecular diversity that can now be accessed by means directed functionalisation, whole organized following directing groups installed on a substrate. Its aim comprehensive reference work, where specific group easily found, together with transformations which have been carried out it. Hence, primary format this schemes accompanied concise explanatory text, are ordered sections according their chemical structure. feature typical substrates used, products obtained as well required reaction conditions. Importantly, each example commented respect most important positive features and drawbacks, aspects such selectivity, substrate scope, conditions, removal, greenness. targeted readership both experts functionalisation chemistry (to provide overview progress made last years) and, even more so, all organic chemists who want introduce way thinking for design straightforward, efficient step-economic synthetic routes towards molecules interest them. Accordingly, should particular also scientists from industrial R&D sector. overall goal promote application reactions outside research dedicated method development establishing it valuable archetype contemporary R&D, comparable role cross-coupling play date.

Язык: Английский

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Transition‐Metal‐Mediated and ‐Catalyzed C−F Bond Activation by Fluorine Elimination

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(2), С. 390 - 402

Опубликована: Июнь 28, 2018

Abstract The activation of carbon–fluorine (C−F) bonds is an important topic in synthetic organic chemistry. Metal‐mediated and ‐catalyzed elimination β‐ or α‐fluorine proceeds under milder conditions than oxidative addition to C−F bonds. initiated from organometallic intermediates having fluorine substituents on carbon atoms β α metal centers, respectively. Transformations through these processes (C−F bond cleavage), which are typically preceded by carbon–carbon (or carbon–heteroatom) formation, have been increasingly developed the past five years as methods. In this Minireview, we summarize applications transition‐metal‐mediated chemistry a historical perspective with early studies systematic recent studies.

Язык: Английский

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(Pentamethylcyclopentadienyl)cobalt(III)‐Catalyzed C–H Bond Functionalization: From Discovery to Unique Reactivity and Selectivity

Advanced Synthesis & Catalysis, Год журнала: 2017, Номер 359(8), С. 1245 - 1262

Опубликована: Март 16, 2017

Abstract High‐valent (pentamethylcyclopentadienyl)cobalt(III) [Cp*Co(III)] catalysts were found as inexpensive alternatives to (pentamethylcyclopentadienyl)rhodium(III) [Cp*Rh(III)] in the field of C—H bond functionalization, and applied a variety transformations. In this review, after discovery early examples Cp*Co(III)‐catalyzed functionalization are summarized, unique reactivity selectivity Cp*Co(III) differences between cobalt rhodium catalysis intensively discussed. Such assumed be caused by lower electronegativity, hard nature, smaller ionic radius cobalt. magnified image

Язык: Английский

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Recent advances in positional-selective alkenylations: removable guidance for twofold C–H activation

Organic Chemistry Frontiers, Год журнала: 2017, Номер 4(7), С. 1435 - 1467

Опубликована: Янв. 1, 2017

Recent advances in transition-metal catalyzed positional-selective alkenylations via twofold C–H activation directed by removable or traceless directing groups are reviewed.

Язык: Английский

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Experimental and Theoretical Studies on Rhodium-Catalyzed Coupling of Benzamides with 2,2-Difluorovinyl Tosylate: Diverse Synthesis of Fluorinated Heterocycles

Journal of the American Chemical Society, Год журнала: 2017, Номер 139(9), С. 3537 - 3545

Опубликована: Фев. 8, 2017

Fluorinated heterocycles play an important role in pharmaceutical and agrochemical industries. Herein, we report on the synthesis of four types fluorinated via rhodium(III)-catalyzed C—H activation arenes/alkenes versatile coupling with 2,2-difluorovinyl tosylate. With N-OMe benzamide being a directing group (DG), reaction delivered monofluorinated alkene retention tosylate functionality. Subsequent one-pot acid treatment allowed efficient 4-fluoroisoquinolin-1(2H)-ones 5-fluoropyridin-2(1H)-ones. When N—OPiv benzamides were used, however, [4 + 2] cyclization occurred to provide gem-difluorinated dihydroisoquinolin-1(2H)-ones. Synthetic applications have been demonstrated ready availability both arene partner highlighted synthetic potentials these protocols. Mechanistically, two processes share common process involving N—H deprotonation, activation, olefin insertion form 7-membered rhodacycle. Thereafter, different pathways featuring β-F elimination C—N bond formation are followed basis density functional theory (DFT) studies. These DG-dependent led open chain products, respectively. The mechanistic rationale was supported by detailed DFT In particular, origins intriguing selectivity competing versus elucidated. It found that is facile event proceeds syn-coplanar transition state low energy barrier. migratory Rh—C(alkyl) into Rh(V) amido species. reactions, turnover-limiting, which stays good agreement experimental

Язык: Английский

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Nickel-Catalyzed Defluorinative Reductive Cross-Coupling of gem-Difluoroalkenes with Unactivated Secondary and Tertiary Alkyl Halides

Journal of the American Chemical Society, Год журнала: 2017, Номер 139(36), С. 12632 - 12637

Опубликована: Авг. 29, 2017

Herein, we described a nickel-catalyzed monofluoroalkenylation through defluorinative reductive cross-coupling of gem-difluoroalkenes with alkyl halides. Key to the success this strategy is combination C–F cleavage halides activation. This reaction enables convenient synthesis large variety functionalized monofluoroalkenes under mild conditions broad functional group compatibility and excellent Z-selectivity. The Ni catalysis (Bpin)2/K3PO4 as terminal reductant promoted efficient C(sp2)–C(sp3) formation especially generation all-carbon quaternary centers high chemoselectivity.

Язык: Английский

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C–H functionalization by high-valent Cp*Co(iii) catalysis

Chemical Communications, Год журнала: 2017, Номер 53(22), С. 3165 - 3180

Опубликована: Янв. 1, 2017

Significant progress has been accomplished in directed C–H functionalization through the use of earth-abundant and inexpensive first-row transition metals.

Язык: Английский

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Direct Functionalization of C−H Bonds by Iron, Nickel, and Cobalt Catalysis

Chemistry - A European Journal, Год журнала: 2017, Номер 23(39), С. 9206 - 9232

Опубликована: Июнь 7, 2017

Abstract Non‐precious‐metal‐catalyzed reactions are of increasing importance in chemistry due to the outstanding ecological and economic properties these metals. In subfield metal‐catalyzed direct C−H functionalization reactions, recent years have shown an number publications dedicated this topic. Nickel, cobalt, last but not least iron, started enter a field which was long dominated by precious metals such as palladium, rhodium, ruthenium, iridium. The present review article summarizes development iron‐, nickel‐, cobalt‐catalyzed until end 2016, discusses scope limitations transformations.

Язык: Английский

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C–F/C–H Functionalization by Manganese(I) Catalysis: Expedient (Per)Fluoro-Allylations and Alkenylations

ACS Catalysis, Год журнала: 2017, Номер 7(6), С. 4209 - 4213

Опубликована: Май 11, 2017

C–F/C–H functionalizations proved to be viable within a versatile manganese(I) catalysis manifold. Thus, wealth of fluorinated alkenes were employed in through facile C–H activation. The robust nature the regime was among others reflected by first activation with perfluoroalkenes as well racemization-free on imines, amino acids, and peptides.

Язык: Английский

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