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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Cobalt-Catalyzed C–H Activation

ACS Catalysis, Год журнала: 2015, Номер 6(2), С. 498 - 525

Опубликована: Ноя. 24, 2015

Catalytic C–H activation has emerged as a powerful tool for sustainable syntheses. In the recent years, notable success was achieved with development of cobalt-catalyzed functionalizations either in situ generated or single-component cobalt-complexes under mild reaction conditions. Herein, progress field organometallic is reviewed until November 2015.

Язык: Английский

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Transition-Metal-Catalyzed Cross-Couplings through Carbene Migratory Insertion

Chemical Reviews, Год журнала: 2017, Номер 117(23), С. 13810 - 13889

Опубликована: Ноя. 1, 2017

Transition-metal-catalyzed cross-coupling reactions have been well-established as indispensable tools in modern organic synthesis. One of the major research goals area is expanding scope coupling partners. In past decade, diazo compounds (or their precursors N-tosylhydrazones) emerged nucleophilic partners C-C single bond or C═C double formations transition-metal-catalyzed reactions. This type reaction involves following general steps. First, organometallic species generated by various processes, including oxidative addition, transmetalation, cyclization, cleavage, and C-H activation. Subsequently, reacts with substrate to generate metal carbene intermediate, which undergoes rapid migratory insertion form a bond. The new from may undergo transformations. carbene-based has proven be general: transition metals Pd, Cu, Rh, Ni, Co, Ir are effective catalysts; also extended substrates other than compounds; cascade processes devised based on insertion. review will summarize achievements made this field since 2001.

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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Cp*Co^III Catalyzed Site‐Selective CH Activation of Unsymmetrical O‐Acyl Oximes: Synthesis of Multisubstituted Isoquinolines from Terminal and Internal Alkynes

Angewandte Chemie International Edition, Год журнала: 2015, Номер 54(44), С. 12968 - 12972

Опубликована: Сен. 28, 2015

The synthesis of isoquinolines by site-selective C-H activation O-acyl oximes with a Cp*Co(III) catalyst is described. In the presence this catalyst, various unsymmetrically substituted selectively occurred at sterically less hindered site, and reactions terminal as well internal alkynes afforded corresponding products in up to 98 % yield. Whereas catalyzed system proceeded high site selectivity (15:1 20:1), use Cp*Rh(III) catalysts led low selectivities and/or yields when unsymmetrical were used. Deuterium labeling studies indicate clear difference step under catalysis.

Язык: Английский

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Dehydrative Direct CH Allylation with Allylic Alcohols under [Cp*Co^III] Catalysis

Angewandte Chemie International Edition, Год журнала: 2015, Номер 54(34), С. 9944 - 9947

Опубликована: Июль 1, 2015

Abstract The unique reactivity of [Cp*Co III ] over [Cp*Rh was demonstrated. A cationic catalyst promoted direct dehydrative CH allylation with non‐activated allyl alcohols, thus giving C2‐allylated indoles, pyrrole, and phenyl‐pyrazole in good yields, while analogous catalysts were not effective. high γ‐selectivity C2‐selectivity indicated that the reaction proceeded by directing‐group‐assisted metalation. DFT calculations suggested γ‐selective substitution metalation insertion a CC double bond, subsequent β‐hydroxide elimination. favored elimination β‐hydride

Язык: Английский

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High‐Valent‐Cobalt‐Catalyzed C−H Functionalization Based on Concerted Metalation–Deprotonation and Single‐Electron‐Transfer Mechanisms

ChemCatChem, Год журнала: 2016, Номер 8(7), С. 1242 - 1263

Опубликована: Март 23, 2016

Abstract C−H functionalization has been established as a powerful strategy for the commercial construction of organic molecules. This review encompasses most recent advances in activation catalyzed by earth‐abundant cobalt complexes, involving two types fundamental reaction paths, that is, concerted metalation–deprotonation (CMD) path associated with non‐oxidative and intermolecular single‐electron‐transfer (SET) path. Transformations high‐valent based on mechanisms used syntheses, including those C−C C−X (X=O N) bond formation, are herein presented.

Язык: Английский

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Cycloaddition reactions of enoldiazo compounds

Chemical Society Reviews, Год журнала: 2017, Номер 46(17), С. 5425 - 5443

Опубликована: Янв. 1, 2017

A comprehensive review on cycloaddition reactions of enoldiazo compounds is presented with emphasis methodology development and mechanistic insight.

Язык: Английский

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Cobalt-Catalyzed Cyclization of Aliphatic Amides and Terminal Alkynes with Silver-Cocatalyst

Journal of the American Chemical Society, Год журнала: 2015, Номер 137(40), С. 12990 - 12996

Опубликована: Сен. 21, 2015

A new method of cobalt-catalyzed synthesis pyrrolidinones from aliphatic amides and terminal alkynes was discovered through a C–H bond functionalization process on unactivated sp3 carbons with the silver cocatalyst using bidentate auxiliary. For first time, broad range easily accessible are exploited as reaction partner in C(sp3)–H activation to give important 5-ethylidene-pyrrolidin-2-ones site-selective fashion. The tolerates wide variety functional groups including −F, −Cl, −Br, −CF3, ether, cyclopropane, thiophene. Both pyridine ligand aromatic solvent play role for promotion reactivity. This cyclization can be successfully extended afford isoindolinones. Attractive features this catalytic system include its low cost, easy operation, convenient access

Язык: Английский

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