3d Transition Metals for C–H Activation

Chemical Reviews, Journal Year: 2018, Volume and Issue: 119(4), P. 2192 - 2452

Published: Nov. 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.

Language: Английский

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Mild metal-catalyzed C–H activation: examples and concepts

Chemical Society Reviews, Journal Year: 2016, Volume and Issue: 45(10), P. 2900 - 2936

Published: Jan. 1, 2016

C–H Activation reactions that proceed under mild conditions are more attractive for applications in complex molecule synthesis. Mild transformations reported since 2011 reviewed and the different concepts strategies have enabled their mildness discussed.

Language: Английский

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

Chemical Society Reviews, Journal Year: 2018, Volume and Issue: 47(17), P. 6603 - 6743

Published: Jan. 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.

Language: Английский

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New advances in nanographene chemistry

Chemical Society Reviews, Journal Year: 2015, Volume and Issue: 44(18), P. 6616 - 6643

Published: Jan. 1, 2015

Nanographenes, or extended polycyclic aromatic hydrocarbons, have been attracting renewed and more widespread attention since the first experimental demonstration of graphene in 2004. However, atomically precise fabrication nanographenes has thus far achieved only through synthetic organic chemistry. The synthesis quasi-zero-dimensional nanographenes, i.e. molecules, witnessed rapid developments over past few years, these can be summarized four categories: (1) non-conventional methods, (2) structures incorporating seven- eight-membered rings, (3) selective heteroatom doping, (4) direct edge functionalization. On other hand, one-dimensional extension molecules leads to formation nanoribbons (GNRs) with high aspect ratios. structurally well-defined GNRs by extending nanographene longitudinally polymeric systems. Access becomes possible solution-mediated surface-assisted cyclodehydrogenation, "graphitization," tailor-made polyphenylene precursors. In this review, we describe recent progress "bottom-up" chemical syntheses namely GNRs.

Language: Английский

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Recent Advances in Radical C–H Activation/Radical Cross-Coupling

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(13), P. 9016 - 9085

Published: June 22, 2017

Research and industrial interest in radical C-H activation/radical cross-coupling chemistry has continuously grown over the past few decades. These reactions offer fascinating unconventional approaches toward connecting molecular fragments with high atom- step-economy that are often complementary to traditional methods. Success this area of research was made possible through development photocatalysis first-row transition metal catalysis along use peroxides as initiators. This Review provides a brief concise overview current status latest methodologies using radicals or cations key intermediates produced via activation. includes addition, cascade cyclization, radical/radical cross-coupling, coupling M-R groups, nucleophiles (Nu).

Language: Английский

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Oxidative C–H/C–H Coupling Reactions between Two (Hetero)arenes

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(13), P. 8787 - 8863

Published: Jan. 13, 2017

Transition metal-mediated C-H bond activation and functionalization represent one of the most straightforward powerful tools in modern organic synthetic chemistry. Bi(hetero)aryls are privileged π-conjugated structural cores biologically active molecules, functional materials, ligands, intermediates. The oxidative C-H/C-H coupling reactions between two (hetero)arenes through 2-fold offer a valuable opportunity for rapid assembly diverse bi(hetero)aryls further exploitation their applications pharmaceutical material sciences. This review provides comprehensive overview fundamentals transition metal-mediated/catalyzed (hetero)arenes. substrate scope, limitation, reaction mechanism, regioselectivity, chemoselectivity, as well related control strategies these discussed. Additionally, established methods synthesis natural products new materials exemplified. In last section, short introduction on oxidant- or Lewis acid-mediated Ar-H/Ar-H is presented, considering that it very method construction biaryl units polycylic arenes.

Language: Английский

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Iron-Catalyzed C–H Bond Activation

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(13), P. 9086 - 9139

Published: April 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.

Language: Английский

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Electrocatalytic C–H Activation

ACS Catalysis, Journal Year: 2018, Volume and Issue: 8(8), P. 7086 - 7103

Published: June 18, 2018

C–H activation has emerged as a transformative tool in molecular synthesis, but until recently oxidative activations have largely involved the use of stoichiometric amounts expensive and toxic metal oxidants, compromising overall sustainable nature chemistry. In sharp contrast, electrochemical been identified more efficient strategy that exploits storable electricity place byproduct-generating chemical reagents. Thus, transition-metal catalysts were shown to enable versatile reactions manner. While palladium catalysis set stage for C(sp2)–H C(sp3)–H functionalizations by N-containing directing groups, rhodium ruthenium allowed weakly coordinating amides acids. contrast these precious 4d transition metals, recent year witnessed emergence cobalt oxygenations, nitrogenations, C–C-forming [4+2] alkyne annulations. Thereby, silver(I) oxidants was prevented, improving environmentally benign catalysis. Herein, we summarize major advances organometallic otherwise inert bonds electrocatalysis through May 2018.

Language: Английский

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Manganese-Catalyzed C–H Activation

ACS Catalysis, Journal Year: 2016, Volume and Issue: 6(6), P. 3743 - 3752

Published: April 27, 2016

Manganese is found in the active center of numerous enzymes that operate by an outer-sphere homolytic C–H cleavage. Thus, a plethora bioinspired radical-based functionalizations manganese catalysis have been devised during past decades. In contrast, organometallic activation means has emerged only recently as increasingly viable tool organic synthesis. These manganese(I)-catalyzed processes enabled variety with ample scope, which very set stage for substitutive functionalizations. The versatile largely operates isohypsic, thus redox-neutral, mode action through chelation assistance, and provided step-economical access to structurally divers compounds relevance inter alia bioorganic, agrochemical, medicinal chemistry well material sciences.

Language: Английский

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Metal‐Catalyzed Annulations through Activation and Cleavage of C−H Bonds

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 55(37), P. 11000 - 11019

Published: June 22, 2016

The exponential increase in the number of catalytic transformations that involve a metal-promoted activation hitherto considered inert C-H bonds is promoting fundamental change field synthetic chemistry. Although most reactions involving activations consist simple functionalizations or additions, recent years have witnessed an upsurge related can be formally as cycloaddition processes. These are particularly appealing from perspective because they allow conversion readily available substrates into highly valuable cyclic products rapid and sustainable manner. In many cases, these annulations formation metallacyclic intermediates resemble those proposed for standard metal-catalyzed cycloadditions unsaturated precursors.

Language: Английский

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