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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Transition metal-catalyzed C–H bond functionalizations by the use of diverse directing groups

Organic Chemistry Frontiers, Journal Year: 2015, Volume and Issue: 2(9), P. 1107 - 1295

Published: Jan. 1, 2015

In this review, a summary of transition metal-catalyzed C–H activation by utilizing the functionalities as directing groups is presented.

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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Transient Directing Groups for Transformative C–H Activation by Synergistic Metal Catalysis

Chem, Journal Year: 2017, Volume and Issue: 4(2), P. 199 - 222

Published: Dec. 21, 2017

Language: Английский

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A Simple and Versatile Amide Directing Group for C−H Functionalizations

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 55(36), P. 10578 - 10599

Published: Aug. 1, 2016

Abstract Achieving selective C−H activation at a single and strategic site in the presence of multiple bonds can provide powerful generally useful retrosynthetic disconnection. In this context, directing group serves as compass to guide transition metal by using distance geometry recognition parameters distinguish between proximal distal bonds. However, installation removal groups is practical drawback. To improve utility approach, one seek solutions three directions: 1) Simplifying group, 2) common functional or protecting groups, 3) attaching substrates via transient covalent bond render catalytic. This Review describes rational development an extremely simple yet broadly applicable for Pd II , Rh III Ru catalysts, namely N‐methoxy amide (CONHOMe) moiety. Through collective efforts community, wide range transformations type have been developed.

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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Transition metal-catalyzed C–H functionalization of N-oxyenamine internal oxidants

Chemical Society Reviews, Journal Year: 2014, Volume and Issue: 44(5), P. 1155 - 1171

Published: Nov. 24, 2014

The N-oxyenamine internal oxidant gives more chance to investigate the C–H bond activation under mild reaction conditions.

Language: Английский

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Metalla-electrocatalyzed C–H Activation by Earth-Abundant 3d Metals and Beyond

Accounts of Chemical Research, Journal Year: 2019, Volume and Issue: 53(1), P. 84 - 104

Published: Dec. 19, 2019

To improve the efficacy of molecular syntheses, researchers wish to capitalize upon selective modification otherwise inert C-H bonds. The past two decades have witnessed considerable advances in coordination chemistry that set stage for transformative tools functionalizations. Particularly, oxidative C-H/C-H and C-H/Het-H transformations gained major attention because they avoid all elements substrate prefunctionalization. Despite advances, activations been dominated by precious transition metal catalysts based on palladium, ruthenium, iridium, rhodium, thus compromising sustainable nature overall activation approach. same holds true predominant use stoichiometric chemical oxidants regeneration active catalyst, prominently featuring hypervalent iodine(III), copper(II), silver(I) oxidants. Thereby, quantities undesired byproducts are generated, which preventive applications scale. In contrast, elegant merger homogeneous metal-catalyzed with electrosynthesis bears unique power achieve outstanding levels oxidant resource economy. Thus, contrast classical electrosyntheses control, metalla-electrocatalysis huge largely untapped potential unmet site selectivities means catalyst control. While indirect electrolysis using palladium complexes has realized, less toxic expensive base feature distinct beneficial assets toward this Account, I summarize emergence electrocatalyzed earth-abundant 3d metals beyond, a topical focus contributions from our laboratories through November 2019. cobalt electrocatalysis was identified as particularly powerful platform wealth transformations, including oxygenations nitrogenations well alkynes, alkenes, allenes, isocyanides, carbon monoxide, among others. As complementary tools, nickel, copper, very recently iron devised metalla-electrocatalyzed activations. Key success were detailed mechanistic insights, oxidation-induced reductive elimination scenarios. Likewise, development methods make weak O-coordination benefited crucial insights into catalyst's modes action experiment, operando spectroscopy, computation. Overall, thereby syntheses These electrooxidative frequently characterized improved chemoselectivities. Hence, ability dial redox at minimum level required desired transformation renders an ideal functionalization structurally complex molecules sensitive functional groups. This strategy was, inter alia, successfully applied scale-up continuous flow step-economical assembly polycyclic aromatic hydrocarbons.

Language: Английский

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