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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Toxicity of Metal Compounds: Knowledge and Myths

Organometallics, Journal Year: 2017, Volume and Issue: 36(21), P. 4071 - 4090

Published: Nov. 13, 2017

Organometallic reagents and metal catalysts are used ubiquitously in academia industry. Not surprisingly, the biological activity environmental danger of compounds have become topics outstanding importance. In spite rapid development toxicology during last decades, several common historically established "beliefs" still frequently circulating organometallic community. this Tutorial, we discuss existing opinions concerning (1) possibilities toxicity measurements, (2) high toxicities heavy-metal compounds, (3) correlation between structure a compound its toxicity, (4) effect direct/indirect contacts with (5) dangers nanoparticles. Basic concepts studies known data described Tutorial step by upon discussion these issues. The main goal is to demonstrate that cannot be regarded as constant property, since it depends on oxidation state, ligands, solubility, morphology particles, properties environment, other factors. As far such chemically labile species concerned, nature effects should not assumed or taken for granted; indeed, reliable conclusions made without dedicated measurements.

Language: Английский

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C–H activation

Nature Reviews Methods Primers, Journal Year: 2021, Volume and Issue: 1(1)

Published: June 17, 2021

Language: Английский

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A radical approach to the copper oxidative addition problem: Trifluoromethylation of bromoarenes

Science, Journal Year: 2018, Volume and Issue: 360(6392), P. 1010 - 1014

Published: June 1, 2018

Transition metal-catalyzed arene functionalization has been widely used for molecular synthesis over the past century. In this arena, copper catalysis long considered a privileged platform due to propensity of high-valent undergo reductive elimination with wide variety coupling fragments. However, sluggish nature oxidative addition limited copper's capacity broadly facilitate haloarene protocols. Here, we demonstrate that problem can be overcome an aryl radical-capture mechanism, wherein radical is generated through silyl halogen abstraction. This strategy was applied general trifluoromethylation bromides dual copper-photoredox catalysis. Mechanistic studies support formation open-shell species.

Language: Английский

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Development of Halogenase Enzymes for Use in Synthesis

Chemical Reviews, Journal Year: 2017, Volume and Issue: 118(1), P. 232 - 269

Published: May 3, 2017

Nature has evolved halogenase enzymes to regioselectively halogenate a diverse range of biosynthetic precursors, with the halogens introduced often having profound effect on biological activity resulting natural products. Synthetic endeavors create non-natural bioactive small molecules for pharmaceutical and agrochemical applications have also arrived at similar conclusion: can dramatically improve properties organic selective modulation targets in vivo. Consequently, high proportion pharmaceuticals agrochemicals market today possess halogens. Halogenated compounds are common intermediates synthesis particularly valuable metal-catalyzed cross-coupling reactions. Despite potential utility organohalogens, traditional nonenzymatic halogenation chemistry utilizes deleterious reagents lacks regiocontrol. Reliable, facile, cleaner methods regioselective therefore essential development economical environmentally friendly industrial processes. A avenue toward such is use enzymes, responsible biosynthesis halogenated products, as biocatalysts. This Review will discuss advances developing halogenases biocatalysis, untapped sources biocatalysts how further optimization these required achieve goal scale biohalogenation.

Language: Английский

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Diverse ortho-C(sp²)–H Functionalization of Benzaldehydes Using Transient Directing Groups

Journal of the American Chemical Society, Journal Year: 2016, Volume and Issue: 139(2), P. 888 - 896

Published: Dec. 25, 2016

Pd-catalyzed C–H functionalizations promoted by transient directing groups remain largely limited to arylation only. Herein, we report a diverse set of ortho-C(sp2)–H benzaldehyde substrates using the group strategy. Without installing any auxiliary group, Pd(II)-catalyzed arylation, chlorination, bromination, and Ir(III)-catalyzed amidation, could be achieved on substrates. The formed in situ via imine linkage can override other coordinating functional capable activation or catalyst poisoning, significantly expanding scope for metal-catalyzed functionalization benzaldehydes. utility this approach is demonstrated through multiple applications, including late-stage diversification drug analogue.

Language: Английский

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Metal-Involving Synthesis and Reactions of Oximes

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(21), P. 13039 - 13122

Published: Oct. 9, 2017

This review classifies and summarizes the past 10–15 years of advancements in field metal-involving (i.e., metal-mediated metal-catalyzed) reactions oximes. These are diverse nature have been employed for syntheses oxime-based metal complexes cage-compounds, oxime functionalizations, preparation new classes organic species, particular, a wide variety heterocyclic systems spanning small 3-membered ring to macroheterocycles. consideration gives general outlook reaction routes, mechanisms, driving forces underlines potential conversions species application various fields chemistry draws attention emerging putative targets.

Language: Английский

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An overview of late-stage functionalization in today’s drug discovery

Expert Opinion on Drug Discovery, Journal Year: 2019, Volume and Issue: 14(11), P. 1137 - 1149

Published: Aug. 14, 2019

Introduction: Late-stage functionalization (LSF) can introduce important chemical groups in the very last steps of synthesis. LSF has potential to speed up preparation novel entities and diverse libraries have a major impact on drug discovery. Functional group tolerance mild conditions allows access new molecules not easily accessible by conventional approaches without need for laborious de novo synthesis.Areas Covered: A historical overview late-stage its applicability discovery is provided. Pioneering methodologies that laid foundations field are briefly covered archetypal examples their application discussed. Novel reported past few years mainly stemming from recent renaissances photoredox catalysis radical chemistry reviewed considered.Expert opinion: It envisioned will improve efficiency efficacy There evidence widespread uptake medicinal community it expected continuing endeavors many academic laboratories pharmaceutical companies soon an development.

Language: Английский

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Dual Photoredox/Nickel‐Catalyzed Three‐Component Carbofunctionalization of Alkenes

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(35), P. 12286 - 12290

Published: June 26, 2019

Abstract The potential of merging photoredox and nickel catalysis to perform multicomponent alkene difunctionalizations under visible‐light irradiation is demonstrated here. Secondary tertiary alkyl groups, as well sulfonyl moieties can be added the terminal position double bond with simultaneous arylation internal carbon atom in a single step mild reaction conditions. process, devoid stoichiometric additives, benefits from use bench‐stable easy‐to‐handle reagents, operationally simple, tolerates wide variety functional groups.

Language: Английский

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Nickel-Catalyzed Cross-Electrophile Coupling of Aryl Chlorides with Primary Alkyl Chlorides

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(22), P. 9902 - 9907

Published: May 15, 2020

Alkyl chlorides and aryl are among the most abundant stable carbon electrophiles. Although their coupling with nucleophiles is well developed, cross-electrophile of alkyl has remained a challenge. We report here first general approach to this transformation. The key productive, selective cross-coupling use small amount iodide or bromide along recently reported ligand, pyridine-2,6-bis(N-cyanocarboxamidine) (PyBCamCN). scope reaction demonstrated 35 examples (63 ± 16% average yield), we show that Br– I– additives act as cocatalysts, generating low, steady-state concentration more-reactive bromide/iodide.

Language: Английский

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