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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Electrochemical strategies for C–H functionalization and C–N bond formation

Chemical Society Reviews, Journal Year: 2018, Volume and Issue: 47(15), P. 5786 - 5865

Published: Jan. 1, 2018

This review provides an overview of the use electrochemistry as appealing platform for expediting carbon–hydrogen functionalization and carbon–nitrogen bond formation.

Language: Английский

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New Strategies for the Transition-Metal Catalyzed Synthesis of Aliphatic Amines

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(5), P. 2613 - 2692

Published: Feb. 17, 2020

Transition-metal catalyzed reactions that are able to construct complex aliphatic amines from simple, readily available feedstocks have become a cornerstone of modern synthetic organic chemistry. In light the ever-increasing importance across range chemical sciences, this review aims provide concise overview transition-metal approaches alkylamine synthesis and their functionalization. Selected examples amine bond forming include: (a) hydroamination hydroaminoalkylation, (b) C(sp3)–H functionalization, (c) visible-light-mediated photoredox catalysis.

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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Organic Electrochemistry: Molecular Syntheses with Potential

ACS Central Science, Journal Year: 2021, Volume and Issue: 7(3), P. 415 - 431

Published: March 9, 2021

Efficient and selective molecular syntheses are paramount to

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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The Essential Role of Bond Energetics in C–H Activation/Functionalization

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(13), P. 8622 - 8648

Published: March 10, 2017

The most fundamental concepts in chemistry are structure, energetics, reactivity and their inter-relationships, which indispensable for promoting into a rational science. In this regard, bond energy, the intrinsic determinant directly related to structure reactivity, should be essential serving as quantitative basis design understanding of organic transformations. Although C-H activation/functionalization have drawn tremendous research attention flourished during past decades, governing rules energetics these processes is still fragmentary seems applicable only limited cases, such metal-oxo-mediated hydrogen atom abstraction. Despite complexity difficulties measuring energies both substrates intermediates, definitely very important issue that more generally contemplated. To end, review rooted energetic aspects activation/functionalization, were previously rarely discussed detail. Starting with concise but necessary introduction various classical methods heterolytic homolytic bonds, present provides examples applied concept values energy rationalizing observations associated and/or selectivity activation/functionalization.

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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Enantioselective C−H Activation with Earth‐Abundant 3d Transition Metals

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(37), P. 12803 - 12818

Published: May 11, 2019

Molecular syntheses largely rely on time- and labour-intensive prefunctionalization strategies. In contrast, C-H activation represents an increasingly powerful approach that avoids lengthy of prefunctionalized substrates, with great potential for drug discovery, the pharmaceutical industry, material sciences, crop protection, among others. The enantioselective functionalization omnipresent bonds has emerged as a transformative tool step- atom-economical generation chiral molecular complexity. However, this rapidly growing research area remains dominated by noble transition metals, prominently featuring toxic palladium, iridium rhodium catalysts. Indeed, despite significant achievements, use inexpensive sustainable 3d metals in asymmetric activations is still clearly its infancy. Herein, we discuss remarkable recent progress transformations via organometallic base up to April 2019.

Language: Английский

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Photochemical Generation of Nitrogen-Centered Amidyl, Hydrazonyl, and Imidyl Radicals: Methodology Developments and Catalytic Applications

ACS Catalysis, Journal Year: 2017, Volume and Issue: 7(8), P. 4999 - 5022

Published: June 19, 2017

During the past decade, visible light photocatalysis has become a powerful synthetic platform for promoting challenging bond constructions under mild reaction conditions. These photocatalytic systems rely on harnessing energy purposes through generation of reactive but controllable free radical species. Recent progress in area established it as an enabling catalytic strategy and selective nitrogen-centered radicals. The application activation amides, hydrazones, imides represents valuable approach facilitating formation Within span only couple years, significant been made expediting amidyl, hydrazonyl, imidyl radicals from variety precursors. This Perspective highlights recent advances light-mediated these A particular emphasis is placed unique ability accessing elusive manifolds construction diversely functionalized nitrogen-containing motifs nontraditional disconnections contemporary chemistry.

Language: Английский

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