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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Site-Selective C–H Functionalization via Synergistic Use of Electrochemistry and Transition Metal Catalysis

Accounts of Chemical Research, Год журнала: 2020, Номер 53(2), С. 300 - 310

Опубликована: Янв. 15, 2020

Electrochemical synthesis of organic compounds has emerged as an attractive and environmentally benign alternative to conventional approaches for oxidation reduction that utilizes electric current instead chemical oxidants reductants. As such, many useful transformations have been developed, including the Kolbe reaction, Simons fluorination process, Monsanto adiponitrile Shono oxidation, name a few. C-H functionalization represents one most promising reaction types among electrochemical transformations, since this process avoids prefunctionalization substrates provides novel retrosynthetic disconnections. However, site-selective anodic bonds is still fundamental challenge due high potentials compared solvents common functional groups. To overcome issue, indirect electrolysis via action mediator (a redox catalyst) regularly employed, by which selectivity can be controlled following said with substrate. Since transition metal complexes easily tuned modification ligand, synergistic use electrochemistry catalysis achieve strategy. In Account, we summarize contextualize our recent efforts toward metal-catalyzed proximal suitable directing group. We developed oxygenation, acylation, alkylation, halogenation reactions in Pd(II) species oxidized Pd(III) or Pd(IV) intermediate followed reductive elimination form corresponding C-O, C-C, C-X bonds. Importantly, improved monofunctionalization achieved Pd-catalyzed C(sp3)-H oxygenation using PhI(OAc)2 oxidant. Physical separators are sometimes used prevent deposition Pd black on cathode resulting from valent species. skirted issue through development Cu-catalyzed C(sp2)-H amination n-Bu4NI cocatalyst undivided cell. addition, Ir-catalyzed vinylic acrylic acids alkynes cell, affording various substituted α-pyrones good excellent yield. More importantly, oxidants, Ag2CO3, Cu(OAc)2, PhI(OAc)2, resulted much lower yields absence electrical under otherwise identical conditions. elaborated below, progress area effective platform friendly sustainable selective transformations.

Язык: Английский

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Recent Advances in Ruthenium(II)‐Catalyzed C−H Bond Activation and Alkyne Annulation Reactions

Advanced Synthesis & Catalysis, Год журнала: 2018, Номер 361(4), С. 654 - 672

Опубликована: Авг. 20, 2018

Abstract In the last few decades, transition metal‐catalyzed activation of inert C−H bonds has led to a fundamental change in field synthetic chemistry. Most these reactions deal with simple functionalizations or additions. However, recent years have witnessed an increase bond and annulation reactions. These are appealing organic chemist as they afford highly valuable cyclic compounds rapid sustainable manner from readily available compounds. This review article attempts highlight advances ruthenium alkyne magnified image

Язык: Английский

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Weak-Coordination in C–H Bond Functionalizations Catalyzed by 3d Metals

ACS Catalysis, Год журнала: 2022, Номер 12(6), С. 3452 - 3506

Опубликована: Март 3, 2022

Transition-metal-catalyzed C–H bond functionalizations have had an enormous influence on organic synthesis in recent times. However, the use of low-abundance 4d and 5d metals is almost inevitable, they are high demand. This will be a cause concern, hence, it important to develop methods based 3d metals, which widely present Earth's crust. In this regard, metal catalysts or their precursors for catalysis, general, functionalizations, particular, has gained significant momentum The major development catalytic with been achieved predominantly strongly coordinating directing groups such as pyridyl, pyrimidinyl, pyrazolyl, 8-amino-quinolinyl groups. Thus, prefunctionalization substrates these necessary, contradicts step- atom-economy activation. commonly available functional aldehyde, ketone, carboxylic acid, amide, hydroxy, N-oxides loosely bind through weak-coordination. These weakly orient activate regioselectively without need preinstalled Although challenging, contemporary topic actively pursued by many researchers Through article, we provide comprehensive overview metal-catalyzed, coordinating, directing-group-enabled reported until March 2021.

Язык: Английский

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Cobalt‐Catalyzed Annulation Reactions via C−H Bond Activation

ChemCatChem, Год журнала: 2017, Номер 10(4), С. 683 - 705

Опубликована: Ноя. 1, 2017

Abstract Considerable research attention has been directed towards the use of first‐row transition metals in organic synthesis. The more abundant, and less expensive cobalt is considered to be an effective alternative for second third‐row noble metals, especially C−H bond functionalization reactions. In this Minireview, we will summarize features, recent achievements Co‐catalyzed directing group assisted activation/cyclization reactions their mechanistic insights.

Язык: Английский

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Thioamide‐Directed Cobalt(III)‐Catalyzed Selective Amidation of C(sp³)−H Bonds

Angewandte Chemie International Edition, Год журнала: 2017, Номер 56(52), С. 16550 - 16554

Опубликована: Окт. 28, 2017

A mild, oxidant-free, and selective Cp*CoIII -catalyzed amidation of thioamides with robust dioxazolone amidating agents via C(sp3 )-H bond activation to generate the desired amidated products is reported. The method efficient allows for C-H a wide range functionalized aryl-, heteroaryl-, alkyl-substituted dioxazolones under conditions. observed regioselectivity towards primary supported by computational studies cyclometalation proposed proceed means an external carboxylate-assisted concerted metalation/deprotonation mechanism. reported rare example use directing group other than commonly used pyridine quinolone classes functionalization first exploit thioamides.

Язык: Английский

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Electrochemistry-Enabled Ir-Catalyzed Vinylic C–H Functionalization

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(48), С. 18970 - 18976

Опубликована: Ноя. 12, 2019

Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C–H functionalization, yet this type transformation thus far mainly been limited to arene functionalization. Herein, we report the development electrochemical vinylic functionalization acrylic acids with alkynes. In reaction an iridium catalyst enables C–H/O–H alkyne annulation, affording α-pyrones good excellent yields in undivided cell. Preliminary mechanistic studies show that anodic oxidation is crucial releasing product regeneration Ir(III) intermediate from diene-Ir(I) complex, which coordinatively saturated, 18-electron complex. Importantly, common chemical oxidants such Ag(I) or Cu(II) did not give significant amounts desired absence electrical current under otherwise identical conditions.

Язык: Английский

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Recent advances using [Cp*Co(CO)I₂] catalysts as a powerful tool for C–H functionalisation

Dalton Transactions, Год журнала: 2017, Номер 46(30), С. 9721 - 9739

Опубликована: Янв. 1, 2017

This perspective highlights recent applications of Cp*Co^III catalysts in C–H functionalisation protocols, exemplifying both terminal couplings and heterocycle formation.

Язык: Английский

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Recent advances in cobalt-catalysed C–H functionalizations

Organic & Biomolecular Chemistry, Год журнала: 2019, Номер 17(48), С. 10119 - 10141

Опубликована: Янв. 1, 2019

Ready availability, low cost and toxicity of cobalt salts have redirected the attention researchers away from noble metals, such as Pd, Rh, Ir, towards Co in field C-H functionalization. In this context, examples Co-catalysed functionalization exponentially grown over last few decades. This present review focuses on most recent developments C(sp2)-H C(sp3)-H functionalizations. Included is also a comprehensive overview enantioselective transformations.

Язык: Английский

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