Transition-Metal-Catalyzed Cross-Couplings through Carbene Migratory Insertion

Chemical Reviews, Год журнала: 2017, Номер 117(23), С. 13810 - 13889

Опубликована: Ноя. 1, 2017

Transition-metal-catalyzed cross-coupling reactions have been well-established as indispensable tools in modern organic synthesis. One of the major research goals area is expanding scope coupling partners. In past decade, diazo compounds (or their precursors N-tosylhydrazones) emerged nucleophilic partners C-C single bond or C═C double formations transition-metal-catalyzed reactions. This type reaction involves following general steps. First, organometallic species generated by various processes, including oxidative addition, transmetalation, cyclization, cleavage, and C-H activation. Subsequently, reacts with substrate to generate metal carbene intermediate, which undergoes rapid migratory insertion form a bond. The new from may undergo transformations. carbene-based has proven be general: transition metals Pd, Cu, Rh, Ni, Co, Ir are effective catalysts; also extended substrates other than compounds; cascade processes devised based on insertion. review will summarize achievements made this field since 2001.

Язык: Английский

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

Chemical Society Reviews, Год журнала: 2018, Номер 47(15), С. 5786 - 5865

Опубликована: Янв. 1, 2018

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

Язык: Английский

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Cooperative Coupling of Oxidative Organic Synthesis and Hydrogen Production over Semiconductor-Based Photocatalysts

Chemical Reviews, Год журнала: 2021, Номер 121(21), С. 13051 - 13085

Опубликована: Авг. 11, 2021

Merging hydrogen (H2) evolution with oxidative organic synthesis in a semiconductor-mediated photoredox reaction is extremely attractive because the clean H2 fuel and high-value chemicals can be coproduced under mild conditions using light as sole energy input. Following this dual-functional photocatalytic strategy, dreamlike pathway for constructing C–C/C–X (X = C, N, O, S) bonds from abundant readily available X–H bond-containing compounds concomitant release of fulfilled without need external chemical reagents, thus offering green fascinating synthetic strategy. In review, we begin by presenting concise overview on general background traditional production then focus fundamental principles cooperative coupling selective simultaneous utilization photoexcited electrons holes over semiconductor-based catalysts to meet economic sustainability goal. Thereafter, put dedicated emphasis recent key progress various transformations, including alcohol oxidation, methane conversion, amines coupling, cross-coupling, cyclic alkanes dehydrogenation, reforming lignocellulosic biomass, so on. Finally, remaining challenges future perspectives flourishing area have been critically discussed. It anticipated that review will provide enlightening guidance rational design such system, thereby stimulating development economical environmentally benign solar generation value-added fine chemicals.

Язык: Английский

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

Chemical Reviews, Год журнала: 2020, Номер 120(5), С. 2613 - 2692

Опубликована: Фев. 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.

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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Electrocatalytic C–H Activation

ACS Catalysis, Год журнала: 2018, Номер 8(8), С. 7086 - 7103

Опубликована: Июнь 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.

Язык: Английский

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Complementary Strategies for Directed C(sp³)−H Functionalization: A Comparison of Transition‐Metal‐Catalyzed Activation, Hydrogen Atom Transfer, and Carbene/Nitrene Transfer

Angewandte Chemie International Edition, Год журнала: 2017, Номер 57(1), С. 62 - 101

Опубликована: Дек. 5, 2017

Abstract The functionalization of C(sp 3 )−H bonds streamlines chemical synthesis by allowing the use simple molecules and providing novel synthetic disconnections. Intensive recent efforts in development new reactions based on C−H have led to its wider adoption across a range research areas. This Review discusses strengths weaknesses three main approaches: transition‐metal‐catalyzed activation, 1, n ‐hydrogen atom transfer, carbene/nitrene for directed unactivated bonds. For each strategy, scope, reactivity different bonds, position reacting relative directing group, stereochemical outcomes are illustrated with examples literature. aim this is provide guidance inspire future area.

Язык: Английский

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Organic Electrochemistry: Molecular Syntheses with Potential

ACS Central Science, Год журнала: 2021, Номер 7(3), С. 415 - 431

Опубликована: Март 9, 2021

Efficient and selective molecular syntheses are paramount to

Язык: Английский

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Recent applications of C–H functionalization in complex natural product synthesis

Chemical Society Reviews, Год журнала: 2018, Номер 47(23), С. 8925 - 8967

Опубликована: Янв. 1, 2018

In this review, recent examples featuring C-H functionalization in the synthesis of complex natural products are discussed. A focus is given to way which can influence logical process retrosynthesis, and review organized by type method functionalization.

Язык: Английский

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Recent Advances in C–H Functionalization Using Electrochemical Transition Metal Catalysis

ACS Catalysis, Год журнала: 2018, Номер 8(8), С. 7179 - 7189

Опубликована: Июнь 19, 2018

Electrochemical transition metal catalysis is a powerful strategy for organic synthesis because it obviates the use of stoichiometric chemical oxidants and reductants. C–H bond functionalization offers variety useful conversions simple ubiquitous molecules into diverse functional groups in single synthetic operation. This review summarizes recent progress merging electrochemistry with metal-catalyzed functionalization, specifically C–C, C–X (halogen), C–O, C–P, C–N formation.

Язык: Английский

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