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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Photoredox Catalysis for Building C–C Bonds from C(sp²)–H Bonds

Chemical Reviews, Год журнала: 2018, Номер 118(16), С. 7532 - 7585

Опубликована: Июль 16, 2018

Transition metal-catalyzed C–H bond functionalizations have been the focus of intensive research over last decades for formation C–C bonds from unfunctionalized arenes, heteroarenes, alkenes. These direct transformations provide new approaches in synthesis with high atom- and step-economy compared to traditional catalytic cross-coupling reactions. However, such methods still suffer several limitations including functional group tolerance lack regioselectivity. In addition, they often require harsh reaction conditions some them need use strong oxidant, a stoichiometric amount, avoiding these processes be truly eco-friendly. The photoredox catalysis has contributed significant expansion scope C(sp2)–H which include arylations, (perfluoro)alkylations, acylations, even cyanations. Most involve photochemical induced generation radical followed by its regioselective addition or alkenes, leading building C(sp2)–C bond. plays crucial roles reactions promoting electron transfer, enabling species single either oxidation reduction. Such operating at room temperature allow chemo-, regio-, stereoselectivity. This review surveys initiated involves functionalization step, describes advantages functionalizations, presents mechanistic insights into role played catalysts.

Язык: Английский

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Organocatalysis in Inert C–H Bond Functionalization

Chemical Reviews, Год журнала: 2017, Номер 117(13), С. 9433 - 9520

Опубликована: Фев. 13, 2017

As two coexisting and fast-growing research fields in modern synthetic chemistry, the merging of organocatalysis C–H bond functionalization is well foreseeable, joint force along this line has been demonstrated to be a powerful approach making inert more viable, predictable, selective. In review, we provide comprehensive summary over past decades. The review arranged by types bonds including alkane C–H, arene vinyl as those activated benzylic allylic alpha heteroatom such nitrogen oxygen. each section, discussion classified explicit organocatalytic mode involved.

Язык: Английский

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Photocatalytic decarboxylative alkylations mediated by triphenylphosphine and sodium iodide

Science, Год журнала: 2019, Номер 363(6434), С. 1429 - 1434

Опубликована: Март 28, 2019

Most photoredox catalysts in current use are precious metal complexes or synthetically elaborate organic dyes, the cost of which can impede their application for large-scale industrial processes. We found that a combination triphenylphosphine and sodium iodide under 456-nanometer irradiation by blue light-emitting diodes catalyze alkylation silyl enol ethers decarboxylative coupling with redox-active esters absence transition metals. Deaminative using Katritzky's N-alkylpyridinium salts trifluoromethylation Togni's reagent also demonstrated. Moreover, phosphine/iodide-based system catalyzes Minisci-type N-heterocycles operate tandem chiral phosphoric acids to achieve high enantioselectivity this reaction.

Язык: Английский

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Photoredox-Catalyzed C–H Functionalization Reactions

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 1925 - 2016

Опубликована: Сен. 29, 2021

The fields of C–H functionalization and photoredox catalysis have garnered enormous interest utility in the past several decades. Many different scientific disciplines relied on strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, fine chemical synthesis. In this Review, we highlight use reactions. We separate review into inorganic/organometallic catalysts organic-based catalytic systems. Further subdivision by reaction class─either sp2 or sp3 functionalization─lends perspective tactical for these methods synthetic applications.

Язык: Английский

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Iron Catalysis in Organic Synthesis: A Critical Assessment of What It Takes To Make This Base Metal a Multitasking Champion

ACS Central Science, Год журнала: 2016, Номер 2(11), С. 778 - 789

Опубликована: Окт. 27, 2016

The current status of homogeneous iron catalysis in organic chemistry is contemplated, as are the reasons why this particular research area only recently starts challenging enduring dominance late and mostly noble metals over field. Centered middle d-block able to support formal oxidation states ranging from -II +VI, catalysts hold promise being encompass synthesis at large. They expected serve reductive well oxidative regimes, can emulate "noble tasks", but also adopt "early" transition metal character. Since a comprehensive coverage multidimensional agenda beyond scope an Outlook anyway, emphasis laid article on analysis factors that perhaps allow one control multifarious chemical nature earth-abundant metal. challenges significant, not least analytical frontier; their mastery mandates mindset differs routines most chemists interested (noble metal) tend cultivate. This aspect notwithstanding, it safe predict bears chance enable responsible paradigm for sustained catalyst economy, while potentially providing substantial economic advantages. will spur systematic in-depth investigations takes upgrade strategy-level beyond.

Язык: Английский

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Recent Advances in Minisci‐Type Reactions

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(39), С. 13666 - 13699

Опубликована: Март 20, 2019

Abstract Reactions that involve the addition of carbon‐centered radicals to basic heteroarenes, followed by formal hydrogen atom loss, have become widely known as Minisci‐type reactions. First developed into a useful synthetic tool in late 1960s Minisci, this reaction type has been constant use over last half century chemists seeking functionalize heterocycles rapid and direct manner, avoiding need for de novo heterocycle synthesis. Whilst originally protocols radical generation remain active today, they joined recent years new array strategies allow wider variety precursors often operate under milder more benign conditions. The surge interest transformations based on free reactivity meant numerous choices are now available chemist looking utilize reaction. Radical‐generation methods photoredox catalysis electrochemistry approaches which thermal cleavage or situ reactive precursors. This review will cover remarkably large body literature appeared topic decade an attempt provide guidance chemist, well perspective both challenges overcome those still remain. As logical classification advances nature precursor, with most concerned, control various selectivity aspects associated reactions also be discussed.

Язык: Английский

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Recent advances in copper-catalysed radical-involved asymmetric 1,2-difunctionalization of alkenes

Chemical Society Reviews, Год журнала: 2019, Номер 49(1), С. 32 - 48

Опубликована: Дек. 5, 2019

The radical-involved 1,2-difunctionalization of alkenes has developed into a robust tool for preparation complex organic molecules. Despite significant advances in this area, the catalytic asymmetric version still remains challenging task mainly due to difficulty stereocontrol highly reactive radical intermediates. Recently, owing good single-electron transfer ability and coordination with chiral ligands copper catalysts, remarkable achievements alkene difunctionalization have been made via synergistic combination ligands. This tutorial review highlights recent progress copper-catalysed mechanistic scenarios governing stereocontrol, an emphasis on utilization

Язык: Английский

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Transition‐Metal‐Catalyzed Carboxylation Reactions with Carbon Dioxide

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(49), С. 15948 - 15982

Опубликована: Май 3, 2018

Driven by the inherent synthetic potential of CO2 as an abundant, inexpensive and renewable C1 chemical feedstock, recent years have witnessed renewed interest in devising catalytic fixations into organic matter. Although formation C-C bonds via fixation remained rather limited for a long period time, close look literature data indicates that carboxylation reactions entered new era exponential growth, evolving mature discipline allows streamlining synthesis carboxylic acids, building blocks utmost relevance industrial endeavors. These strategies generally proven broadly applicability convenient to perform. However, substantial challenges still need be addressed reinforcing cover metal-catalyzed area conceptual concise manner, delineating underlying principles are slowly emerging this vibrant expertise.

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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