A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

Chemical Society Reviews, Journal Year: 2018, Volume and Issue: 47(17), P. 6603 - 6743

Published: Jan. 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.

Language: Английский

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Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2752 - 2906

Published: Aug. 10, 2021

Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing plethora opportunities to synthetic organic chemists. However, performing photochemical transformation can be quite challenge because various issues related the delivery photons. These challenges barred widespread adoption steps industry. past decade, several technological innovations led more reproducible, selective, and scalable photoinduced reactions. Herein, we provide comprehensive overview these exciting advances, including flow chemistry, high-throughput experimentation, reactor design scale-up, combination photo- electro-chemistry.

Language: Английский

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N‐(Acyloxy)phthalimides as Redox‐Active Esters in Cross‐Coupling Reactions

Advanced Synthesis & Catalysis, Journal Year: 2018, Volume and Issue: 360(9), P. 1735 - 1753

Published: Feb. 7, 2018

Abstract Recent years have witnessed a resurgence of novel, efficient and practical protocols for radical‐mediated cross‐coupling reactions involving N ‐(acyloxy)phthalimides (NHPI esters) as redox‐active esters. After the initial discovery properties NHPI esters, exciting examples SET‐based under thermal or photolytic conditions leading to diverse C–X (X=C, B, Si, Se, S) bonds been published. The operational simplicity broad applicability exhibited in ester‐based cross‐couplings bode well their widespread adoption. review presented herein covers all recent developments field ester (RAE)‐based since discovery. Depending on employed categorized into photoinduced non‐photoinduced with representative insightful mechanistic discussions. magnified image

Language: Английский

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Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2017 - 2291

Published: Nov. 23, 2021

We present here a review of the photochemical and electrochemical applications multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms which both an proton exchanged together, often concerted elementary step. As such, MS-PCET can function as non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from wide variety common functional groups. introduction practitioner’s guide reaction design, with emphasis on unique energetic selectivity features that characteristic this class. then chapters oxidative N–H, O–H, S–H, C–H homolysis methods, generation corresponding neutral species. Then, reductive PCET activations involving carbonyl, imine, other X═Y π-systems, heteroarenes, where ketyl, α-amino, heteroarene-derived radicals be generated. Finally, we asymmetric catalysis materials device applications. Within each chapter, subdivide by group undergoing homolysis, thereafter type transformation being promoted. Methods published prior end December 2020 presented.

Language: Английский

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Transition Metal-Catalyzed Organic Reactions under Visible Light: Recent Developments and Future Perspectives

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(16), P. 9170 - 9196

Published: July 20, 2020

The development of transition metal (TM) catalysis for organic synthesis under visible light without recourse to typical photoredox catalysts has become a rapidly growing area research and been actively explored in the past several years. Distinct from extensively developed catalysis, which photocatalyst generally does not directly participate bond-forming process, photocatalyst/TM synergistic absorbs photon energy transfers TM catalyst through redox or transfer this Review focuses on summarizing recent developments photocatalytic reactions that use complexes both absorb catalytic bond formation involving covalently bonded intermediate. contents are categorized by used (Pd, Cu, Co, Ni, Mn, Au, Rh, Fe, Ru), with descending sequence according number examples reported each metal, provide an overview April 2020. Future perspectives personal opinions regarding expanding field also discussed.

Language: Английский

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Radical Carboxylative Cyclizations and Carboxylations with CO₂

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(10), P. 2518 - 2531

Published: May 6, 2021

ConspectusCarbon dioxide (CO2) is not only a greenhouse gas and common waste product but also an inexpensive, readily available, renewable carbon resource. It important one-carbon (C1) building block in organic synthesis for the construction of valuable compounds. However, its utilization challenging owing to thermodynamic stability kinetic inertness. Although significant progress has been achieved, many limitations remain this field with regard substrate scope, reaction system, activation strategies.Since 2015, our group focused on CO2 synthesis. We are interested vast possibilities radical chemistry, although high reactivity radicals presents challenges controlling selectivity. hope develop highly useful transformations involving by achieving balance selectivity under mild conditions. Over past 6 years, we along other experts have disclosed radical-type carboxylative cyclizations carboxylations using CO2.We initiated research realizing Cu-catalyzed oxytrifluoromethylation allylamines heteroaryl methylamines generate 2-oxazolidones various precursors. Apart from Cu catalysis, visible-light photoredox catalysis powerful method achieve efficient cyclization. In these cases, single-electron-oxidation-promoted C–O bond formation between benzylic carbamates key step.Since carboxylic acids exist widely natural products bioactive drugs serve as bulk chemicals industry, realized further visible-light-promoted construct such chemicals. achieved selective umpolung imines, enamides, tetraalkylammonium salts, oxime esters successive single-electron-transfer (SSET) reduction. Using strategy, dearomative arylcarboxylation indoles CO2. addition incorporation 1 equiv per substrate, recently developed photoredox-catalyzed dicarboxylation alkenes, allenes, (hetero)arenes via SSET reduction, which allows two molecules into compounds diacids polymer precursors.In two-electron CO2, sought new strategies realize single-electron Inspired hypothetical electron-transfer mechanism iron–sulfur proteins, visible-light-driven thiocarboxylation alkenes catalytic iron salts promoters. The in-situ-generated Fe/S complexes likely able reduce anion, could react give stabilized radical. Moreover, charge-transfer complex (CTC) thiolate acrylate/styrene hydrocarboxylation generation or alkene anion. On basis novel CTC, organocatalytic Hantzsch ester effective reductant.

Language: Английский

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Single Electron Transfer-Induced Redox Processes Involving N-(Acyloxy)phthalimides

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(3), P. 1640 - 1683

Published: Jan. 20, 2021

The past decade has witnessed the emergence of N-(acyloxy)phthalimides (NHPI esters) and its derivatives at forefront synthetic methods facilitating construction diverse molecular frameworks from readily available carboxylic acid feedstock. NHPI esters are predisposed to undergo reductive fragmentation via a single electron transfer (SET) process under thermal, photochemical, or electrochemical conditions generate corresponding carbon- nitrogen-centered radicals that participate in multitude transformations forge carbon–carbon carbon–heteroatom bonds. chemistry involving received broad applicability not only well-designed cascade annulations but also medicinal natural product synthesis. This comprehensive Review, broadly categorized according nature bond formation, details progress made this field since initial discovery by providing representative examples with mechanistic details, an emphasis on challenges future directions.

Language: Английский

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Enantioselective Radical Reactions Using Chiral Catalysts

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(6), P. 5842 - 5976

Published: Jan. 24, 2022

Benefiting from the impressive increase in fundamental knowledge, last 20 years have shown a continuous burst of new ideas and consequently plethora catalytic methods for enantioselective radical reactions. This review aims to provide complete survey progress achieved over this latter period. The first part focuses on use chiral organocatalysts, these include catalysts covalently linked substrate those that interact with by weaker interactions like hydrogen bonds. second is devoted transition-metal redox catalysis which organized according increasing atomic number first-row transition metals (Ti, Cr, Fe, Mn, Co, Ni, Cu). Bioinspired manganese- iron-mediated hydroxylations oxidations are also discussed. A specific section dedicated reactivity Ru, Rh, Ir complexes as Lewis acids special focus at metal. Absorption photons result different events such energy transfer, single-electron hydrogen-atom transfer facilitating formation radicals. Organocatalysis has been successfully combined photocatalysts, opened pathways enlarging precursors available. merger photocatalysis organo- or metalla-photocatalysis brought novelty allowed discovery large original transformations. enzyme-catalyzed reactions involving intermediates largely benefit visible-light irradiation included review. provides comprehensive inventory goal detailing reaction mechanisms involved transformations any nonspecialist could find their own creativity invent yet unknown applications.

Language: Английский

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Ligand‐to‐Metal Charge Transfer (LMCT) Photochemistry at 3d‐Metal Complexes: An Emerging Tool for Sustainable Organic Synthesis

ChemCatChem, Journal Year: 2022, Volume and Issue: 14(19)

Published: Aug. 11, 2022

Abstract Despite the rich photochemistry of 3d‐metal complexes, utilization excited‐state reactivity these compounds in organic synthesis has been historically overlooked. The advent photoredox catalysis changed perception synthetic chemists towards photochemistry, and nowadays potential photoinduced, outer‐sphere single‐electron transfer events is widely recognized. More recently, an emerging new mode photoactivation taken spotlight, based on inner‐sphere triggered by population ligand‐to‐metal charge‐transfer (LMCT) excited states. Contrarily to photoredox, LMCT‐activation does not rely matching redox potentials, offers unique profiles particularly well suited Earth‐abundant metal complexes. Those appealing features are propelling development methods using this blueprint generate highly reactive open‐shell species under mild conditions. aim contribution provide a didactical tool for comprehension concept facilitate methodologies achieve sustainable chemical transformations.

Language: Английский

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Visible‐Light‐Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(31), P. 10514 - 10520

Published: June 4, 2019

Abstract Despite significant progress in aliphatic decarboxylation, an efficient and general protocol for radical aromatic decarboxylation has lagged far behind. Herein, we describe a strategy rapid access to both aryl alkyl radicals by photosensitized of the corresponding carboxylic acids esters followed their successive use divergent carbon–heteroatom carbon–carbon bond‐forming reactions. Identification suitable activator is key bypass competing single‐electron‐transfer mechanism “switch on” energy‐transfer‐mediated homolysis unsymmetrical σ‐bonds concerted fragmentation/decarboxylation process.

Language: Английский

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