A Perspective on Late-Stage Aromatic C–H Bond Functionalization

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(6), С. 2399 - 2414

Опубликована: Янв. 27, 2022

Late-stage functionalization of C-H bonds (C-H LSF) can provide a straightforward approach to the efficient synthesis functionalized complex molecules. However, LSF is challenging because bond must be in presence various other functional groups. In this Perspective, we evaluate aromatic on basis four criteria─reactivity, chemoselectivity, site-selectivity, and substrate scope─and our own views current challenges as well promising strategies areas growth going forward.

Язык: Английский

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Copper-catalyzed radical relay in C(sp³)–H functionalization

Chemical Society Reviews, Год журнала: 2022, Номер 51(5), С. 1640 - 1658

Опубликована: Янв. 1, 2022

Radical-involved transition metal (TM) catalysis has greatly enabled new reactivities in recent decades. Copper-catalyzed radical relay offers enormous potential C(sp3)-H functionalization which combines the unique regioselectivity of hydrogen atom transfer (HAT) and versatility copper-catalyzed cross-coupling. More importantly, significant progress been achieved asymmetric C-H through judicious ligand design. This tutorial review will highlight advances this rapidly growing area, we hope survey inspire future strategic developments for selective functionalization.

Язык: Английский

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Supramolecular Coordination Cages for Artificial Photosynthesis and Synthetic Photocatalysis

Chemical Reviews, Год журнала: 2023, Номер 123(9), С. 5225 - 5261

Опубликована: Янв. 20, 2023

Because sunlight is the most abundant energy source on earth, it has huge potential for practical applications ranging from sustainable supply to light driven chemistry. From a chemical perspective, excited states generated by make thermodynamically uphill reactions possible, which forms basis storage into fuels. In addition, with light, open-shell species can be open up new reaction pathways in organic synthesis. Crucial are photosensitizers, absorb and transfer substrates various mechanisms, processes that highly depend distance between molecules involved. Supramolecular coordination cages well studied synthetically accessible vessels single cavities guest binding, ensuring close proximity of different components. Due high modularity their size, shape, nature metal centers ligands, ideal platforms exploit preorganization photocatalysis. Herein we focus application supramolecular photocatalysis artificial photosynthesis photo(redox) catalysis. Finally, brief overview immobilization strategies provides tools implementing devices. This review inspiration future design photocatalytic host-guest systems producing solar fuels complex molecules.

Язык: Английский

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Photobiocatalytic Strategies for Organic Synthesis

Chemical Reviews, Год журнала: 2023, Номер 123(9), С. 5459 - 5520

Опубликована: Апрель 28, 2023

Biocatalysis has revolutionized chemical synthesis, providing sustainable methods for preparing various organic molecules. In enzyme-mediated most reactions involve molecules operating from their ground states. Over the past 25 years, there been an increased interest in enzymatic processes that utilize electronically excited states accessed through photoexcitation. These photobiocatalytic a diverse array of reaction mechanisms are complementary to one another. This comprehensive review will describe state-of-the-art strategies photobiocatalysis synthesis until December 2022. Apart reviewing relevant literature, central goal this is delineate mechanistic differences between general employed field. We organize based on relationship photochemical step and transformations. The include studies, substrate scopes, protein optimization strategies. By clearly defining mechanistically-distinct chemistry, we hope illuminate future synthetic opportunities area.

Язык: Английский

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Ferrocene-Mediated Photocatalytic Annulation of N-Sulfonyl Ketimines on a Polycrystalline WSe₂ Semiconductor Photocatalyst

ACS Catalysis, Год журнала: 2023, Номер 13(19), С. 13071 - 13076

Опубликована: Сен. 22, 2023

A merger of heterogeneous polycrystalline WSe2 semiconductor photocatalysis and homogeneous ferrocene redox catalysis for the cascade radical coupling-annulation reactions was established. In redox-mediated photocatalysis, can improve separation photogenerated hole–electron pairs on by consuming hole via formation a cation, which triggered molecular transformations. Various benzo[e]imidazo[1,5-c][1,2,3]oxathiazine 5,5-dioxides were formed through semiheterogeneous three-component reaction N-sulfonyl ketimines, N-arylglycines, formaldehyde.

Язык: Английский

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Dearomative ring expansion of thiophenes by bicyclobutane insertion

Science, Год журнала: 2023, Номер 381(6653), С. 75 - 81

Опубликована: Июль 6, 2023

Skeletal ring enlargement is gaining renewed interest in synthetic chemistry and has recently focused on insertion of one or two atoms. Strategies for heterocyclic expansion through small-ring remain elusive, although they would lead to the efficient formation bicyclic products. Here, we report a photoinduced dearomative thiophenes by bicyclo[1.1.0]butanes produce eight-membered rings under mild conditions. The value, broad functional-group compatibility, excellent chemo- regioselectivity were demonstrated scope evaluation product derivatization. Experimental computational studies point toward photoredox-induced radical pathway.

Язык: Английский

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Semi-heterogeneous g-C₃N₄/NaI dual catalytic C–C bond formation under visible light

Green Chemistry, Год журнала: 2023, Номер 25(8), С. 3292 - 3296

Опубликована: Янв. 1, 2023

The semi-heterogeneous g-C 3 N 4 /NaI dual catalytic system driven C–C bond formation between quinoxalin-2(1 H )-ones and arylhydrazines under blue light irradiation is reported for the first time.

Язык: Английский

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Reticular framework materials for photocatalytic organic reactions

Chemical Society Reviews, Год журнала: 2023, Номер 52(22), С. 7949 - 8004

Опубликована: Янв. 1, 2023

Photocatalytic organic reactions, harvesting solar energy to produce high value-added chemicals, have attracted increasing attention as a sustainable approach address the global crisis and environmental issues. Reticular framework materials, including metal-organic frameworks (MOFs) covalent (COFs), are widely considered promising candidates for photocatalysis owing their crystallinity, tailorable pore environment extensive structural diversity. Although design synthesis of MOFs COFs been intensively developed in last 20 years, applications photocatalytic transformations still preliminary stage, making systematic summary necessary. Thus, this review aims provide comprehensive understanding useful guidelines exploration suitable MOF COF photocatalysts towards appropriate reactions. The commonly used reactions categorized facilitate identification reaction types. From practical viewpoint, fundamentals experimental design, active species, performance evaluation external conditions, discussed detail easy experimentation. Furthermore, latest advances COFs, composites, comprehensively summarized according actual sites, together with discussion structure-property relationship. We believe that study will be helpful researchers novel reticular various synthetic applications.

Язык: Английский

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N-Functionalized Pyridinium Salts: A New Chapter for Site-Selective Pyridine C–H Functionalization via Radical-Based Processes under Visible Light Irradiation

Accounts of Chemical Research, Год журнала: 2022, Номер 55(20), С. 3043 - 3056

Опубликована: Сен. 27, 2022

ConspectusThe radical-mediated C–H functionalization of pyridines has attracted considerable attention as a powerful tool in synthetic chemistry for the direct bonds pyridine scaffold. Classically, methods functionalized often involve Minisci-type reactions under strongly acidic conditions. However, site-selective unbiased systems been long-standing challenge because scaffold contains multiple competing reaction sites (C2 vs C4) to intercept free radicals. Therefore, prefunctionalization is required avoid issues observed with formation mixture regioisomers and overalkylated side products.Recently, N-functionalized pyridinium salts have attracting organic promising radical precursors surrogates. The notable advantage lies their ability enhance reactivity selectivity synthetically useful acid-free This approach enables exquisite regiocontrol nonclassical at C2 C4 positions mild conditions, which are suitable late-stage bioactive molecules greater complexity diversity. Over past five years, variety fascinating applications developed using various types visible light In addition, new platform alkene difunctionalization appropriately designed N-substituted bifunctional reagents reported, offering an innovative assembly process complex architectures. Intriguingly, strategies involving light-absorbing electron donor–acceptor (EDA) complexes between electron-rich donors further open up photocatalyst-free Furthermore, we enantioselective afford enantioenriched bearing through single-electron N-heterocyclic carbene (NHC) catalysis.Herein, provide broad overview our recent contributions development summarize cornerstones that successfully employ these major advances field systematically categorized on basis pyridines' N-substituent, N–X (X = O, N, C, SO2CF3), its patterns. identification activation modes mechanistic aspects discussed by providing representative each paradigm. We hope this Account will inspire interest continued innovation exploration transformations.

Язык: Английский

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Modular Access to Chiral α-(Hetero)aryl Amines via Ni/Photoredox-Catalyzed Enantioselective Cross-Coupling

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(19), С. 8797 - 8806

Опубликована: Май 3, 2022

Chiral α-aryl N-heterocycles are commonly found in natural products, pharmaceutical agents, and chiral catalysts but remain challenging to access via asymmetric catalysis. Herein, we report a general modular approach for the direct enantioselective α-arylation of saturated azacycles acyclic N-alkyl benzamides nickel/photoredox dual This process exploits hydrogen atom transfer ability photoeliminated chlorine radicals convert corresponding α-amino alkyl that then coupled with ubiquitous inexpensive (hetero)aryl chlorides. These coupling reactions require no oxidants or organometallic reagents, feature feedstock starting materials, broad substrate scope, high enantioselectivities, applicable late-stage diversification medicinally relevant complex molecules. Mechanistic studies suggest nickel catalyst uncommonly plays multiple roles, accomplishing radical generation, capture, cross-coupling, induction.

Язык: Английский

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