Three-component enantioselective alkenylation of organophosphonates via nickel metallaphotoredox catalysis

Chem, Год журнала: 2022, Номер 9(1), С. 154 - 169

Опубликована: Окт. 14, 2022

Язык: Английский

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Selective Three-Component Reductive Alkylalkenylation of Unbiased Alkenes via Carbonyl-Directed Nickel Catalysis

ACS Catalysis, Год журнала: 2022, Номер 12(15), С. 9779 - 9789

Опубликована: Июль 27, 2022

A Ni-catalyzed enantioselective reductive three-component alkylalkenylation of β,γ-alkenyl ketones with cis-alkenyl iodides and fluoroalkyl in the presence Mn is reported. By leveraging five-membered nickellacycles stabilized by pendant ketone group chiral bis(oxazoline) (BiOx) ligand, this protocol allows efficient access to enantioenriched β-alkenyl from simple starting materials. diverse electronically unbiased alkenes beyond that enables regioselective construction two C(sp3)–C(sp3) C(sp3)–(sp2) bonds one single operation also demonstrated.

Язык: Английский

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Copper-Catalyzed Three-Component Photo-ATRA-Type Reaction for Asymmetric Intermolecular C–O Coupling

ACS Catalysis, Год журнала: 2022, Номер 12(17), С. 10925 - 10937

Опубликована: Авг. 22, 2022

Atom transfer radical addition (ATRA) reaction of alkenes has had a significant impact on the field difunctionalization alkenes. Particularly, in three-component photo-ATRA-type processes, rich chemical space and structural diversity could be achieved by smart combination redox-active precursors third coupling components (e.g., halides, C-, N-, O-nucleophiles) under mild conditions. However, inherent complicated mechanisms involving chain or outer-sphere SET incipient intermediates have led to dearth general catalytic methods for highly enantioselective variants, especially those regarding asymmetric intermolecular C–O bond formation. Here, we report visible-light-induced copper-catalyzed with oxime esters carboxylic acids. In this process, cross-coupling between sp3-hybridized carbon radicals acids was enabled formation an aryl π-bond-engaged [σ + π]-copper complex. This working hypothesis renders naphthyl extended conjugation suitable substrates allows good stereocontrol. exhibits broad substrate scope high functional group tolerance respect each component, giving desired products generally yields enantioselectivity (>70 examples; up 97% ee). Preliminary experimental computational studies are also performed gain insight into mechanism stereoregulatory elements. finding provides promising platform development other benzylic-type radical-based reactions.

Язык: Английский

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Recent Advances in the Functionalization of Terminal and Internal Alkynes

Asian Journal of Organic Chemistry, Год журнала: 2022, Номер 11(5)

Опубликована: Март 9, 2022

Abstract Alkynes are one of the most fundamental and diverse functional groups utilized in organic synthesis. Over past few years, development efficient synthetic methodologies for functionalization alkynes has been an active area research. A plethora alkyne reactions have reported literature to construct functionalized alkene scaffolds, which important building blocks many natural products, pharmaceuticals, key intermediates various transformations. In this review, we describe recent advances with emphasis on substrate scope, limitations, regioselectivity control applications these reactions. This review covers from 2016 2021.

Язык: Английский

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Nickel-Catalyzed Three-Component Alkylacylation of Alkenes Enabled by a Photoactive Electron Donor–Acceptor Complex

Organic Letters, Год журнала: 2022, Номер 24(22), С. 3938 - 3943

Опубликована: Май 23, 2022

An electron donor-acceptor complex-enabled, nickel-catalyzed three-component net-reductive 1,2-alkylacylation of alkenes is developed. This conjunctive reductive acyl cross-coupling process obviates the use an exogenous photocatalyst and a stoichiometric metal-based reductant, affording various synthetically useful 1,3-dicarbonyl compounds in good yields with broad substrate scope excellent functional group tolerance. Both alkyl electrophiles are derived from highly abundant readily accessible carboxylic acids, making catalytic 1,2-dicarbofunctionalization more general sustainable.

Язык: Английский

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Intermolecular Photocatalytic Chemo‐, Stereo‐ and Regioselective Thiol–Yne–Ene Coupling Reaction

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(17)

Опубликована: Фев. 11, 2022

The first example of an intermolecular thiol-yne-ene coupling reaction is reported for the one-pot construction C-S and C-C bonds. Thiol-yne-ene opens a new dimension in building molecular complexity to access densely functionalized products. employment Eosin Y/DBU/MeOH photocatalytic system suppresses hydrogen atom transfer (HAT) associative reductant upconversion (via three-electron σ-bond formation). Investigation mechanism by combining online ESI-UHRMS, EPR spectroscopy, isotope labeling, determination quantum yield, cyclic voltammetry, Stern-Volmer measurements computational modeling revealed unique photoredox cycle with four radical-involving stages. As result, previously unavailable products were obtained good yields high selectivity. They can serve as stable precursors synthesizing synthetically demanding activated 1,3-dienes.

Язык: Английский

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Nickel‐Catalyzed Cross‐Electrophile 1,2‐Silyl‐Arylation of 1,3‐Dienes with Chlorosilanes and Aryl Bromides

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(4)

Опубликована: Ноя. 26, 2022

Abstract Catalytic, three‐component, cross‐electrophile reactions have recently emerged as a promising tool for molecular diversification, but studies focused mainly on the alkyl‐carbonations of alkenes. Herein, scope this method has been extended to conjugated dienes and silicon chemistry through silylative difunctionalization 1,3‐dienes with chlorosilanes aryl bromides. The reaction proceeds under mild conditions afford 1,2‐linear‐silylated products, selectivity that is different those obtained from conventional methods via an intermediary H(C)‐η 3 ‐π‐allylmetal species. Preliminary mechanistic reveal chlorosilane reacts 1,3‐diene first then couples bromide.

Язык: Английский

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O-Allylhydroxyamine: A Bifunctional Olefin for Construction of Axially and Centrally Chiral Amino Alcohols via Asymmetric Carboamidation

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(14), С. 8150 - 8162

Опубликована: Апрель 4, 2023

Difunctionalization of olefins offers an attractive approach to access complex chiral structures. Reported herein is the design N-protected O-allylhydroxyamines as bifunctional that undergo catalytic asymmetric 1,2-carboamidation with three classes (hetero)arenes afford amino alcohols via C-H activation. The C═C bond in O-allylhydroxyamine activated by intramolecular electrophilic amidating moiety well a migrating directing group. carboamidation reaction pattern depends on nature (hetero)arene reagent. Simple achiral reacted give centrally β-amino excellent enantioselectivity. employment axially prochiral or racemic heteroarenes afforded both axial and central chirality enantio- diastereoselectivity. In case heteroarenes, coupling follows kinetic resolution s-factor up >600. A nitrene-based mechanism has been suggested based experimental studies, unique mode induction diastereoselectivity proposed. Applications alcohol products have demonstrated.

Язык: Английский

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Directed Asymmetric Nickel‐Catalyzed Reductive 1,2‐Diarylation of Electronically Unactivated Alkenes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(13)

Опубликована: Янв. 31, 2023

Transition-metal catalyzed intermolecular 1,2-diarylation of electronically unactivated alkenes has emerged as an extensive research topic in organic synthesis. However, most examples are mainly limited to terminal alkenes. Furthermore, transition-metal asymmetric still remains unsolved and is a formidable challenge. Herein, we describe highly efficient directed nickel-catalyzed reductive internal with high diastereoselectivities. More importantly, our further effort towards enantioselective the challenging achieved, furnishing various polyarylalkanes featuring benzylic stereocenters yields good enantioselectivities Interestingly, generation cationic Ni-catalyst by adding alkali metal fluoride key increased efficiency this reaction.

Язык: Английский

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Nickel-Catalyzed Radical Mechanisms: Informing Cross-Coupling for Synthesizing Non-Canonical Biomolecules

Accounts of Chemical Research, Год журнала: 2023, Номер 56(24), С. 3640 - 3653

Опубликована: Ноя. 30, 2023

ConspectusNickel excels at facilitating selective radical chemistry, playing a pivotal role in metalloenzyme catalysis and modern cross-coupling reactions. Radicals, being nonpolar neutral, exhibit orthogonal reactivity to nucleophilic basic functional groups commonly present biomolecules. Harnessing this compatibility, we delve into the application of nickel-catalyzed pathways synthesis noncanonical peptides carbohydrates, critical for chemical biology studies drug discovery.We previously characterized sequential reduction mechanism that accounts chemoselectivity cross-electrophile coupling This catalytic cycle begins with nickel(I)-mediated generation from alkyl halides, followed by carbon capture nickel(II) complexes, concludes reductive elimination. These steps resonate mechanistic proposals cross-coupling, photoredox, electrocatalytic Herein, our insights each step involving radicals, including initiation, propagation, termination, nuances kinetics, origins selectivity, ligand effects.Radical C(sp3) electrophiles via one-electron oxidative addition low-valent nickel intermediates provides basis stereoconvergent couplings. Our electroanalytical elucidate concerted halogen atom abstraction mechanism, where electron transfer is coupled halide dissociation. Using pathway, have developed stereoselective dehydroalanine, peptides. In application, chiral ligands modulate stereochemical outcome through asymmetric protonation nickel-enolate intermediate.The expands scope promotes elimination formation high-valent nickel(III) species, governs chemo- stereoselectivity. We discovered nickel(II)-aryl efficiently traps radicals barrier ranging 7 9 kcal/mol, fast contrast, nickel(II)-alkyl captures form which was EPR spectroscopy. However, subsequent slow resulted minimal product formation. The observed high diastereoselectivity inspired investigations C-aryl C-acyl glycosylation redox auxiliary readily couples natural carbohydrates produces glycosyl upon photoredox activation. Nickel-catalyzed bromoarenes carboxylic acids leads diverse non-natural glycosides can facilitate discovery.Stoichiometric on well-defined d8-nickel complexes showcased means promote elimination, association, oxidation, addition.In final section, address influence electronic structure activity organonickel intermediates. Synthesis series characterization their structures led us postulate correlates coordination geometry. data reveal change shift potentials reaction intermediates, potentially altering Moreover, coordinating additives solvents may stabilize during adjusting activity, consistent known conditions.

Язык: Английский

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