Asymmetric Cross-Coupling of Aldehydes with Diverse Carbonyl or Iminyl Compounds by Photoredox-Mediated Cobalt Catalysis

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(15), С. 10857 - 10867

Опубликована: Апрель 8, 2024

The asymmetric cross-coupling of unsaturated bonds, hampered by their comparable polarity and reactivity, as well the scarcity efficient catalytic systems capable diastereo- enantiocontrol, presents a significant hurdle in organic synthesis. In this study, we introduce highly adaptable photochemical cobalt catalysis framework that facilitates chemo- stereoselective reductive cross-couplings between common aldehydes with broad array carbonyl iminyl compounds, including N-acylhydrazones, aryl ketones, aldehydes, α-keto esters. Our methodology hinges on synergistic mechanism driven photoredox-induced single-electron reduction subsequent radical–radical coupling, all precisely guided chiral catalyst. Various optically enriched β-amino alcohols unsymmetrical 1,2-diol derivatives (80 examples) have been synthesized good yields (up to 90% yield) high stereoselectivities >20:1 dr, 99% ee). Of particular note, approach accomplishes unattainable transformations disparate partners without reliance any external photosensitizer, thereby further emphasizing its versatility cost-efficiency.

Язык: Английский

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Catalytic Asymmetric Dearomative [2 + 2] Photocycloaddition/Ring-Expansion Sequence of Indoles with Diversified Alkenes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(33), С. 23457 - 23466

Опубликована: Июль 12, 2024

Developing novel strategies for catalytic asymmetric dearomatization (CADA) reactions is highly valuable. Visible light-mediated photocatalysis demonstrated to be a powerful tool activate aromatic compounds further synthetic transformations. Herein, dearomative [2 + 2] photocycloaddition/ring-expansion sequence of indoles with simple alkenes was reported, providing facile access enantioenriched cyclopenta[

Язык: Английский

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Quinone-Initiated Photocatalytic Enantioselective Giese Radical Addition with Ethers, Thioethers, Amines, and Alkanes

ACS Catalysis, Год журнала: 2024, Номер 14(16), С. 12031 - 12041

Опубликована: Июль 29, 2024

Photocatalytic enantioselective Giese radical addition with inert C(sp3)–H bonds represents a highly efficient and economically favorable approach to synthesizing diverse value-added chiral molecules from abundant feedstock. Herein, we disclose quinone-initiated photocatalytic asymmetric of α-substituted acrylamides by applying simple quinones as HAT photocatalysts in combination N,N′-dioxide/praseodymium(III) catalyst. A wide array ethers, thioethers, selenide, amines, alkanes can smoothly transform into the corresponding α-aryl amide derivatives satisfactory enantioselectivities (68 examples, up 95% ee) under mild conditions. Based on spectroscopy studies control experiments, catalytic cycle was proposed, DFT calculations revealed that interaction between quinone Lewis acid essential for enantio-induction back hydrogen atom transfer process.

Язык: Английский

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Iron‐Catalyzed Asymmetric α‐Alkylation of 2‐Acylimidazoles via Dehydrogenative Radical Cross‐Coupling with Alkanes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(1)

Опубликована: Ноя. 21, 2023

The direct α-alkylation of acyclic carbonyls with nonactivated hydrocarbons through C(sp3 )-H functionalization is both extremely promising and notably challenging, especially when attempting to achieve enantioselectivity using iron-based catalysts. We have identified a robust chiral iron complex for the oxidative cross-coupling 2-acylimidazoles benzylic allylic hydrocarbons, as well alkanes. readily available tunable N,N'-dioxide catalysts in connection oxidants exhibit precise asymmetric induction (up 99 % ee) good compatibility moderate yields 88 yield). This protocol provides an elegant straightforward access optically active carbonyl derivatives starting from simple alkanes without prefunctionalization. Density functional theory (DFT) calculations control experiments were made gain insight into nature C-C bond formation origin enantioselectivity. propose radical-radical process enabled by immediate interconversion between ferric species ferrous species.

Язык: Английский

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Applications of Organosilanes in Visible Light‐induced Catalytic Asymmetric Reactions

ChemCatChem, Год журнала: 2024, Номер unknown

Опубликована: Март 27, 2024

Abstract Over the past decades, visible light‐mediated photocatalysis has found a mainstream of applications in synthetic chemistry. Organosilanes have been proven to be useful class electron donors generate highly active radical species via photoinduced single transfer oxidation/fragmentation sequence, which may undergo follow‐up coupling or addition process. This minireview highlights comprehensive advances organosilanes photoredox catalyzed asymmetric organic synthesis, with particular emphasis placed on reaction mechanisms. We hope that this review will inspire further design and development new reactions such readily accessible reagents.

Язык: Английский

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Visible-light-driven asymmetric aldol reaction of ketones and glycinates via synergistic Lewis acid/photoredox catalysis

Chemical Science, Год журнала: 2024, Номер 15(39), С. 16050 - 16058

Опубликована: Янв. 1, 2024

We have synthesized β-diaryl-β-hydroxyl-α-amino acid derivatives through radical addition-type aldol reaction, which was confirmed by spectroscopic experiments, control and DFT calculations.

Язык: Английский

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Enantioselective Hydroaminoalkylation of Azaaryl Ketones through Asymmetric Photoredox Catalysis

Organic Letters, Год журнала: 2024, Номер 26(23), С. 5037 - 5042

Опубликована: Июнь 5, 2024

An enantioselective hydroaminoalkylation of azaaryl ketones under a transition-metal-free asymmetric photoredox catalysis platform is reported. A series valuable azaarene-functionalized 1,2-amino alcohols featuring attractive quaternary carbon stereocenters have been synthesized in high yields with good to excellent enantioselectivities. The viability readily accessible N-aryl glycines as reaction partners facilitates the conjugate modification these products into important derivatives, thereby enhancing synthetic utility current approach.

Язык: Английский

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Aza-[4 + 2]-cycloaddition of benzocyclobutenones into isoquinolinone derivatives enabled by photoinduced regio-specific C–C bond cleavage

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Дек. 30, 2024

The activation of C-C bond benzocyclobutenones under mild reaction conditions remains a challenge. We herein report photoinduced catalyst-free regio-specific C1-C8 cleavage benzocyclobutenones, enabling the generation versatile ortho-quinoid ketene methides for aza-[4 + 2]-cycloaddition with imines, which offers facile route to isoquinolinone derivatives, including seven family members protoberberine alkaloids, gusanlung A, B, D, 8-oxotetrahydroplamatine, tetrahydrothalifendine, tetrahydropalmatine, and xylopinine. Furthermore, catalytic enantioselective version this strategy is also realized by merging synergistic photocatalysis chiral Lewis acid catalysis. Mechanistic studies provide compelling evidence rationalize photoisomerization/cycloaddition cascade process.

Язык: Английский

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Catalytic Asymmetric Synthesis of β-Amino α-Tertiary Alcohol through Borrowing Hydrogen Amination

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 6, 2025

The first enantioconvergent transition-metal-catalyzed amination of racemic α-tertiary 1,2-diols providing access to vicinal β-amino alcohols is disclosed. iridium-catalyzed reaction proceeds through a chiral phosphoric acid-mediated borrowing hydrogen pathway with excellent yields and enantioselectivities for range amine nucleophiles 1,2-diols. An array were obtained high (50 examples up 91% yield 99% ee). These important amino alcohol products can be easily converted into ligands bioactive skeletons. Mechanistic investigations proposed dynamic kinetic resolution involving imine formation then reduction as the enantiodetermining step.

Язык: Английский

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Reduction of C=X to CH–XH by Dissolving Metals and Related Methods

Elsevier eBooks, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Язык: Английский

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