Enantioselective Reductive (Hetero)Arylation of Cyclic N‐Sulfonyl Imines by Cobalt Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(19)

Published: March 14, 2023

Transition-metal-catalyzed enantioselective addition of aryl organometallic reagents to imines has emerged as one the most powerful tools for formation optically active diarylmethylamines. Here, we report first asymmetric reductive (hetero)arylations using and heteroaryl halides enabled by a chiral cobalt-bisphosphine catalyst. This approach shows good functional group compatibility complements reported strategy without use reagents. Mechanistic investigations supported that aryl-cobalt, instead an arylzinc reagent, was formed in situ this aryl-addition event.

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10857 - 10867

Published: April 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.

Language: Английский

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Expedient Synthesis of Axially and Centrally Chiral Diaryl Ethers via Cobalt-Catalyzed Photoreductive Desymmetrization

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(7), P. 4638 - 4647

Published: March 12, 2024

Axially chiral diaryl ethers make up a unique class of atropisomers bearing restricted rotation about the C–O bond. Methods for expedient synthesis axially ether-based structures have been largely underdeveloped. Herein, we developed an efficient metal-catalyzed desymmetrization strategy to unveil formation and centrally dual in high diastereo- enantioselectivity. The protocol leverages cobalt-catalyzed photoreductive enantioselective couplings dialdehyde alkyne deliver stereogenicity, ether scaffold is equipped with useful synthetic handles including formyl, hydroxyl, allyl groups, as has demonstrated carboxylic acid potential ligand asymmetric catalysis.

Language: Английский

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Cobalt‐Catalyzed Enantioselective Reductive α‐Chloro‐Carbonyl Addition of Ketimine to Construct the β‐Tertiary Amino Acid Analogues

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(25)

Published: Jan. 22, 2024

β-Tertiary amino acid derivatives constitute one of the most frequently occurring units in natural products and bioactive molecules. However, efficient asymmetric synthesis this motif still remains a significant challenge. Herein, we disclose cobalt-catalyzed enantioselective reductive addition reaction ketimine using α-chloro carbonyl compound as radical precursor, providing expedient access to diverse array enantioenriched β-quaternary analogues. This protocol exhibits outstanding enantioselectivity broad substrate scope with excellent functional group tolerance. Preliminary mechanism studies rule out possibility Reformatsky-type confirm involvement species stereoselective process. The synthetic utility has been demonstrated through rapid assembly iterative oligopeptide, showcasing its versatile platform for late-stage modification drug candidates.

Language: Английский

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Nickel-Catalyzed Enantioselective Reductive Arylation of Common Ketones

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(19), P. 12895 - 12900

Published: May 2, 2024

A nickel complex of chiral bisoxazolines catalyzed the stereoselective reductive arylation ketones in high enantioselectivity. range common acyclic and cyclic reacted without aid directing groups. Mechanistic studies using isolated a bis(oxazoline) (L)Ni(Ar)Br revealed that Mn reduction was not needed, while Lewis acidic titanium alkoxides were critical to ketone insertion.

Language: Английский

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Cobalt‐Catalyzed Enantioselective Alkenylation of Aldehydes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(33)

Published: May 31, 2024

Catalytic enantioselective alkenylation of aldehydes with easily accessible alkenyl halides promoted by a chiral cobalt complex derived from newly developed tridentate bisoxazolinephosphine is presented. Such processes represent an unprecedented reaction pathway for catalysis and general approach that enable rapid construction highly diversified enantioenriched allylic alcohols containing 1,1-, 1,2-disubstituted trisubstituted alkene as well axial stereogenicity in up to 99 % yield : 1 er without the need preformation alkenyl-metal reagents. DFT calculations revealed origin enantioselectivity.

Language: Английский

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Selective Reductive Coupling of Vinyl Azaarenes and Alkynes via Photoredox Cobalt Dual Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(1)

Published: Sept. 30, 2022

A visible light-induced Co-catalyzed highly regio- and stereoselective reductive coupling of vinyl azaarenes alkynes has been developed. Notably, Hünig's base together with simple ethanol successfully applied as the hydrogen sources instead commonly used Hantzsch esters in this catalytic photoredox reaction. This approach considerable advantages for straightforward synthesis stereodefined multiple substituted alkenes bearing an azaarene motif, such excellent regioselectivity (>20 : 1 >30 examples) stereoselectivity E/Z), broad substrate scope good functional group compatibility under mild reaction conditions, which utilized concise natural product monomorine I. reasonable pathway involving protolysis cobaltacyclopentene intermediate proposed based on mechanistic studies.

Language: Английский

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Nickel-Catalyzed Enantioselective Coupling of Acid Chlorides with α-Bromobenzoates: An Asymmetric Acyloin Synthesis

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(50), P. 23019 - 23029

Published: Dec. 8, 2022

The reaction of common acyl-metal species (acyl anion) with aldehydes to furnish acyloins has received much less attention and specifically was restricted using preformed stoichiometric reagents. Moreover, the (catalytic) enantioselective variants remain unexplored, asymmetric synthesis chiral met significant challenges in organic synthesis. Here, we uncover highly coupling acid chlorides α-bromobenzoates by nickel catalysis for producing enantioenriched protected α-hydroxy ketones (acyloins, >60 examples) high enantioselectivities (up 99% ee). successful execution this protocol enables formation a key ketyl radical from α-bromoalkyl benzoate situ generated corresponding aldehyde acyl bromide, which finally is captured acyl-Ni catalytically formed chlorides, thus avoiding use synthetic utility chemistry demonstrated downstream elaboration toward diverse set synthetically valuable building blocks biologically active compounds.

Language: Английский

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Recent Advances in Nonprecious Metal Catalysis

Organic Process Research & Development, Journal Year: 2023, Volume and Issue: 27(3), P. 423 - 447

Published: Feb. 17, 2023

Nonprecious-metal-catalyzed alternatives to powerful precious metal transformations are of increasing interest in academia and the pharmaceutical industry due lower cost, better sustainability, toxicity. With continual growth broad field nonprecious catalysis (NPMC), we have chosen highlight selected articles published from March June 2022 which intended examples NPMC that feel may be especially relevant development. We aim inspire academic industrial innovation through discussion herein.

Language: Английский

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Photoredox/Nickel Dual Catalysis-Enabled Modular Synthesis of Arylallyl Alcohols with Acetylene as the Two-Carbon Synthon

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(4), P. 2422 - 2431

Published: Feb. 2, 2023

Arylallyl alcohols are commonly found in natural products and drug molecules. The traditional syntheses primarily rely on two-component reactions using presynthesized alkenes. Herein, we report a photoredox/nickel dual-catalyzed three-component cross-coupling reaction, which enables the rapid synthesis of arylallyl with acetylene as two-carbon (C2) synthon. In this aryl halide carbonyl compound were sewn together linker. A series synthesized an atmosphere (1 atm). This method features broad substrate scopes, good functional group tolerance, high Z-selectivity. addition to intermolecular difunctionalization acetylene, reaction is also amenable intramolecular ring formation, giving highly valuable indenols indanones. mechanistic investigation indicates that alkenylnickel key intermediate. intermediate can be considered alternative alkenyl Grignard reagent but better compatibility. With step, several important molecules including have been prepared.

Language: Английский

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