Stereodivergent Synthesis of Allenes with α,β‐Adjacent Central Chiralities Empowered by Synergistic Pd/Cu Catalysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(9)

Опубликована: Янв. 3, 2023

The stereodivergent synthesis of allene compounds bearing α,β-adjacent central chiralities has been realized via the Pd/Cu-catalyzed dynamic kinetic asymmetric alkylation racemic allenylic esters. matched reactivity bimetallic catalytic system enables challenging reaction aryl-substituted acetates with sterically crowded aldimine esters smoothly under mild conditions. Various chiral non-natural amino acids a terminal allenyl group are easily synthesized in high yields and excellent diastereo- enantioselectivities (up to >20 : 1 dr, >99 % ee). Importantly, all four stereoisomers product can be readily accessed by switching configurations two metal catalysts. Furthermore, easy interconversion between uncommon η3 -butadienyl palladium intermediate featuring weak C=C/Pd coordination bond stable Csp2 -Pd is beneficial for transformation process (DyKAT).

Язык: Английский

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Asymmetric C3-Allylation of Pyridines

Journal of the American Chemical Society, Год журнала: 2023, Номер unknown

Опубликована: Май 17, 2023

Asymmetric intermolecular C–H functionalization of pyridines at C3 is unprecedented. Herein, we report the first examples such transformations: specifically, C3-allylation via tandem borane and iridium catalysis. First, borane-catalyzed pyridine hydroboration generates nucleophilic dihydropyridines; then, dihydropyridine undergoes enantioselective iridium-catalyzed allylation; finally, oxidative aromatization with air as oxidant gives C3-allylated pyridine. This protocol provides direct access to excellent enantioselectivity (up >99% ee) suitable for late-stage pyridine-containing drugs.

Язык: Английский

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Stereodivergent Construction of 1,3‐Chiral Centers via Tandem Asymmetric Conjugate Addition and Allylic Substitution Reaction

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(10)

Опубликована: Янв. 4, 2023

Herein, we report a synthesis of cyclohexanones bearing multi-continuous stereocenters by combining copper-catalyzed asymmetric conjugate addition dialkylzinc reagents to cyclic enones with iridium-catalyzed allylic substitution reaction. Good excellent yields, diastereoselectivity and enantioselectivity can be obtained. Unlike the stereodivergent construction adjacent (1,2-position) reported in literature, current reaction achieve nonadjacent (1,3-position) proper combination two chiral catalysts different enantiomers.

Язык: Английский

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Enantioselective C3‐Allylation of Pyridines via Tandem Borane and Palladium Catalysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(34)

Опубликована: Июль 3, 2023

Abstract Herein, we report a one‐pot method for enantioselective C−H allylation of pyridines at C3 via tandem borane and palladium catalysis. This involves borane‐catalyzed pyridine hydroboration to generate dihydropyridines, then palladium‐catalyzed the dihydropyridines with allylic esters, finally air oxidation allylated afford products. enables introduction an group excellent regio‐ enantioselectivities.

Язык: Английский

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Ir‐Catalyzed Enantioselective Synthesis of gem‐Diborylalkenes Enabled by 1,2‐Boron Shift

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(32)

Опубликована: Июнь 15, 2023

Abstract Asymmetric cross‐couplings based on 1,2‐carbon migration from B‐ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by 1,2‐boron shift remained be unaddressed synthetic challenge. Here, Ir‐catalyzed asymmetric allylic alkylation enabled was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of carbonates at the elevated temperature. Notably, highly (bis‐boryl)alkenes array diversifications versatile molecules. Extensive experimental and computational studies conducted elucidate reaction mechanism DKR clarify origin enantioselectivities.

Язык: Английский

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Decarboxylative Alkylation of Morita–Baylis–Hillman Acetates with Aliphatic Acids via Photochemical Iron-Mediated Ligand-to-Metal Charge Transfer

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Фев. 28, 2025

Carboxylic acids are bench-stable and readily available chemical feedstocks that function as optimal fundamental synthetic platforms for the construction of C(sp3)–C(sp3) bonds via decarboxylation processes. We present a novel practical protocol decarboxylative alkylation Morita–Baylis–Hillman acetates with various carboxylic photoinduced iron-mediated ligand-to-metal charge transfer (LMCT) process under redox-neutral conditions. This method exhibits remarkable tolerance to wide array acids, including primary, secondary, tertiary obviating requirement preactivated radical precursors. The preliminary mechanistic analyses indicate pathway is involved in this catalytic transformation.

Язык: Английский

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Regio- and Enantioselective Allylic Cyanomethylation by Synergistic Rhodium and Silane Catalysis

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(7), С. 3897 - 3902

Опубликована: Фев. 8, 2023

Rh/silane-cocatalyzed regio- and enantioselctive allylic cyanomethylation with inert acetonitrile directly has been developed. Addition of a catalytic amount neutral silane reagent as an anion carrier is essential for the success this reaction. The synthesis mono- bis-allylation products can be switched by adjusting size substituents on silane, ligands, temperature. Chiral homoallylic nitriles could synthesized in above 20:1 branch/linear ratio, up to 98% yield >99% ee.

Язык: Английский

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Asymmetric Synthesis of Chiral 1,2‐Bis(Boronic) Esters Featuring Acyclic, Non‐Adjacent 1,3‐Stereocenters

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(5)

Опубликована: Дек. 15, 2023

The construction of acyclic, non-adjacent 1,3-stereogenic centers, prevalent motifs in drugs and bioactive molecules, has been a long-standing synthetic challenge due to acyclic nucleophiles being distant from the chiral environment. In this study, we successfully synthesized highly valuable 1,2-bis(boronic) esters featuring nonadjacent 1,3-stereocenters. Notably, reaction selectively produces migratory coupling products rather than alternative deborylative allylation or direct byproducts. This approach introduces new activation mode for selective transformations gem-diborylmethane asymmetric catalysis. Additionally, found that other gem-diborylalkanes, previously challenging steric hindrance, also participated reaction. incorporation 1,2-bis(boryl)alkenes facilitated diversification alkenyl two boron moieties our target compounds, thereby enabling access broad array versatile molecules. DFT calculations were performed elucidate mechanism shed light on factors responsible observed excellent enantioselectivity diastereoselectivity. These determined arise ligand-substrate repulsions syn-addition transition state.

Язык: Английский

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Cooperative Isothiourea/Iridium-Catalyzed Asymmetric Annulation Reactions of Vinyl Aziridines with Pentafluorophenyl Esters

Organic Letters, Год журнала: 2023, Номер 25(8), С. 1246 - 1251

Опубликована: Фев. 23, 2023

Chiral γ-lactam-containing skeletons are important motifs in bioactive natural products, pharmaceuticals, and molecules. Herein, we report a general modular platform to access chiral γ-lactam compounds via an ITU/Ir cooperatively catalyzed [3 + 2] asymmetric annulation reaction of vinyl aziridines with pentafluorophenyl esters. Through the Lewis base transition metal cooperative catalytic regime, broad range optically active γ-lactams were generated good yields (up 92%) high induction 98% ee). Furthermore, utility this synthetic protocol was also demonstrated by expedient preparation diverse enantioenriched architectures.

Язык: Английский

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Construction of Vicinal Quaternary Centers via Ru-Catalyzed Enantiospecific Allylic Substitution with Lithium Ester Enolates

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(34), С. 23674 - 23679

Опубликована: Авг. 19, 2024

The installation of vicinal quaternary centers with absolute stereocontrol constitutes a considerable challenge in organic synthesis. Herein, we introduce novel [Cp*Ru(MeCN)

Язык: Английский

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