Enantioselective Potassium-Catalyzed Wittig Olefinations

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(11), С. 7165 - 7172

Опубликована: Март 7, 2024

We report asymmetric potassium–isothiourea–boronate-catalyzed Wittig olefinations of 4-substituted cyclohexanones with non-stabilized phosphorus ylides to afford highly enantioenriched axially chiral alkenes. The optimal catalyst features an unusual macrocyclic amide–potassium–boronate chelate. Kinetic and spectroscopic analyses are consistent a Lewis acid mechanism for the catalytic olefination that results in formation oxaphosphetane adduct under cryogenic conditions. Thermal fragmentation alkene product occurs after reaction is complete. Computational studies indicate cycloaddition proceeds via stepwise involving enantiodetermining polar 1,2-addition intermediate potassium betaine complex.

Язык: Английский

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Enantioselective Synthesis of Axially Chiral Alkylidenecycloalkanes via Copper-Catalyzed Functionalization of Acyl Allenols

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 2351 - 2358

Опубликована: Янв. 24, 2025

Язык: Английский

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Enantioselective Construction of Anthracenylidene-Based Axial Chirality by Asymmetric Heck Reaction

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(28), С. 19137 - 19145

Опубликована: Июль 2, 2024

Anthracenylidene is an intriguing structural unit with potential in various fields. The study presents a novel approach to introducing axial chirality into this all-carbon core skeleton through remotely controlled desymmetrization strategy. A palladium-catalyzed enantioselective Heck arylation of exocyclic double bond anthracene two distinct substituents at the C10 position harnessed realize such transformation. judicious identification P-centrally chiral ligand pivotal ensure competitive competence reactivity and stereocontrol when heteroatom handle absent from anthracenylidene skeleton. Both mono- disubstituted substrates were compatible for established catalytic system, structurally diverse anthracenylidene-based frameworks forged good-to-high enantiocontrol. subsequent derivatization obtained products yielded valuable array centrally axially molecules, thus emphasizing practicality chemistry. DFT calculations shed light on mechanism provided insights origin experimentally observed enantioselectivity reaction.

Язык: Английский

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Pd-catalyzed enantioselective synthesis of axially chiral alkylidene cycloalkanes

Chem Catalysis, Год журнала: 2023, Номер 3(7), С. 100697 - 100697

Опубликована: Июль 1, 2023

Язык: Английский

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Stable Axially Chiral Cyclohexylidenes from Catalytic Asymmetric Knoevenagel Condensation

Chemistry - A European Journal, Год журнала: 2024, Номер 30(39)

Опубликована: Май 7, 2024

Axially chiral cycloalkylidenes are interesting but less developed axially molecules. Here, a bispidine-based amine catalytic system was to promote efficiently the asymmetric Knoevenagel condensation of N-protected oxindoles and benzofuranones with 4-substituted cyclohexanones. A variety alkylidenecycloalkanes stable axial chirality were obtained in good yields fairly er (enantiomeric ratio). Based on absolute configuration determination product DFT calculations, possible mechanism stereoselective induction proposed.

Язык: Английский

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Cu-catalyzed enantioselective assembly of axially chiral allylic boronates

Science China Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Окт. 25, 2024

Язык: Английский

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Phosphoric Acid-Catalyzed Enantioselective Synthesis of Axially Chiral Cyclobutanamides

Organic Letters, Год журнала: 2025, Номер 27(10), С. 2509 - 2514

Опубликована: Март 5, 2025

Chiral cyclobutanamide is a privileged scaffold in drug discovery. Here, we describe, for the first time, synthesis of axially chiral cyclobutanamides via phosphoric acid-catalyzed enantioselective condensation between N-arylcarbamyl cyclobutanones and hydroxylamines. Rational substrate design, incorporating an amide moiety (CONHR) into cyclobutanone backbone formation multi-hydrogen bonding network involving N-H this portion, responsible excellent enantioselectivity achieved stereodetermining dehydration process, which supported by detailed mechanistic study.

Язык: Английский

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Rh(I)-Catalyzed Modular Synthesis of Axially Chiral Alkylidene Azacycloalkanes

ACS Central Science, Год журнала: 2025, Номер unknown

Опубликована: Май 11, 2025

Язык: Английский

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Enantioselective Synthesis of Axially Chiral Alkylidenecyclobutanes via Palladium-Catalyzed N-Tosylhydrazone-Based Carbene Coupling

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Май 11, 2025

The synthesis of axially chiral alkylidenecyclobutanes remains challenging due to the requirement both an efficient asymmetric catalytic system and preservation its inherent strained ring structure. We herein disclose enantioselective carbene cross-coupling reaction cyclobutanecarbaldehyde-derived N-tosylhydrazones with aryl bromides, enabled by palladium catalysis in combination elaborately modified sulfinamide phosphine ligand (Sadphos). This method demonstrates feasibility constructing axial chirality on a metal intermediate precisely through sequential process enantiodetermined migratory insertion followed central-to-axial-chirality-transfer β-H elimination. provides access diverse featuring heteroatom-substituted, tertiary all-carbon quaternary stereocenter excellent yields (up 95%) high enantioselectivities 95% ee). Moreover, enantiomers can be selectively obtained choosing either cis- or trans-cyclobutane substrates stereospecific manner.

Язык: Английский

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Axial Chirality in Alkylidene‐Cyclic Molecules

European Journal of Organic Chemistry, Год журнала: 2023, Номер 26(20)

Опубликована: Март 30, 2023

Abstract Axial chirality is an interesting stereoisomeric phenomenon in organic chemistry and a key structural feature of several compounds. Atropisomers such as biaryls, anilides diaryl ethers are one type axially chiral compounds, whose axial resulted from rotationally blocked single bond. Allenes, spiranes alkylidenecycloalkanes another compounds their come the perpendicular geometry two pairs substituents. The atropisomers, allenes has been widely investigated well developed, while similar alkylidene‐cyclic molecules gained very limited attentions. This concept focuses on summarizing recent advances arouses research interests to this promising field.

Язык: Английский

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