Enantioselective Synthesis of Medium-Sized-Ring Lactones via Iridium-Catalyzed Z-Retentive Asymmetric Allylic Substitution Reaction

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(11), С. 4770 - 4775

Опубликована: Март 10, 2022

Medium-sized rings are important structural units, but their synthesis, especially in a highly enantioselective manner, has been great challenge. Herein we report an synthesis of medium-sized-ring lactones by iridium-catalyzed Z-retentive asymmetric allylic substitution reaction. The reaction features mild conditions and broad substrate scope. Various eight- to 11-membered-ring can be afforded moderate excellent yields (up 88%) enantioselectivity 99% ee). utilization both Z-allyl precursors Ir catalyst is critical for the formation.

Язык: Английский

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Recent applications of vinylethylene carbonates in Pd-catalyzed allylic substitution and annulation reactions: Synthesis of multifunctional allylic and cyclic structural motifs

Coordination Chemistry Reviews, Год журнала: 2022, Номер 462, С. 214526 - 214526

Опубликована: Март 30, 2022

Язык: Английский

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Z-Retentive Asymmetric Allylic Substitution Reactions of Aldimine Esters under Ru/Cu Dual Catalysis

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(7), С. 4333 - 4339

Опубликована: Фев. 7, 2024

Ru/Cu dual catalysis has been applied for

Язык: Английский

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Asymmetric Three-Component Reaction to Assemble the Acyclic All-Carbon Quaternary Stereocenter via Visible Light and Phosphoric Acid Catalysis

ACS Catalysis, Год журнала: 2022, Номер 12(21), С. 13282 - 13291

Опубликована: Окт. 17, 2022

Chiral acyclic all-carbon quaternary stereocenters are widely present in natural products and pharmaceuticals. However, their introduction remains a challenging topic the synthetic research community. Here, we report an efficient metal-free method for construction of chiral centers sited at α-position aldehyde or ketone moiety. This is achieved via well-designed reaction cascade involving arylalkynes, benzoquinones, electron-rich (hetero)arenes use visible light phosphoric acid catalysis. Notably, asymmetric catalytic visible-light-induced Paternò–Büchi cycloaddition/electrocyclic ring-opening/α-selective arylation α,β-unsaturated carbonyl compound cascades achieved. Moreover, works well broad range these three components (>70 examples). Furthermore, rich chemistry embedded provides variety synthetically useful building blocks that otherwise difficult to access. Lastly, origin enantioselectivity was investigated by density functional theory, revealing CH/π interactions play crucial role stereocontrol reaction.

Язык: Английский

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Rh(II)-Catalyzed Enantioselective S-Alkylation of Sulfenamides with Acceptor–Acceptor Diazo Compounds Enables the Synthesis of Sulfoximines Displaying Diverse Functionality

Organic Letters, Год журнала: 2024, Номер 26(29), С. 6295 - 6300

Опубликована: Июль 15, 2024

The Rh(II)-catalyzed enantioselective S-alkylation of sulfenamides with α-amide diazoacetates at 1 mol % catalyst loading to obtain sulfilimines in high yields and enantiomeric ratios up 99:1 is reported. enantioenriched sulfilimine products incorporate versatile amide functionality poised for further elaboration diverse sulfoximines multiple stereogenic centers, including by highly diastereoselective sulfoximine α-alkylation alkylating agents epoxides interconversion the N-tert-butanesulfinyl aldimines, followed additions.

Язык: Английский

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Palladium-catalyzed enantioselective decarboxylative allylic alkylation of fully substituted N-acyl indole-derived enol carbonates

Chemical Science, Год журнала: 2019, Номер 10(23), С. 5996 - 6000

Опубликована: Янв. 1, 2019

The first enantioselective palladium-catalyzed decarboxylative allylic alkylation of fully substituted N-acyl indole-derived enol carbonates forming acyclic all-carbon quaternary stereocenters is reported. Excellent yields up to 99% and enantioselectivities 98% ee are obtained through the use a new electron-deficient phosphinoxazoline (PHOX) ligand. Control substrate enolate geometry crucial for high selectivity. α-quaternary indoles formal ester equivalents, represent useful handle further synthetic transformations.

Язык: Английский

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Asymmetric Allylic Alkylation of β-Ketoesters via C–N Bond Cleavage of N-Allyl-N-methylaniline Derivatives Catalyzed by a Nickel–Diphosphine System

ACS Catalysis, Год журнала: 2020, Номер 10(10), С. 5828 - 5839

Опубликована: Апрель 22, 2020

Nickel complexes bearing chiral diphosphine ligands, such as (S)-Tol-MeO-BIPHEP and (S)-H8-BINAP, serve efficient catalysts for asymmetric allylic alkylation (AAA) of β-ketoesters, using amines allyl sources. The reactions proceed with high catalytic activity enantioselectivity. N-Methyl-N-phenyl were indispensable to achieve the activity, enantioselectivity, expand substrate scope 5- 7-membered whose nickel-catalyzed AAA alcohols results in low On basis kinetics a catalyst system made Ni(cod)2 (S)-Tol-MeO-BIPHEP, DFT calculations reaction pathway mediated by an isolated olefin-coordinated nickel–DPPF complex 4b, we propose mechanism where protonation nitrogen atom coordinating amine β-ketoester is key cleaving C–N bond delivering cationic π-allyl nickel(II) intermediate.

Язык: Английский

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Asymmetric construction of acyclic quaternary stereocenters via direct enantioselective additions of α-alkynyl ketones to allenamides

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Ноя. 18, 2021

Abstract Acyclic quaternary stereocenters are widely present in a series of biologically active natural products and pharmaceuticals. However, development highly efficient asymmetric catalytic methods for the construction these privileged motifs represents longstanding challenge organic synthesis. Herein, an chiral phosphoric acid catalyzed direct addition α-alkynyl acyclic ketones with allenamides has been developed, furnishing all-carbon excellent regioselectivities high enantioselectivities. Extensive detailed experimental mechanistic studies were performed to investigate mechanism this reaction. Despite novel covalent allyl phosphate intermediate was found reactions, further indicated that S N 2-type ketone nucleophiles is not very possible. Instead, more plausible involving elimination give α,β-unsaturated iminium intermediate, which underwent conjugate enol form under anion catalysis, proposed. In virtue fruitful functional groups bearing products, diverse derivatizations provided access wide array scaffolds stereocenters.

Язык: Английский

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Efficient Synthesis of Diaryl Quaternary Centers by Rh(II)/Xantphos Catalyzed Relay C−H Functionalization and Allylic Alkylation

Chemistry - A European Journal, Год журнала: 2022, Номер 29(3)

Опубликована: Окт. 14, 2022

A three-component reaction of N, N-disubstituted aniline, α-diazo ester, and an allylic electrophile has been realized by [Rh(II)]2 /Xantphos catalysis, providing a direct access to various aniline derivatives bearing diaryl quaternary centers in good yields. The synthetic utility this protocol was demonstrated facile derivatization the products for preparation biologically relevant molecules structural scaffolds, which offers high potential increasing molecular diversity. Mechanistic studies identified α, α-diarylacetate species as active intermediate, thereby revealing presence C(sp2 )-H functionalization derivatives/allylic alkylation cascade attractive catalytic transformation.

Язык: Английский

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Taming Chiral Quaternary Stereocenters via Remote H‐Bonding Stereoinduction in Palladium‐Catalyzed (3+2) Cycloadditions

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(3)

Опубликована: Ноя. 15, 2022

Ring-opening transformations of donor-acceptor (D-A) cyclopropanes enable the rapid assembly complex molecules. However, enantioselective formation chiral quaternary stereocenters using substrates bearing two different acceptors remains a challenge. Herein, we describe first palladium-catalyzed highly diastereo- and (3+2) cycloaddition vinyl electron-withdrawing groups, subset D-A cyclopropanes. The key to success this reaction is remote stereoinduction through hydrogen bond from ligands, which thereby addressed aforementioned A variety five-membered heterocycles were produced in good yields with high stereoselectivity (up 99 % yields, : 1 er >19 dr). In-depth mechanistic investigations, including control experiments theoretical calculations, revealed origin importance H-bonding stereocontrol.

Язык: Английский

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