Mechanistic Study of Ni and Cu Dual Catalyst for Asymmetric C–C Bond Formation; Asymmetric Coupling of 1,3-Dienes with C-nucleophiles to Construct Vicinal Stereocenters

ACS Catalysis, Год журнала: 2021, Номер 11(11), С. 6643 - 6655

Опубликована: Май 21, 2021

We report details of the reaction mechanism for a coupling 1,3-dienes with C-nucleophiles that was catalyzed by Ni/Cu cooperative catalyst system using Ni(cod)2 and [Cu(CH3CN)4]PF6 in presence chiral JOSIPHOS-type bisphosphine ligand iPr2NEt, providing direct access to highly valuable vicinal quaternary tertiary stereocenters high enantio- diastereoselectivity. The bimetallic exhibited broad substrate scope, including both cyclic/acyclic stabilized nucleophiles aryl-/alkyl-substituted 1,3-dienes. elucidated depth isolating characterizing four key complexes nickel copper conducting deuterium labeling experiments, kinetic studies, density functional theory calculations. turnover-limiting step this is proton-transfer diene-coordinated Ni complex 6 from cationic Cu 8 yield π-allyl 7 enolate 9, respectively. stereoselectivity also clarified according single-point calculations intermediates 9.

Язык: Английский

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Asymmetric transformations enabled by synergistic dual transition-metal catalysis

Chem Catalysis, Год журнала: 2022, Номер 3(1), С. 100455 - 100455

Опубликована: Ноя. 17, 2022

Язык: Английский

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Cooperative Catalyst‐Enabled Regio‐ and Stereodivergent Synthesis of α‐Quaternary α‐Amino Acids via Asymmetric Allylic Alkylation of Aldimine Esters with Racemic Allylic Alcohols

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(46)

Опубликована: Сен. 26, 2022

We describe cooperative bimetallic catalysis that enables regio-/stereodivergent asymmetric α-allylations of aldimine esters. By employing Et3 B as the key activator, racemic allylic alcohols can be directly ionized to form Pd or Ir-π-allyl species in presence achiral chiral Ir complexes, respectively. The less more substituted termini metal-π-allyl are amenable nucleophilic attack by Cu-azomethine ylide, formation which is simultaneously facilitated B, affording α-quaternary α-amino acids with high regioselectivity and excellent stereoselectivity. use readily available electrophilic precursors represents an improvement from environmental atom/step economy perspective. Computational mechanistic studies reveal crucial role additive origins stereo- regioselectivities analyzing steric effects, dispersion interactions, frontier orbital population.

Язык: Английский

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Stereodivergent Synthesis of α-Quaternary Serine and Cysteine Derivatives Containing Two Contiguous Stereogenic Centers via Synergistic Cu/Ir Catalysis

Organic Letters, Год журнала: 2020, Номер 22(12), С. 4852 - 4857

Опубликована: Июнь 6, 2020

A stereodivergent preparation of α-quaternary serine/cysteine derivatives incorporating two adjacent stereogenic centers has been developed through Cu/Ir-catalyzed asymmetric allylation 2-oxazoline-4-carboxylates and 2-thiazoline-4-carboxylates. Tuning the electronic effect is key to enhancing reactivity suppressing undesired β-elimination. The salient feature this protocol that all four stereoisomers serine cysteine could be achieved from identical starting materials pairwise combination distinct chiral catalysts.

Язык: Английский

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Synergistic Catalysis with Azomethine Ylides

Chinese Journal of Chemistry, Год журнала: 2020, Номер 39(1), С. 15 - 24

Опубликована: Июль 29, 2020

Abstract Azomethine ylides are useful intermediates for the rapid construction of chiral N‐ containing compounds. However, its synthetic potential has not been fully developed due to limited reaction models. In combination with synergistic catalysis and azomethine ylide chemistry, we have several types novel catalytic system including Cu/Pd, Cu/Ir PTC/Ir catalysis, which can convert readily‐available various high‐valued molecules such as unnatural α‐amino acids, homoallylic amines heterocycles. Compared traditional mono‐catalysis, catalyst exhibits enhanced efficiency induction ability in many cases. addition, demonstrated that these strategies could be applied bioactive compounds natural products.

Язык: Английский

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Synergistic Pd/Cu catalysis for stereoselective allylation of vinylethylene carbonates with glycine iminoesters: Enantioselective access to diverse trisubstituted allylic amino acid derivatives

Green Synthesis and Catalysis, Год журнала: 2021, Номер 2(2), С. 228 - 232

Опубликована: Апрель 19, 2021

We reported a synergistic Pd/Cu catalyzed enantioselective decarboxylative allylation of vinylethylene carbonates with glycine iminoesters, which provides facile access to non-proteinogenic diverse trisubstituted allylic amino acid derivatives in high yields, exclusive regioselectivities and excellent stereoselectivities. This reaction tolerates wide range γ β-aryl substituted either electron-donating or electron-withdrawing groups. Significantly, this method was proven be sufficient the gram scale synthesis chiral while retaining enantioselectivity geometric control.

Язык: Английский

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Synergistic catalysis for stereocontrol of prochiral nucleophiles in palladium-catalyzed asymmetric allylic substitution

Science China Chemistry, Год журнала: 2023, Номер 66(8), С. 2238 - 2255

Опубликована: Июль 20, 2023

Язык: Английский

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Synergistic Cu/Pd‐Catalyzed Asymmetric Allenylic Alkylation of Azomethine Ylides for the Construction of α‐Allene‐Substituted Nonproteinogenic α‐Amino Acids

Chemistry - A European Journal, Год журнала: 2019, Номер 25(37), С. 8681 - 8685

Опубликована: Май 6, 2019

An unprecedented asymmetric allenylic alkylation of readily available imine esters, which was enabled by a synergistic Cu/Pd catalysis, has been developed. This dual catalytic system possesses good substrate compatibility, delivering diverse array nonproteinogenic α-allenylic α-mono- or α,α-disubstituted α-amino acids (α-AAs) with high yields and generally excellent enantioselectivities. Furthermore, the scalability practicability current synthetic protocol were proven performing gram-scale reactions first synthesis naturally occurring (S)-γ-allenic acid, respectively.

Язык: Английский

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Synergistic Cu/Pd Catalysis for Enantioselective Allylation of Ketimine Esters: The Direct Synthesis of α‐Substituted α‐Amino Acids and 2H‐Pyrrols

Advanced Synthesis & Catalysis, Год журнала: 2018, Номер 360(24), С. 4715 - 4719

Опубликована: Окт. 6, 2018

Abstract An efficient synergistic Cu/Pd catalyzed enantioselective α‐allylation of acyclic ketimine esters has been reported, which provides an entry to nonproteinogenic α‐allyl α‐amino acids in high yield, exclusive regioselectivity, and excellent enantioselectivity. Moreover, the more challenging cyclic ester could also be employed as a nucleophile for construction 3,4‐dihydro‐2 H‐ pyrrole derivatives bearing quaternary stereogenic center using same catalytic system. magnified image

Язык: Английский

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Enantioselective and Diastereodivergent Access to α‐Substituted α‐Amino Acids via Dual Iridium and Copper Catalysis

Advanced Synthesis & Catalysis, Год журнала: 2018, Номер 361(5), С. 1130 - 1139

Опубликована: Окт. 24, 2018

Abstract The work reported within this paper describes an example of the application bimetallic catalysts system in allylic substitution reactions. development new nucleophiles and control enantio‐ diastereoselectivity are main research topics area. An improvement reactivity has been realized for dual Ir/Cu catalyzed alkylation inactive prochiral nucleophiles, under mild reaction conditions. Furthermore, choice metallacyclic iridium complex chiral Cu‐Phox combination allows access to all four stereoisomers from same starting materials with excellent enantioselectivity (up >99% ee >20:1 dr). Significantly, method provides a stereodivergent 2‐amino‐3‐methylpent‐4‐acid ester, important fragment synthesis Halipeptin A. magnified image

Язык: Английский

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