Dual-Catalyzed Stereodivergent Electrooxidative Homocoupling of Benzoxazolyl Acetate

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(2), С. 1522 - 1531

Опубликована: Янв. 3, 2024

The development of a reliable strategy for stereodivergent radical reactions that allows convenient access to all stereoisomers homocoupling adducts with multiple stereogenic centers remains an unmet goal in organic synthesis. Herein, we describe dual-catalyzed electrooxidative C(sp3)–H/C(sp3)–H complete absolute and relative stereocontrol the synthesis molecules contiguous quaternary stereocenters general predictable manner. reaction is achieved by synergistically utilizing two distinct chiral catalysts convert identical racemic substrates into inherently distinctive reactive intermediates, dictate enantioselective addition, allow full complement stereoisomeric products via simple catalyst permutation. successful execution dual-electrocatalytic programmed activation provides significant conceptual advantage will serve as useful foundation further research cooperative stereocontrolled transformations diversity-oriented

Язык: Английский

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Synergistic Pd/Cu-Catalyzed 1,5-Double Chiral Inductions

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(13), С. 9241 - 9251

Опубликована: Март 19, 2024

Much attention has been focused on the catalytic asymmetric creation of single chiral centers or two adjacent stereocenters. However, construction nonadjacent stereocenters is significant importance but challenging because lack remote induction models. Herein, based a C═C bond relay strategy, we report synergistic Pd/Cu-catalyzed 1,5-double model. All four stereoisomers target products bearing 1,5-nonadjacent involving both allenyl axial and central chirality could be obtained divergently by simply changing combination catalysts with different configurations. Control experiments DFT calculations reveal novel mechanism 1,5-oxidative addition, contra-thermodynamic η3-allyl palladium shift, conjugate nucleophilic substitution, which play crucial roles in control reactivity, regio-, enantio-, diastereoselectivity. It expected that this strategy may provide general protocol for synthesis structural motifs distant

Язык: Английский

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Interrupting Associative π–σ–π Isomerization Enables Z-Retentive Asymmetric Tsuji–Trost Reaction

Journal of the American Chemical Society, Год журнала: 2025, Номер 147(3), С. 2776 - 2785

Опубликована: Янв. 8, 2025

The asymmetric Tsuji-Trost reaction has been extensively studied due to its importance in establishing stereogenic centers, often adjacent an E-olefin moiety organic molecules. generally preferential formation of chiral products is believed result from the thermodynamically more stable syn-π-allylpalladium intermediate. rapid associative π-σ-π isomerization makes it challenging synthesize Z-olefin via transient anti-π-allylpalladium Herein, we report a strategy for regulating by tuning steric bulkiness ligands, allylic leaving groups, and counteranions. utilization Pd catalyst derived phosphoramidite ligands interrupts isomerization, enabling highly efficient Z-retentive toward array α-amino acid derivatives bearing motif high yields (up 95%) excellent stereoselectivity 99% ee >19:1 Z/E) with low loading (0.1 mol %). mechanistic insights design reported this work pave way rational developments Tsuji-Trost-type reactions.

Язык: Английский

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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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Stereodivergent Construction of Csp³−Csp³Bonds Bearing Vicinal Stereocenters by Synergistic Palladium and Phase‐Transfer Catalysis

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(2)

Опубликована: Ноя. 16, 2022

Abstract Synergistic catalysis has emerged as one of the most powerful tools for stereodivergent formation Csp 3 −Csp bonds bearing vicinal stereocenters. Despite many successes that have been achieved in this field, coupling reactions involving stabilized nucleophiles remain challenging because competing single‐catalysis pathway. Herein, we report a synergistic palladium/phase‐transfer catalyst system enables diastereodivergent 1,3‐dienes with nucleophile oxindoles. Both syn and anti products, quaternary tertiary stereocenters, could be selectively produced good yields high enantio‐ diastereoselectivities. Non‐covalent activation via chiral ion pair biphasic is crucial success factor achieving diastereodivergence.

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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Simultaneous Dual Cu/Ir Catalysis: Stereodivergent Synthesis of Chiral β-Lactams with Adjacent Tertiary/Quaternary/Tertiary Stereocenters

ACS Catalysis, Год журнала: 2023, Номер 13(4), С. 2555 - 2564

Опубликована: Фев. 6, 2023

A stereodivergent synthesis of chiral β-lactams with contiguous tertiary/quaternary/tertiary stereocenters has been achieved by a Cu/Ir-catalyzed three-component interrupted Kinugasa allylic alkylation reaction. The two catalysts independently exert high local stereocontrol, providing access to four the eight possible stereoisomers in yields >99% ee. features this strategy are asymmetric simultaneous dual metal-catalyzed cascade reactions stereoselective coupling highly transient organometallic intermediates.

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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Stereodivergent asymmetric hydrogenation of quinoxalines

Chem, Год журнала: 2023, Номер 9(9), С. 2585 - 2600

Опубликована: Май 31, 2023

Язык: Английский

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