B(C₆F₅)₃-Catalyzed Dehydrogenation of Pyrrolidines to Form Pyrroles

ACS Catalysis, Год журнала: 2024, Номер 14(7), С. 4856 - 4864

Опубликована: Март 18, 2024

Pyrroles are important N-heterocycles found in medicines and materials. The formation of pyrroles from widely accessible pyrrolidines is a potentially attractive strategy but an underdeveloped approach due to the sensitivity oxidative conditions required achieve such transformation. Herein, we report catalytic that employs commercially available B(C6F5)3 operationally simple procedure allows serve as direct synthons for pyrroles. Mechanistic studies have revealed insights into borane-catalyzed dehydrogenative processes.

Язык: Английский

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Dual Relay Rh-/Pd-Catalysis Enables β-C(sp3)-H Arylation of α-Substituted Amines

Chemical Science, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

A dual relay catalytic protocol, built on reversible dehydrogenation of amines by Rh catalysis and C-H functionalisation transient imines Pd catalysis, is reported to enable regioselective arylation at their unactivated β-C(sp3)-H bond. Notably, the new strategy applicable secondary anilines N-PMP-protected primary aliphatic intermediate steric demands, which in contrast existing strategies that involve either free-amine-directed activation for highly sterically hindered or steric-controlled migrative cross-coupling unhindered N-Boc protected amines. Regioselectivity reaction imposed electronic effects imine intermediates rather than between specific starting materials catalysts, thereby opening uncharted scope In a broader sense, this study demonstrates opportunities involving hydrogen borrowing chemistry, previously explored alcohols, execute otherwise challenging transformations amines, commonly present natural products, pharmaceuticals, biologically active molecules, functional materials.

Язык: Английский

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Lewis Acid‐Driven Inverse Hydride Shuttle Catalysis

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(27)

Опубликована: Март 29, 2024

Abstract Inverse hydride shuttle catalysis provides a multicomponent platform for the highly efficient synthesis of alkaloid frameworks with exquisite diastereoselectivity. However, number limitations hinder this method, primarily strict requirement electron‐deficient acceptors. Herein, we present general Lewis acid‐driven approach to address constraint, and have developed two broad strategies enabling modular complex azabicycles that were entirely unattainable using previous method. The enhanced synthetic flexibility facilitates streamlined asymmetric cyclization, leading concise total (−)‐tashiromine.

Язык: Английский

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B(C₆F₅)₃-Catalyzed C(sp³)–H Alkylation of Tertiary Amines with Electron-Deficient Olefins: Determinants of Site Selectivity

ACS Catalysis, Год журнала: 2024, Номер 14(10), С. 8041 - 8049

Опубликована: Май 8, 2024

The reason for the site selectivity previously reported B(C6F5)3-catalyzed C(sp3)–H alkylation of tertiary amines with electron-deficient olefins remains a mystery. appears to be governed by number electron-withdrawing groups (EWGs) on olefin: one EWG results in α-alkylation, whereas two EWGs (one each end double bond) result β-alkylation. In this study, we solved mystery and unlocked pathway β-alkylation bearing only EWG. Control experiments density functional theory calculations provided detailed picture reaction mechanism both α- Furthermore, demonstrated broad scope reaction.

Язык: Английский

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Site‐Selective Distal C(sp3)–H Bromination of Aliphatic Amines as a Gateway for Forging Nitrogen‐Containing sp3 Architectures

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Май 21, 2024

Herein, we disclose a new strategy that rapidly and reliably incorporates bromine atoms at distal, secondary C(sp

Язык: Английский

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Hydride Shuttle Catalysis: From Conventional to Inverse Mode

JACS Au, Год журнала: 2024, Номер 4(9), С. 3358 - 3369

Опубликована: Авг. 19, 2024

Hydride shuttle catalysis has emerged as a powerful synthetic platform, enabling the selective formation of C–C bonds to yield sp3-rich structures. By virtue compelling reactivity sterically encumbered Lewis acids from frustrated pair regime, hydride enables regioselective functionalization alkyl amines at either α- or β-position. In contrast classical acid reactivity, increased steric hindrance prevents interaction with basic amine itself, instead leading reversible abstraction α-carbon. The created positive charge facilitates occurrence transformations before rebound similar capture event happen. this Perspective, we outline broad selection featuring catalysis, well recently developed approach inverse catalysis. Both strategies give rise wide array functionalized and offer elegant approaches otherwise elusive bond formations.

Язык: Английский

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Lewis Säure‐Getriebene Inverse Hydrid‐Shuttle Katalyse

Angewandte Chemie, Год журнала: 2024, Номер 136(27)

Опубликована: Март 29, 2024

Abstract Inverse Hydrid‐Shuttle Katalyse bildet eine Plattform für die hocheffiziente und diastereoselektive Synthese von Alkaloidstrukturen durch Multikomponentenreaktionen. Mehrere Einschränkungen hindern jedoch breite Anwendbarkeit dieses Ansatzes, darunter vor allem Notwendigkeit nach besonders elektronenarmen Akzeptoren. Hier präsentieren wir einen allgemeinen, Lewis Säuren getriebenen Ansatz, um diese Einschränkung anzugehen, haben zwei Strategien entwickelt, modulare komplexer azabicyclischer Systeme ermöglichen, mit der früheren Methode unerreichbar waren. Die so gewonnene synthetische Flexibilität führt zu einer verbesserten asymmetrischen Cyclisierung, kurze Totalsynthese des Alkaloids (−)‐Tashiromin ermöglicht hat.

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Site‐Selective Distal C(sp3)–H Bromination of Aliphatic Amines as a Gateway for Forging Nitrogen‐Containing sp3 Architectures

Angewandte Chemie, Год журнала: 2024, Номер unknown

Опубликована: Май 21, 2024

Abstract Herein, we disclose a new strategy that rapidly and reliably incorporates bromine atoms at distal, secondary C(sp 3 )−H sites in aliphatic amines with an excellent predictable site‐selectivity pattern. The resulting halogenated building blocks serve as versatile linchpins to enable series of carbon‐carbon carbon‐heteroatom bond‐formations remote ) sites, thus offering modular unified platform expediates the access advanced sp architectures possessing valuable nitrogen‐containing saturated heterocycles interest medicinal chemistry settings.

Язык: Английский

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Enantioselective Vinylogous Addition of Enones to Allenes Enabled by Synergistic Borane/Palladium Catalysis

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Дек. 24, 2024

Herein, we report a method for enantioselective vinylogous addition of enones to alkoxyallenes enabled by synergistic borane/palladium catalysis. The inductive effect provided borane coordination the ketone was essential closing gap between conditions needed generation dienolate and those initiation palladium catalytic cycle protonation metal catalyst. Furthermore, accomplished first example stereodivergent synthesis with chiral borane/transition-metal catalysts.

Язык: Английский

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