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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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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β‐C−H Allylation of Trialkylamines with Allenes Promoted by Synergistic Borane/Palladium Catalysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(5)

Опубликована: Дек. 14, 2023

Functionalization of the C(sp

Язык: Английский

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Accessing Highly Substituted Indoles via B(C₆F₅)₃-Catalyzed Secondary Alkyl Group Transfer

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(6), С. 4244 - 4248

Опубликована: Фев. 23, 2024

Herein, we report a synthetic method to access range of highly substituted indoles via the B(C6F5)3-catalyzed transfer 2° alkyl groups from amines. The transition-metal-free catalytic approach has been demonstrated across broad and amine donors, including various substituents on both reacting components, useful C(3)-alkylated indole products. process can be performed using Schlenk line techniques in combination with commercially available B(C6F5)3·nH2O solvents, which obviates requirement for specialized equipment (e.g., glovebox).

Язык: Английский

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Recent Advances in Catalysis Using Organoborane-Mediated Hydride Abstraction

Synlett, Год журнала: 2023, Номер 34(18), С. 2117 - 2128

Опубликована: Июнь 16, 2023

Abstract C–H functionalization is widely regarded as an important area in the development of synthetic methodology, enabling design more time- and atom-efficient syntheses. The ability electron-deficient organoboranes to mediate hydride abstraction from α-amino bonds therefore great interest, reactive iminium hydridoborate moieties generated are able participate a range synthetically useful transformations. In this review, we cover recent advances made organoborane-mediated abstraction, focus on catalytic applications boranes α- or β-functionalization, α,β-difunctionalization, dehydrogenation amines. 1 Introduction 2 α-Functionalization Amines 3 β-Functionalization 4 α,β-Difunctionalization 5 Dehydrogenation 6 Summary Future Prospects

Язык: Английский

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Enantioselective Alkynylation of 2‐Aryl‐3H‐indol‐3‐ones via Cooperative Catalysis of Copper/Chiral Phosphoric Acid

Chemistry - An Asian Journal, Год журнала: 2023, Номер 18(18)

Опубликована: Авг. 2, 2023

Abstract A facile enantioselective alkynylation of cyclic ketimines attached to a neutral functional group utilizing the dual Cu(I)‐CPA catalysis is described. The strategy 2‐aryl‐3 H ‐indol‐3‐one directly chiral propargylic amines containing indolin‐3‐one moiety in good yields and enantioselectivities. Moreover, gram‐scale synthesis propargylamines based C2‐quaternary indolin‐3‐ones was performed. synthetic applications were confirmed by transformations products with no decrease yield enantioselectivity.

Язык: Английский

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Dihydropyrrole-3-thiones: one-pot synthesis from propargylamines, acyl chlorides and sodium sulfide

Organic & Biomolecular Chemistry, Год журнала: 2023, Номер 21(34), С. 6903 - 6913

Опубликована: Янв. 1, 2023

A one-pot synthesis of 1,2,5-trisubstituted-1,2-dihydro-3 H -pyrrole-3-thiones (up to 91% yield) by the successive treatment available propargylamines with acyl chlorides (PdCl 2 /CuI/Ph 3 P/Et N, toluene, 40–45 °C, h) and sodium sulfide (Na S·9H O, EtOH, 20–25 7 has been developed.

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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Gold‐Catalysed 1,2‐Difunctionalisation: Sulfoximines as N‐ and O‐Transfer Reagents

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

Опубликована: Дек. 11, 2024

Abstract Among the nucleophilic oxidants employed in gold‐catalysed oxidation of alkynes, sulphur‐based reagents have played a substantial role since beginning, granting access to respective gold carbene intermediates. Herein, we describe first example substance class sulfoximines being used as atom transfer alkynes catalysis. Based on transformation N ‐(2‐alkynylphenyl) 3 H ‐indol‐3‐ones, it is demonstrated that sulfoximine functionality capable selectively transferring its nitrogen moiety alkyne, forming α‐imino carbene, which then oxidised by released sulfoxide second step via pseudo‐intramolecular mechanism—a distinctive feature differentiates this work mechanistically from earlier studies. A combination extensive experimental and theoretical studies provides evidence for mechanistic rationale. As no external 1,2‐difunctionalisation alkyne unit are required, wide variety functional groups tolerated transformation, affording desired ‐indol‐3‐ones mostly good yields. It was further also showcased possible combine our methodology with additional transformations ‐indol‐3‐one core one‐pot procedures, allowing facile C2‐quaternary indolin‐3‐one structures.

Язык: Английский

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β‐C−H Allylation of Trialkylamines with Allenes Promoted by Synergistic Borane/Palladium Catalysis

Angewandte Chemie, Год журнала: 2023, Номер 136(5)

Опубликована: Дек. 14, 2023

Abstract Functionalization of the C(sp 3 )−H bonds trialkylamines is challenging, especially for reactions at positions other than α position. Herein, we report a method β‐C(sp allylation trialkylamines. In these reactions, which involve synergistic borane/palladium catalysis, an enamine intermediate first generated from amine via α,β‐dehydrogenation promoted by B(C 6 F 5 ) and base, then undergoes palladium‐catalyzed reaction with allene to give product. Because hydride proton resulting initial dehydrogenation are ultimately shuttled product palladium catalyst, respectively, show excellent atom economy. The establishment this paves way future studies C−H functionalization means borane/transition‐metal catalysis.

Язык: Английский

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