Creation of a Chiral All-Carbon Quaternary Center Induced by CF₃ and CH₃ Substituents via Cu-Catalyzed Asymmetric Conjugate Addition

Organic Letters, Год журнала: 2024, Номер 26(25), С. 5312 - 5317

Опубликована: Июнь 13, 2024

Cu-catalyzed asymmetric construction of a chiral quaternary center bearing CH3 and CF3 groups was achieved with high to excellent enantioselectivity using our originally developed ligands. The conjugate addition Me3Al β-CF3-substituted enones unsaturated ketoesters proceeded efficiently. use gives optically active furanones in yields enantioselectivities. perfluoroalkyl-substituted enone does not seem be favorable the present reaction.

Язык: Английский

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Enantioselective Relay Coupling of Perfluoroalkyl and Vinylogous Ketyl Radicals

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(35)

Опубликована: Июнь 12, 2024

Abstract β‐Chiral carboxylic acids and their derivatives are highly valuable structural motifs in the fields of asymmetric synthesis medicinal chemistry. However, introduction a sterically demanding sidechain to β‐carbon, such as an all‐carbon quaternary center, remains significant challenge classical polar processes. Recently, N ‐heterocyclic carbene (NHC) mediated coupling reactions involving persistent ketyl radicals have emerged promising strategy assemble crowded carbon‐carbon bonds. Nevertheless, achieving enantioselectivity these challenging. In this work, we report our recent progress controlling for relay perfluoroalkyl vinylogous radicals. We developed chiral bifunctional NHC‐squaramide catalyst that achieves high facial selectivity critical bond‐forming event congested tertiary carbon radical radical. Chiral carboxylates bearing center at β‐position can be prepared good yield excellent enantiomeric excess. Results from density functional theory (DFT) calculations nuclear Overhauser effect (NOE) experiments indicate , N’ ‐diaryl squaramide motif adopts unusual syn ‐ conformation, enabling hydrogen bonding interactions with enolate oxygen, thereby rigidifying overall conformation transition state.

Язык: Английский

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Visible light-mediated difluoromethylation/cyclization in batch and flow: Scalable synthesis of CHF₂-containing benzimidazo- and indolo[2,1-a]isoquinolin-6(5H)-ones

Chemical Communications, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

We report here a practical and cost-effective method for the synthesis of CHF 2 -containing benzimidazo- indolo[2,1, ]-isoquinolin-6(5 H )-ones through visible light-mediated difluoromethylation/cyclization cascade.

Язык: Английский

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Visible-Light-Induced Intramolecular Radical Cyclization for the Synthesis of Benzimidazo-isoquinolineones and Pyrrolidones

Organic Letters, Год журнала: 2024, Номер 26(51), С. 11184 - 11189

Опубликована: Дек. 12, 2024

A visible-light-induced radical cyclization of α-brominated amides has been developed to construct benzimidazole[2,1-

Язык: Английский

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Understanding and Controlling Fluorinated Diacyl Peroxides and Fluoroalkyl Radicals in Alkene Fluoroalkylations

The Chemical Record, Год журнала: 2023, Номер 23(9)

Опубликована: Июль 31, 2023

Abstract The demand for practical methods the synthesis of novel fluoroalkyl molecules is increasing owing to their diverse applications. Our group has achieved efficient difunctionalizing fluoroalkylations alkenes using fluorinated carboxylic anhydrides as user‐friendly sources. Fluorinated diacyl peroxide, prepared in situ from anhydrides, enables development reactions when used a radical fluoroalkylating reagent. In this account, we aim provide an in‐depth understanding structure, bonding, and reactivity peroxides radicals well control fluoroalkylation reactions. first part physical properties are described. subsequent part, categorize into copper‐catalyzed metal‐free utilizing oxidizing peroxides. We also outline examples mechanisms.

Язык: Английский

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Visible‐Light Induced Trifluoromethylation/Cyclization of Unactivated Alkene‐Bound Quinazolinones

European Journal of Organic Chemistry, Год журнала: 2024, Номер 27(17)

Опубликована: Март 19, 2024

Abstract Herein, we reported a selective, mild method for the visible‐light‐photocatalyzed trifluoromethylation and cyclization of unactivated tethered alkenes to provide tri‐ tetracyclic quinazolinones. Trifluoroacetic acid anhydride are inexpensive readily available reagents process that proceeds without addition strong oxidant. The wide substrate scope formation 5‐ 6‐membered rings demonstrated in 44–82 % yields. Control experiments basis proposed mechanism involving photocatalyzed SET from fac ‐Ir(ppy) 3 TFAA trifluoromethyl radical‐mediated regioselective cyclization. practicality protocol was illustrated by gram‐scale synthesis 76 yield.

Язык: Английский

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Enantioselective Relay Coupling of Perfluoroalkyl and Vinylogous Ketyl Radicals

Angewandte Chemie, Год журнала: 2024, Номер 136(35)

Опубликована: Июнь 12, 2024

Abstract β‐Chiral carboxylic acids and their derivatives are highly valuable structural motifs in the fields of asymmetric synthesis medicinal chemistry. However, introduction a sterically demanding sidechain to β‐carbon, such as an all‐carbon quaternary center, remains significant challenge classical polar processes. Recently, N ‐heterocyclic carbene (NHC) mediated coupling reactions involving persistent ketyl radicals have emerged promising strategy assemble crowded carbon‐carbon bonds. Nevertheless, achieving enantioselectivity these challenging. In this work, we report our recent progress controlling for relay perfluoroalkyl vinylogous radicals. We developed chiral bifunctional NHC‐squaramide catalyst that achieves high facial selectivity critical bond‐forming event congested tertiary carbon radical radical. Chiral carboxylates bearing center at β‐position can be prepared good yield excellent enantiomeric excess. Results from density functional theory (DFT) calculations nuclear Overhauser effect (NOE) experiments indicate , N’ ‐diaryl squaramide motif adopts unusual syn ‐ conformation, enabling hydrogen bonding interactions with enolate oxygen, thereby rigidifying overall conformation transition state.

Язык: Английский

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Copper-Catalyzed Oxidative Synthesis of 3-Aryl-5-fluoroalkyl-1,3,4-oxadiazol-2(3H)-ones Using Perfluorocarboxylic Anhydride as a Reagent

The Journal of Organic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Сен. 25, 2024

A copper-catalyzed oxidative annulation of sydnones with perfluorocarboxylic anhydride for the synthesis 3-aryl-5-fluoroalkyl-1,3,4-oxadiazol-2(3

Язык: Английский

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Radical-triggered base-free 1,3-C → C migrations: chemodivergent synthesis of cyclic imines from N-allyl enamines

Organic Chemistry Frontiers, Год журнала: 2023, Номер 11(2), С. 500 - 507

Опубликована: Дек. 19, 2023

Novel radical-triggered 1,3-C → C migrations of N -allyl enamines under base-free conditions and the catalyst-dependent synthesis cyclic imines were achieved.

Язык: Английский

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Photoredox-Catalyzed Trifluoromethylation of C(sp2)–H Bonds with Trifluoroacetic Anhydride

Synfacts, Год журнала: 2023, Номер 19(07), С. 0686 - 0686

Опубликована: Июнь 16, 2023

Key words C(sp2)–H trifluoromethylation - iridium photoredox catalysis trifluoroacetic anhydride

Язык: Английский

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