Construction of Axially Chiral Indoles by Cycloaddition–Isomerization via Atroposelective Phosphoric Acid and Silver Sequential Catalysis

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(13), P. 8094 - 8103

Published: June 22, 2022

Axially chiral indole-based frameworks occur in natural products, bioactive molecules, and ligands. Thus, the development of catalytic asymmetric atroposelective approaches for de novo construction these is highly valuable. Here, organo/metal combined dual catalysis strategy valuable axially indole has been developed. This protocol utilized a catalyst system two phosphoric acids (1 mol %) combination with AgNO3 was based on unreported intermolecular cycloaddition–isomerization reaction our recently introduced C-alkynyl N,O-acetals 2-naphthylamines. An important class hitherto inaccessible indoles C–N axis were obtained good yields enantioselectivities. The also provided platform catalyst-controlled synthesis bearing axes, which are difficult to access by existing methods. work an example 2-naphthylamines used as 1,3-dinucleophiles three-atom (CCN) synthons cycloadditions.

Language: Английский

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Sigma-Bond Metathesis as an Unusual Asymmetric Induction Step in Rhodium-Catalyzed Enantiodivergent Synthesis of C–N Axially Chiral Biaryls

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(15), P. 8417 - 8429

Published: March 23, 2023

Mechanistic understanding of asymmetric induction plays a crucial role in designing new catalytic reactions. Reported herein is atroposelective access to C-N axially chiral isoquinolones via rhodium-catalyzed C-H activation N-alkoxy benzamides and annulation with imidoyl sulfoxonium ylides. The coupling system proceeded excellent functional group tolerance, different conditions were identified afford one or the other enantiomeric product each enantioselectivity for representative class ylide reagent, thus making both enantiomers readily available using same catalyst. Experimental computational studies revealed pathway alkylation enantio-determining formal nucleophilic substitution-C-N cyclization that mediated by rhodium catalyst σ-bond metathesis as mechanism. Computational indicated solvent-dependent enatiodivergence originated from levels neutral versus cationic species.

Language: Английский

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Recent Advances in Visible-Light-Mediated Amide Synthesis

Molecules, Journal Year: 2022, Volume and Issue: 27(2), P. 517 - 517

Published: Jan. 14, 2022

Visible-light photoredox catalysis has attracted tremendous interest within the synthetic community. As such, activation mode potentially provides a more sustainable and efficient platform for of organic molecules, enabling invention many controlled radical-involved reactions under mild conditions. In this context, amide synthesis via strategy received growing due to ubiquitous presence structural motif in numerous natural products, pharmaceuticals functionalized materials. Employing strategy, wide variety amides can be prepared effectively from halides, arenes even alkanes irradiation visible light. These methods provide robust alternative well-established strategies that involve condensation between carboxylic acid amine mediated by stoichiometric activating agent. review, representative progresses made on through light-mediated radical are summarized.

Language: Английский

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O-Allylhydroxyamine: A Bifunctional Olefin for Construction of Axially and Centrally Chiral Amino Alcohols via Asymmetric Carboamidation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(14), P. 8150 - 8162

Published: April 4, 2023

Difunctionalization of olefins offers an attractive approach to access complex chiral structures. Reported herein is the design N-protected O-allylhydroxyamines as bifunctional that undergo catalytic asymmetric 1,2-carboamidation with three classes (hetero)arenes afford amino alcohols via C-H activation. The C═C bond in O-allylhydroxyamine activated by intramolecular electrophilic amidating moiety well a migrating directing group. carboamidation reaction pattern depends on nature (hetero)arene reagent. Simple achiral reacted give centrally β-amino excellent enantioselectivity. employment axially prochiral or racemic heteroarenes afforded both axial and central chirality enantio- diastereoselectivity. In case heteroarenes, coupling follows kinetic resolution s-factor up >600. A nitrene-based mechanism has been suggested based experimental studies, unique mode induction diastereoselectivity proposed. Applications alcohol products have demonstrated.

Language: Английский

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Three-component synthesis ofN-naphthyl pyrazolesviaRh(iii)-catalyzed cascade pyrazole annulation and Satoh–Miura benzannulation

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(27), P. 4036 - 4039

Published: Jan. 1, 2023

The synthesis of N-naphthyl pyrazoles has been realized by the direct three-component reactions enaminones, aryl hydrazine hydrochlorides and internal alkynes via Rh(III) catalysis. synthetic employing simple substrates lead to simultaneous construction dual cyclic moieties, including a pyrazole ring phenyl ring, sequential formation two C-N three C-C bonds.

Language: Английский

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