Oxygen‐Linked Cyclopentadienyl Rhodium(III) Complexes‐Catalyzed Asymmetric C−H Arylation of Benzo[h]quinolines with 1‐Diazonaphthoquinones

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(28), P. 15510 - 15516

Published: April 16, 2021

Abstract Chiral cyclopentadienyl rhodium (CpRh) complex‐catalyzed asymmetric C−H functionalization reactions have witnessed a significant progress in organic synthesis. In sharp contrast, the reported chiral Cp ligands are limited to C‐linked and often synthetically challenging. To address these issues, we developed novel class of tunable bearing oxygen linkers, which were efficient catalysts for arylation benzo[ h ]quinolines with 1‐diazonaphthoquinones, affording axially heterobiaryls excellent yields enantioselectivity (up 99 % yield, 98.5:1.5 er). Mechanistic studies suggest that reaction is likely proceed by electrophilic activation, followed coupling cyclometalated rhodium(III) complex 1‐diazonaphthoquinones.

Language: Английский

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Enantioselective [3+2] Annulation of Aldimines with Alkynes by Scandium‐Catalyzed C−H Activation

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 3, 2025

Abstract The enantioselective [3+2] annulation of readily accessible aldimines with alkynes via C−H activation is, in principle, a straightforward and atom‐efficient route for synthesizing chiral 1‐aminoindenes, which are important components wide array natural products, bioactive molecules, functional materials. However, such asymmetric transformation has remained undeveloped to date due the lack suitable catalysts. Here, we report first time using half‐sandwich scandium This protocol enabled synthesis diverse multi‐substituted 1‐aminoindene derivatives 100 % atom‐efficiency, broad substrate scope, high regio‐ enantioselectivity. Density theory (DFT) analyses have revealed that noncovalent C−H⋅⋅⋅π interaction between tert ‐Bu substituent cyclopentadienyl (Cp) ligand phenyl ring an aromatic aldimine played role achieving level work not only offers efficient selective new family but also unprecedented insights into enantioselectivity control Cp‐ligated metal

Language: Английский

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Synthesis of Rigid Stepladder Polymers via Scandium-Catalyzed Polyspiroannulation of Quinoline with Alkyne

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Polymers with rigid three-dimensional architectures have attracted significant attention due to their high rigidity and intrinsic microporosity. Here, we report the synthesis of a new class stepladder polymers featuring unique spirodihydroquinoline skeletons. Under catalysis half-sandwich scandium catalyst, quinoline compounds bearing both an aryl substituent (e.g., phenyl or naphthyl) alkynyl group C≡CSiMe3) selectively undergo dearomative polyspiroannulation between skeleton alkyne unit via ortho-C–H activation group. This reaction efficiently yields comprising quaternary carbon stereocenter unprotected N–H Treatment N–H-containing alkyl lithium reagent followed by methyl iodide leads quantitative formation corresponding N-methylated polymers, which exhibit enhanced thermal stability porosity compared counterparts.

Language: Английский

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Theoretical Insights into Rare-Earth-Catalyst-Controlled Diastereo- and Enantioselective [3 + 2] Annulation of Aromatic Aldimines with Styrenes

Inorganic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 5, 2025

Rare-earth-catalyzed annulation reactions using alkenes via C–H activation offer an atom-efficient approach to constructing cyclic compounds. However, the mechanisms underlying these remain poorly understood, limiting rational design of related catalytic systems. Recently, Hou and Cong reported unprecedented example rare-earth-catalyst-controlled diastereodivergent asymmetric [3 + 2] aromatic aldimines with alkenes. To elucidate origins diastereo- enantioselectivity, density functional theory calculations were performed. The results revealed that styrene insertion step determines stereoselectivity. Styrene follows a similar metal–styrene interaction pattern across different catalysts. Specifically, during cis-insertion, interacts strongly metal center, exhibiting significant Sc···Ph interactions, whereas such interactions are absent trans-insertion. Thus, when catalyst is employed small ligand, stereoselectivity primarily governed by electronic factors, favoring cis-insertion mode. In contrast, for more sterically hindered catalyst, in insufficient overcome steric effects, leading preference trans-insertion mode, which minimizes hindrance. These findings deeper insights into catalyst-controlled enantioselectivity will also contribute stereospecific rare-earth catalysis.

Language: Английский

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Modular Access to Spiro-dihydroquinolines via Scandium-Catalyzed Dearomative Annulation of Quinolines with Alkynes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(48), P. 20462 - 20471

Published: Nov. 23, 2021

The catalytic enantioselective construction of three-dimensional molecular architectures from planar aromatics such as quinolines is great interest and importance the viewpoint both organic synthesis drug discovery, but there still exist many challenges. Here, we report scandium-catalyzed asymmetric dearomative spiro-annulation with alkynes. This protocol offers an efficient selective route for spiro-dihydroquinoline derivatives containing a quaternary carbon stereocenter unprotected N–H group readily accessible diverse alkynes, featuring high yields, enantioselectivity, 100% atom-efficiency, broad substrate scope. Experimental density functional theory studies revealed that reaction proceeded through C–H activation 2-aryl substituent in quinoline by scandium alkyl (or amido) species followed alkyne insertion into Sc–aryl bond subsequent 1,2-addition resulting alkenyl to C═N unit moiety. work opens new avenue dearomatization quinolines, leading spiro were previously difficult access other means.

Language: Английский

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Binaphthyl Scaffold: A Class of Versatile Structure in Asymmetric C–H Functionalization

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(15), P. 9359 - 9396

Published: July 18, 2022

Over the past decades, transition metal-catalyzed enantioselective C–H functionalization has emerged as a straightforward and powerful tool for rapid access to chiral molecules. The enormous advances achieved in this emerging area largely rely on development of ligands that can enable both high levels enantiocontrol efficiency. Chiral bearing binaphthyl scaffolds have been proven be versatile asymmetric due their availability, unique stereochemical features, ease fine-tuning steric electronic properties. In Review, we summarized advance applications basis scaffold functionalization.

Language: Английский

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Coordination-assisted, transition-metal-catalyzed enantioselective desymmetric C–H functionalization

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(5), P. 1458 - 1484

Published: Jan. 1, 2022

Recent advances in transition-metal-catalyzed enantioselective desymmetric C–H functionalization are summarized.

Language: Английский

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Access to Planar Chiral Ferrocenes via N-Heterocyclic Carbene-Catalyzed Enantioselective Desymmetrization Reactions

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(4), P. 2706 - 2713

Published: Feb. 9, 2022

Ferrocene-derived dicarbaldehydes bearing pro-chiral planes are desymmetrized under the catalysis of chiral N-heterocyclic carbene organic catalysts. The reaction features selective activation and one aldehyde moieties ferrocene derivative while leaving other unit untouched. Our affords enantiomerically enriched planar products obtained that amenable for further transformations. Preliminary application studies show encouraging results when our explored in chemical synthesis antimicrobial utilities pesticide development.

Language: Английский

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Chiral Bidentate Boryl Ligand-Enabled Iridium-Catalyzed Enantioselective Dual C–H Borylation of Ferrocenes: Reaction Development and Mechanistic Insights

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(3), P. 1830 - 1840

Published: Jan. 19, 2022

Ferrocenes with planar chirality are an important class of privileged scaffolds for diverse chiral ligands and organocatalysts. The development efficient catalytic asymmetric methods under mild reaction conditions is a long-sought goal in this field. Though many transition-metal-catalyzed C–H activation have been recorded during the last decade, most them related to C–C bond-forming reactions. Owing useful attribute C–B bond, we herein report amide-directed iridium-catalyzed enantioselective dual borylation ferrocenes. key success transformation relies on bidentate boryl ligand judicious choice directing group. current could tolerate vast array functionalities, affording variety borylated ferrocenes good excellent enantioselectivities (35 examples, up 98% enantiomeric excess). We also demonstrated synthetic utility by preparative-scale transformations product. Finally, basis observed experimental data, performed DFT calculations understand its pathway induction, which reveals that methyl C(sp3)-H crucial conferring high enantioselectivity through amplified steric effect caused interacted B–O fragment transition state.

Language: Английский

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Copper-catalyzed asymmetric C(sp2)–H arylation for the synthesis of P- and axially chiral phosphorus compounds

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 20, 2023

Transition metal-catalyzed C-H bond functionalization is an important method in organic synthesis, but the development of methods that are lower cost and have a less environmental impact desirable. Here, Cu-catalyzed asymmetric C(sp

Language: Английский

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