Recent Advances in Rare‐Earth Metal‐Catalyzed C−H Functionalization Reactions

ChemCatChem, Journal Year: 2022, Volume and Issue: 14(23)

Published: Oct. 12, 2022

Abstract There has been a persistent impetus for the development of versatile C−H functionalization reactions, which represents powerful approach to wide variety valuable chemical compounds. Transition metal catalyzed attracted intense interest and witnessed considerable advances in this field owing its outstanding regioselectivity atom‐economy. In recent years, rare‐earth (RE) metal‐based catalysts have successfully employed flourished area, demonstrating unique selectivity complementary reactivity with respect late‐transition metal‐catalyzed functionalization. The by taking advantage these characteristic properties is great importance interest. Herein, panorama during last decade presented.

Language: Английский

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Yttrium‐Catalyzed ortho‐Selective C−H Borylation of Pyridines with Pinacolborane

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(21)

Published: March 9, 2022

This work reports a site-selective C-H borylation of pyridines at the ortho-position with pinacolborane enabled by an yttrocene catalyst. The reaction provides new family 2-pyridyl boronates broad substrate scope and high atom efficiency. resultant were able to undergo variety transformations, e.g., oxidation, Suzuki-Miyaura coupling, Chan-Lam amination etherification. Catalytic intermediates, including ortho-C-H metalated borylated complexes, isolated from stoichiometric experiments confirmed single-crystal X-ray diffraction.

Language: Английский

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Divergent Synthesis of Multi‐Substituted Aminotetralins via [4+2] Annulation of Aldimines with Alkenes by Rare‐Earth‐Catalyzed Benzylic C(sp³)−H Activation

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(13)

Published: Jan. 16, 2024

The search for efficient and selective methods the divergent synthesis of multi-substituted aminotetralins is much interest importance. We report herein first time diastereoselective [4+2] annulation 2-methyl aromatic aldimines with alkenes via benzylic C(sp

Language: Английский

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Elucidating the mechanism and origin of diastereoselectivity in scandium-catalyzed β-C(sp³)–H activation and transformation of an aliphatic aldimine

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(16), P. 4391 - 4401

Published: Jan. 1, 2024

The mechanism and origin of regio- diastereoselectivity in the reaction divergent [3 + 2] annulation aliphatic aldimines with alkenes by scandium-catalyzed β-C(sp 3 )–H activation have been revealed detail using DFT calculations.

Language: Английский

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(Z)-Selective Isomerization of 1,1-Disubstituted Alkenes by Scandium-Catalyzed Allylic C–H Activation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(39), P. 26766 - 26776

Published: Sept. 20, 2024

The isomerization of 1,1-disubstituted alkenes through 1,3-hydrogen shift is an atom-efficient route for synthesizing trisubstituted alkenes, which are important moieties in many natural products, pharmaceuticals, and organic materials. However, this reaction often encounters regio- stereoselectivity challenges, typically yielding

Language: Английский

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Enantioselective Synthesis of 1-Aminoindanes via [3 + 2] Annulation of Aldimines with Alkenes by Scandium-Catalyzed C–H Activation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(31), P. 17468 - 17477

Published: July 28, 2023

Multisubstituted chiral 1-aminoindanes are important components in many pharmaceuticals and bioactive molecules. Therefore, the development of efficient selective methods for synthesis is great interest importance. In principle, asymmetric [3 + 2] annulation aldimines with alkenes through C–H activation most atom-efficient straightforward route construction 1-aminoindanes, but such a transformation has remained undeveloped to date probably due lack suitable catalysts. Herein, we report first time enantioselective wide range aromatic via ortho-C(sp2)–H by half-sandwich scandium catalysts, which provides multisubstituted 1-aminoindanes. This protocol features 100% atom-efficiency, broad functional group compatibility, high regio-, diastereo-, enantioselectivity (up >19:1 dr 99:1 er). Remarkably, fine-tuning sterics ligand around catalyst metal center, diastereodivergent styrenes been achieved level diastereo- enantioselectivity, offering an method both trans cis diastereomers novel class 1-aminoindane derivatives containing two contiguous stereocenters from same set starting materials. Moreover, aliphatic α-olefins, norbornene, 1,3-dienes also achieved.

Language: Английский

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Switchable, Reagent‐Controlled Diastereodivergent Photocatalytic Carbocyclisation of Imine‐Derived α‐Amino Radicals

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(45), P. 24116 - 24123

Published: Aug. 27, 2021

A reagent-controlled stereodivergent carbocyclisation of aryl aldimine-derived, photocatalytically generated, α-amino radicals possessing adjacent conjugated alkenes, affording either bicyclic or tetracyclic products, is described. Under net reductive conditions using commercial Hantzsch ester, the radical species underwent a single stereoselective cyclisation to give trans-configured amino-indane structures in good yield, whereas substituted ester as milder reductant afforded cis-fused tetrahydroquinoline frameworks, resulting from two consecutive cyclisations. Judicious choice reaction allowed libraries both and dual products be synthesised with high selectivity, notable predictability, good-to-excellent yields. Computational analysis employing DFT revealed pathway mechanistic rationale behind this finely balanced yet readily controlled photocatalytic system.

Language: Английский

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NHC-catalysed retro-aldol/aldol cascade reaction enabling solvent-controlled stereodivergent synthesis of spirooxindoles

Chinese Chemical Letters, Journal Year: 2021, Volume and Issue: 32(8), P. 2567 - 2571

Published: March 7, 2021

Language: Английский

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Regio‐ and Diastereoselective [3+2] Annulation of Aliphatic Aldimines with Alkenes by Scandium‐Catalyzed β‐C(sp³)−H Activation

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 61(7)

Published: Dec. 15, 2021

Here we report for the first time regio- and diastereoselective [3+2] annulation of a wide range aliphatic aldimines with alkenes via activation an unactivated β-C(sp3 )-H bond by half-sandwich scandium catalysts. This protocol offers straightforward atom-efficient route synthesis new family multi-substituted aminocyclopentane derivatives from easily accessible alkenes. The styrenes exclusively afforded 5-aryl-trans-substituted 1-aminocyclopentane excellent diastereoselectivity through 2,1-insertion styrene unit. selectively gave 4-alkyl-trans-substituted products in 1,2-insertion fashion. A catalytic amount appropriate amine such as adamantylamine (AdNH2 ) or dibenzylamine (Bn2 NH) showed significant effects on catalyst activity stereoselectivity.

Language: Английский

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Regio‐ and Diastereoselective Formal [2+2] Cycloaddition of Allenes with Amino‐Functionalized Alkenes by Rare‐Earth‐Catalyzed C(sp²)−H Activation

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(45)

Published: Sept. 19, 2022

The [2+2] cycloaddition of allenes with alkenes is much interest and importance as a straightforward route for the construction four-membered carbocycles but has remained underexplored to date. Herein we report first time intermolecular regio- diastereoselective formal wide range amino-functionalized by half-sandwich rare-earth catalysts. reaction proceeded through an allene C(sp2 )-H activation mechanism initiated site-selective deprotonation unit metal alkyl species followed alkene insertion into resulting metal-allenyl bond subsequent intramolecular C=C bond. This protocol offers unique synthesis new family cyclobutane cyclobutene derivatives which were difficult access previously.

Language: Английский

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