Rhodium-Catalyzed Dehydrogenative Annulation of N-Arylmethanimines with Vinylene Carbonate for Synthesizing Quinolines

Organic Letters, Год журнала: 2021, Номер 23(21), С. 8527 - 8532

Опубликована: Окт. 20, 2021

Here we report a novel Rh-catalyzed C−H/C−H alkenylation of N-arylmethanimines with vinylene carbonate acting as unit. Forty examples C3,C4-nonsubstituted quinolines were achieved from commercially available starting materials. This identified process features an exceedingly simple system, lower loading catalyst, and the capacity for postfunctionalization bioactive molecules.

Язык: Английский

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Recent progress in rare-earth metal-catalyzed sp² and sp³ C–H functionalization to construct C–C and C–heteroelement bonds

Organic Chemistry Frontiers, Год журнала: 2022, Номер 9(11), С. 3102 - 3141

Опубликована: Янв. 1, 2022

The review presents rare-earth metal-catalyzed C(sp 2 /sp 3 )–H functionalization accessing C–C/C–heteroatom bonds and olefin (co)polymerization, highlighting substrate scope, mechanistic realization, origin of site-, enantio-/diastereo-selectivity.

Язык: Английский

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

ChemCatChem, Год журнала: 2022, Номер 14(23)

Опубликована: Окт. 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.

Язык: Английский

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

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(21)

Опубликована: Март 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.

Язык: 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, Год журнала: 2024, Номер 146(39), С. 26766 - 26776

Опубликована: Сен. 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

Язык: Английский

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Mechanisms and Origins of Regioselectivity in Rare-Earth-Catalyzed C–H Functionalization of Anisoles and Thioanisoles

Inorganic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 12, 2025

The direct catalytic C–H functionalization of aromatic compounds such as anisoles and thioanisoles is great interest significance. However, achieving precise regioselectivity remains a major challenge. In this study, we conducted comprehensive density functional theory calculations to explore the mechanisms rare-earth-catalyzed regioselective alkylation, borylation, silylation anisole thioanisole. results reveal that in cationic alkylation systems, alkene insertion step follows substrate-assisted mechanism, which an additional substrate molecule acts ligand facilitate transformation. neutral borylation although mononuclear hydride species readily dimerize into binuclear due thermodynamic stability, process predominantly proceeds via pathway. Furthermore, origins were thoroughly elucidated. A detailed analysis electronic steric effects related transition states reveals that, for anisole, primarily governed by ring strain. Since α-C(sp3)–H activation involves formation highly strained three-membered ring, reaction preferentially occurs at ortho-C(sp2)–H site, forming less four-membered ring. contrast, thioanisole, play decisive role, driving more negatively charged α-C(sp3) site stronger metal–carbon interactions.

Язык: Английский

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Solvent-Switched Manganese(I)-Catalyzed Regiodivergent Distal vs Proximal C–H Alkylation of Imidazopyridine with Maleimide

Organic Letters, Год журнала: 2021, Номер 23(19), С. 7370 - 7375

Опубликована: Сен. 20, 2021

A sustainable Mn(I)-catalyzed exclusive solvent-dependent functionalization of imidazopyridine with maleimide via an electrophilic metalation at the distal (in 2,2,2-trifluoroethanol (TFE)) and chelation assisted proximal tetrahydrofuran (THF)) has been developed. The strategy was successfully applied to drug Zolimidine a broad range substrates, thereby reflecting method's versatility.

Язык: 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, Год журнала: 2023, Номер 145(31), С. 17468 - 17477

Опубликована: Июль 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.

Язык: Английский

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Unveiling the Detailed Mechanism and Origins of Chemo-, Regio-, and Stereoselectivity of Rare-Earth Catalyzed Alternating Copolymerization of Polar and Nonpolar Olefins

Inorganic Chemistry, Год журнала: 2024, Номер 63(7), С. 3544 - 3559

Опубликована: Фев. 3, 2024

The direct copolymerization of polar and nonpolar olefins is great interest significance, as it the most atom-economical straightforward strategy for synthesis functional polyolefin materials. Despite considerable efforts, precise control monomer-sequence their regio- stereochemistry full challenges, related mechanistic origins are still in infancy to date. Herein, studies on model reaction Sc-catalyzed co-syndiospecific alternating anisylpropylene (AP) styrene were performed by DFT calculations. results suggest that subtle balance between electronic steric factors plays an important role during monomer insertions, a new amino-dissociated mechanism was proposed AP insertion at chain initiation. follows 2,1-si-insertion pattern, which mainly controlled caused restricted MeO···Sc interaction. As insertion, prefers 2,1-re-insertion manner its stereoselectivities influenced repulsions inserting polymer or ligand. More interestingly, found determined "steric matching" principle, quantitatively expressed buried volume metal center preinserted species. concept pocket has been successfully applied explain different performances several catalysts other reactions. insightful findings quantitative present here expected promote rational design rare-earth developing regio-, stereo-, sequence-controlled specific olefins.

Язык: 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, Год журнала: 2021, Номер 61(7)

Опубликована: Дек. 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.

Язык: Английский

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