Tertiary‐Amine Controlled (3+3) or (4+2) Annulations of β′‐Acetoxy Allenoates with N‐Sulfonyl Ketimines: An Entry to m‐Teraryl and Fused Dihydropyridines

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(5), С. 1165 - 1175

Опубликована: Янв. 10, 2024

Abstract Lewis base dependent (3+3) and (4+2) annulations of β′ ‐acetoxy allenoates with N ‐sulfonyl ketimines offer m ‐teraryl fused dihydropyridines varying substituents depending on the tertiary amine as well subtle changes in reaction conditions. The triazabicyclodecene (TBD)‐catalyzed annulation involves 1,2‐elimination followed by 6‐ endo ‐dig cyclization key steps delivering 1,4‐hydropyridines. same reactants under DMAP catalysis via Mannich coupling, rather than C−N bond cleavage/aromatization. Key intermediates have been identified HRMS studies.

Язык: Английский

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Recent Natural Product Total Syntheses Involving Cycloadditions of Allenes

Chinese Journal of Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Фев. 11, 2025

Comprehensive Summary Allenes, characterized by their cumulated carbon–carbon double bonds, have emerged as indispensable synthons in the construction of complex natural products. Their unique reactivity and stereochemical properties render allenes a powerful tool for efficient streamlined total synthesis structurally intricate This review comprehensively summarizes syntheses products involving allene cycloaddition reactions reported over past decade (2014—2024). Among nearly 20 reviewed, [2+1], [2+2], [3+2], [4+2], [4+3], [5+1] [2+2+1] are most important transformations to construct key skeleton. is because ability form multiple bonds single step with high atom economy, stereoselectivity, regioselectivity, often under mild conditions. The strategic application these forming controlling stereochemistry makes them practical assembly molecular frameworks. With ongoing exploration methods generation, particularly enantioselective approaches, continued discovery novel cyclization allenes, chemistry will maintain its crucial role Key Scientists

Язык: Английский

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Synthesis of benzooxepane-fused cyclobutene derivatives via Pd-catalyzed cascade reactions of haloarenes and diynylic ethers

Chemical Communications, Год журнала: 2024, Номер 60(44), С. 5707 - 5710

Опубликована: Янв. 1, 2024

A tandem palladium-catalyzed Sonogashira coupling, propargyl–allenyl isomerization, and [2+2] cycloaddition sequence between electron-deficient haloarenes 1,8-diynylic ethers is developed.

Язык: Английский

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Catalytic Schmittel-Type [2+2] Cycloaddition of γ-Alkynyl Diazoacetates with Terminal Alkynes for Accessing Cyclobuta[a]indenes

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 17, 2025

Instead of the conventional [4+2] cycloaddition, a regioselective Schmittel-type [2+2] cycloaddition yne–allene esters, generated in situ from copper-catalyzed dediazotized coupling γ-alkynyl diazoacetates with terminal alkynes, is reported, enabling bicyclization process to produce diverse array C1-arylated cyclobuta[a]indenes moderate good yields. The protocol features wide functional group compatibility, mild reaction conditions, and experimental simplicity, holding significant potential for building new tricyclic cyclobutenes.

Язык: Английский

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Multicomponent Annulative SO₂ Insertion of Heteroatom‐Linked 1,7‐Diynes for Accessing Tricyclic Sulfones

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(10), С. 1693 - 1698

Опубликована: Май 6, 2023

Abstract A metal‐free radical multicomponent bicyclization of heteroatom‐linked 1,7‐diynes with aryl diazonium tetrafluoroborates and DABCO‐bis(sulfurdioxide) (DABSO) is reported, enabling annulative SO 2 insertion access to produce two types skeletally diverse tricyclic sulfones, namely, thieno[3,4‐ c ]quinoline 2,2‐dioxides ]chromene 2,2‐dioxides, moderate good yields by simply tuning the linkers 1,7‐diynes. This protocol demonstrates remarkable compatibility regarding N ‐ O ‐linked different substitution patterns tetrafluoroborates. magnified image

Язык: Английский

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PhI(OAc)₂-mediated aminoacyloxylation of β,γ-unsaturated hydrazones using Togni reagent II as an acyloxyl precursor

Organic & Biomolecular Chemistry, Год журнала: 2023, Номер 21(33), С. 6757 - 6761

Опубликована: Янв. 1, 2023

A metal-free protocol for the direct construction of C(sp2)-N and C-O bonds via a PhI(OAc)2-mediated dehydrogenative aminoacyloxylation β,γ-unsaturated hydrazones with Togni reagent II is reported. Initiated by carboxyl-containing species generated in situ from II, this method offers new solution regioselective functionalization at remote site on hydrazones, thus providing straightforward synthesis acyloxyl-substituted pyridazines. This reaction features broad substrate scope mild conditions.

Язык: Английский

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Pd-Catalyzed Enantioselective Creation of All-Carbon Quaternary Center with 2,3-Allenylic Carbonates

Organic Letters, Год журнала: 2024, Номер 26(12), С. 2349 - 2353

Опубликована: Март 15, 2024

Enantioselective construction of all-carbon quaternary centers has been achieved via the palladium-catalyzed highly enantioselective allenylation oxindoles with 2,3-allenylic carbonates to afford a variety optically active allene products, which contain oxindole units different functional groups, in high ee. The corresponding synthetic applications have also demonstrated.

Язык: Английский

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Palladium‐Catalyzed Long‐Range Isomerization of Aryl Olefins

Chinese Journal of Chemistry, Год журнала: 2022, Номер 40(19), С. 2269 - 2275

Опубликована: Июнь 14, 2022

Comprehensive Summary Long‐range olefin isomerization could lead to the remote functionalization of hydrocarbon chains, which is advantageous with regards atom‐, step‐, and redox economy. However, present methodologies for long‐range are mainly focused on heteroatom directed migration; studies using aryl groups as directing group limited. The limited examples either utilize olefins special substituted a benzene ring, or use elaborately optimized ligands co‐catalysts accelerate isomerization. A more simple catalytic system general olefins, without need co‐catalysts, was be developed. Herein, we report Pd‐catalyzed (up 15 units) via 1,2‐hydrogen shift mechanism. This methodology provides pathway participation co‐catalysts.

Язык: Английский

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Pd(II)/N,N′-Disulfonyl bisimidazoline-catalyzed asymmetric arylation of isoquinoline-1,3,4-trione-derived ketimines

Green Synthesis and Catalysis, Год журнала: 2024, Номер 5(3), С. 165 - 169

Опубликована: Авг. 1, 2024

A palladium/chiral N,N′-disulfonyl bisimidazoline (Bim)-catalyzed asymmetric addition of arylboronic acids to isoquinoline-1,3,4-trione-derived ketimines is reported, leading the generation a series functionalized isoquinoline-1,3(2H,4H)-diones bearing one quaternary carbon-amino functionality in good excellent yields with ≥95% ee most cases. The reaction has remarkable compatibility both substrate scopes, providing highly enantioselective entry chiral heterocyclic α-tertiary amines.

Язык: Английский

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Olefin skeletal rearrangement enabling access to multiarylated N-sulfonyl amidines

Chemical Communications, Год журнала: 2024, Номер 60(11), С. 1492 - 1495

Опубликована: Янв. 1, 2024

A novel base-promoted olefin skeletal rearrangement strategy from para -quinone methides ( p -QMs) and N -fluoroarenesulfonamides is reported, enabling direct nitrogen insertion of olefins to produce multiarylated Z )- -sulfonyl amidines.

Язык: Английский

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