2H‐Azirines: Recent Progress in Synthesis and Applications

European Journal of Organic Chemistry, Год журнала: 2024, Номер 27(11)

Опубликована: Янв. 29, 2024

Abstract 2H ‐arizines are important three‐membered heterocycles in organic chemistry. Recently, many advances the synthesis and functionalization of have been reported. Neber rearrangement, isomerization isoxazole, oxidation enamine, C−H bond activation, decomposition vinyl azide, alkyne, multi‐step developed for efficient assembly ‐azirines. As versatile highly strained unsaturated heterocycles, ‐azirines can be used as distinctive building blocks towards significant functional groups, attracted extensive attention fabrication numerous heterocycles. Recent studies focused on [3+n] ring‐expansion reactions, nucleophilic addition C=N double or continuous followed by cyclization, ring‐opening to acyclic compounds, substitution sp 3 ‐C−H One most critical challenges is seeking a selective opening specific three bonds azirine circle, some what achieved basis metal catalyst, photocatalysis, combination catalyst photocatalysis. In this review, recent involving reactivity accompanied with breakthroughs summarized. The review mainly covers period from 2019 2023.

Язык: Английский

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The literature of heterocyclic chemistry, part XXII, 2022

Advances in heterocyclic chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Язык: Английский

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Synthesis of Azirinyl Ethynyl Ketones and Their Use in the Preparation C(O)C≡CR-Substituted NH-Pyrroles/NH-Imidazoles and Azole–Azine/Azole–Azole Heterocyclic Hybrids

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Фев. 24, 2025

Azirinyl-substituted conjugated ynones were first synthesized by the reaction of lithiated acetylenes with 2H-azirine-2-carbonyl chlorides. Azirinyl ethynyl ketones containing only a C(O)C≡CR substituent at position 2 azirine ring are good precursors for obtaining α-C(O)C≡CR substituted NH-pyrroles and 5-[C(O)C≡CR]-substituted NH-imidazoles, reacting selectively moiety 1,3-diketones arylamidines, respectively. Various N-heterocyclic hybrids (pyrrole-pyrimidine, imidazole-pyrimidine, pyrrole-isoxazole, imidazole-isoxazole, pyrimidine-pyrrole-thiophene, pyrrole-pyrimidine-thiophene, imidazole-pyrimidine-thiophene, isoxazole-pyrrole-thiophene) have been prepared based on orthogonal or domino reactions an moieties azirinyl ketones.

Язык: Английский

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Cyclic Bifunctional Reagents Enabling a Strain-Release-Driven Formal [3 + 2] Cycloaddition of 2H-Azirines by Cascade Energy Transfer

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 10, 2025

The energy transfer (EnT)-catalyzed ring opening and further decarboxylation of isoxazole-5(4H)-ones enables the in situ generation strained 2H-azirines. Subsequent selective C(sp2)-C(sp3) bond cleavage azirine intermediate allows a formal [3 + 2] cycloaddition with wide range electrophiles, unlocking access to valuable pyrroline-type moieties. Mechanistic experiments combination density functional theory (DFT) calculations revealed unique nature EnT-cascade process for three-membered aza-cycle while providing insight into regio- diastereoselectivity annulation. This mild straightforward method ensures rapid construction highly substituted cyclic imines, which can be easily converted pyrrolidines, fused oxaziridines, biologically relevant β-amino acid precursors.

Язык: Английский

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Three-Membered Aluminacycles

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(24), С. 12967 - 12986

Опубликована: Июнь 8, 2023

Three-membered-ring scaffolds of carbocycles, namely, cyclopropanes and cyclopropenes, are ubiquitous in natural products pharmaceutical molecules. These molecules exhibit a peculiar reactivity, their applications as synthetic intermediates versatile building blocks organic synthesis have been extensively studied over the past century. The incorporation heteroatoms into three-membered cyclic structures has attracted significant attention, reflecting fundamental differences electronic/geometric reactivities compared to carbon congeners associated potential for exploitation applications. Recently, chemistry low-valent aluminum species, alumylenes, dialumenes, aluminyl anions, dramatically developed, which allowed access hitherto unprecedented aluminacycles. This Perspective focuses upon advances aluminacycles, including protocols, spectroscopic structural properties, reactivity toward various substrates small

Язык: Английский

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Light-induced synthesis of 2H-azirines and its applications in organic chemistry

Journal of Saudi Chemical Society, Год журнала: 2024, Номер 28(2), С. 101831 - 101831

Опубликована: Март 1, 2024

2H-azirines have represented versatile building motifs in the domain of organic chemistry owing to their excellent reaction activity induced by high strain three-membered ring species. Over past decades, brilliant achievements been made 2H-azirine involving construction as well transformation such functional compounds. In presence transition metals, strong bases or oxidants, could be converted into corresponding products under harsh conditions. Different from traditional catalytic methods, utilization photochemistry has proved an extremely fascinating protocol that facilitates blocks diverse substrates and further conversion various derivatives with interesting biological activities. this regard, more light-driven synthetic approaches featuring efficiency mild conditions developed. Herein, we summarized accessibility applications powerful precursors key intermediates for synthesis biologically promising molecules photocatalytic

Язык: Английский

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Azirine Weinreb amides: preparation and use in the synthesis of 2-acylated aziridines and azirines

Tetrahedron, Год журнала: 2024, Номер 167, С. 134255 - 134255

Опубликована: Сен. 6, 2024

Язык: Английский

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Organocatalysts for the Asymmetric Neber reaction: Synthesis of Chiral 2‐(Tetrazol‐5‐yl)‐2H‐Azirines

ChemistrySelect, Год журнала: 2023, Номер 8(35)

Опубликована: Сен. 19, 2023

Abstract ‐ Several novel organocatalysts derived from β‐ and γ‐lactam‐fused thiazolidines L ‐phenylalanine‐based were efficiently synthetized. These organocatalysts, as well other previously developed thiazolidine‐derived thioureas, tested in the asymmetric one‐pot Neber reaction of β‐ketoxime‐1 H ‐tetrazoles towards chiral 2‐(tetrazol‐5‐yl)‐ 2H ‐azirines. The results obtained when using thioureas only differing lactam ring size demonstrate that presence 6β‐lactam catalysts is a requirement to achieve high enantioselectivity studied transformation. new 6β‐aminopenicillanic acid‐derived thiourea afforded R enantiomer 3‐phenyl‐2‐(tetrazol‐5‐yl)‐2 ‐azirine with >99 % ee .

Язык: Английский

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Trading Symmetry for Stereoinduction in Tetradentate, non‐C₂‐Symmetric Fe(II)‐Complexes for Asymmetric Catalysis

Chemistry - A European Journal, Год журнала: 2023, Номер 29(32)

Опубликована: Апрель 27, 2023

A series of stereogenic-at-metal iron complexes comprising a non-C2 -symmetric chiral topology is introduced and applied to asymmetric 3d-transition metal catalysis. The iron(II) are built from tetradentate N4-ligands containing proline-derived amino pyrrolidinyl backbone which controls the relative (cis-α coordination) absolute metal-centered configuration (Λ vs. Δ). Two chloride ligands complement octahedral coordination sphere. modular composition facilitates straightforward incorporation different terminal coordinating heteroaromatic groups into scaffold. influence various combinations was evaluated in an ring contraction isoxazoles 2H-azirines revealing that decrease symmetry beneficial for stereoinduction obtain products up 99 % yield with 92 ee. Conveniently, catalysis feasible under open flask conditions bench-stable dichloro exhibiting high robustness towards oxidative or hydrolytic decomposition. versatility non-racemic subsequently showcased conversion variety quaternary α-amino acid derivatives.

Язык: Английский

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Design of Stereogenic‐at‐Iron Catalysts with a (3+2+1)‐Ligand Sphere

European Journal of Inorganic Chemistry, Год журнала: 2023, Номер 26(23)

Опубликована: Июнь 7, 2023

Abstract A stereogenic‐at‐iron(II) catalyst scaffold is introduced which contains one coordinated meridional tridentate imidazolidin‐2‐ylidene‐functionalized 2,2′‐bipyridine, bidentate pyrazolylpyridine, and monodentate acetonitrile ligand. This (3+2+1)‐coordination sphere implements a stereogenic iron center. carbon stereocenter in the N‐heterocyclic carbene moiety controls absolute metal‐centered configuration. The bench‐stable diamagnetic iron(II) complexes can be synthesized highly diastereoselective fashion from dibromide an efficient one‐pot coordination reaction. obtained enantiopure were applied as chiral catalysts ring contraction of isoxazole to 2 H ‐azirine (quantitative yields, up 90 : 10 er).

Язык: Английский

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