The Carbene Chemistry of N-Sulfonyl Hydrazones: The Past, Present, and Future

Chemical Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 10, 2025

N-Sulfonyl hydrazones have been extensively used as operationally safe carbene precursors in modern organic synthesis due to their ready availability, facile functionalization, and environmental benignity. Over the past two decades, there has tremendous progress chemistry of N-sulfonyl presence transition metal catalysts, under metal-free conditions, or using photocatalysts photoirradiation conditions. Many transfer reactions are unique cannot be achieved by any alternative methods. The discovery novel development highly enantioselective new skeletal editing represent notable recent achievements hydrazones. This review describes overall made hydrazones, organized based on reaction types, spotlighting current state-of-the-art remaining challenges addressed future. Special emphasis is devoted identifying, describing, comparing scope limitations methodologies, key mechanistic scenarios, potential applications complex molecules.

Язык: Английский

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Triftosylhydrazone in Single-Atom Skeletal Editing

Accounts of Chemical Research, Год журнала: 2024, Номер unknown

Опубликована: Дек. 16, 2024

ConspectusIn the past decade, single-atom skeletal editing, which involves precise insertion, deletion, or exchange of single atoms in core skeleton a molecule, has emerged as promising synthetic strategy for rapid construction diversification complex molecules without laborious de novo processes. Among them, carbene-initiated editing is particularly appealing due to ready availability and diverse reactivities carbene species. The initial endeavors modify heteroarenes through carbon-atom insertion could date back 1881, when Ciamician Denstedt described conversion pyrroles pyridines by trapping haloform-derived free carbene. Despite its potential value, general applicability this one-carbon seen limited progress poor yields harsh reaction conditions. Significant advances via were achieved only 3 years Levin, Ball, Xu, Song, Glorius, others. hallmark these approaches facile halocyclopropanation followed regioselective ring opening facilitated expulsion halide ion. Consequently, specially designed α-halocarbene precursors, such haloform derivatives, α-halodiazoacetates, chlorodiazirines, α-chlorodiazo oxime esters, can be employed achieve Ciamician–Denstedt-type editing. This not limits types functional groups installed on expansion products but also prevents their widespread adoption, especially late-stage contexts. enduring quest develop environmentally friendly versatile superior group compatibility, application diversifications investigation mechanistic insights into carbon reactions remain fundamental objective.In our over 5 years, we have developed o-trifluoromethylbenzenesulfonylhydrazones (named Triftosylhydrazones) operationally safe easily decomposable diazo surrogates explored various challenging catalytic transfer reactions. Recently, put great efforts expanding scope unlocking triftosylhydrazones precursors Since 2018, realized range acyclic 1,3-dicarbonyls with silver carbenes access 1,4-dicarbonyls, proceeding cyclopropanation/ring-opening process. Inspired results, recently demonstrated series transition-metal-catalyzed highly selective medicinally interesting like pyrroles, indoles, 1,2-diazoles carbenic insertion. We then strained three-membered nitrogen- oxygen-containing heterocycles single-carbon atoms. In Account, present an overview achievements heterocycles, organized based three situ-generated key intermediates, cyclopropane, N-ylide, O-ylide from focus scopes, features, applications. hope that Account will provide valuable contribute development new methodologies both chemistry fields.

Язык: Английский

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Halogencarbene-free Ciamician-Dennstedt single-atom skeletal editing

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Ноя. 19, 2024

Single-atom skeletal editing is an increasingly powerful tool for scaffold hopping-based drug discovery. However, the insertion of a functionalized carbon atom into heteroarenes remains rare, especially when performed in complex chemical settings. Despite more than century research, Ciamician-Dennstedt (C-D) rearrangement limited to halocarbene precursors. Herein, we report general methodology reaction using α-halogen-free carbenes generated situ from N-triftosylhydrazones. This one-pot, two-step protocol enables various carbenes, including those previously unexplored C-D chemistry, indoles/pyrroles scaffolds access 3-functionalized quinolines/pyridines. Mechanistic studies reveal pathway involving intermediacy 1,4-dihydroquinoline intermediate, which could undergo oxidative aromatization or defluorinative form different carbon-atom products. Ciamician–Dennstedt authors

Язык: Английский

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Who is Who in the Carbene Chemistry of N‐Sulfonyl Hydrazones

Chinese Journal of Chemistry, Год журнала: 2024, Номер 42(17), С. 2071 - 2108

Опубликована: Май 27, 2024

Comprehensive Summary Over the past few decades, N ‐sulfonyl hydrazones have been recognized as alternative precursors for hazardous diazo compounds in organic synthesis, allowing diverse innovative and original chemical transformations that were otherwise difficult to achieve. This critical review summarizes major advancements carbene chemistry of hydrazones. The contents this are organized based on research conducted by leading scientists who made significant contributions field. individual transfer reactions their mechanisms, well potential applications synthesis natural products complex bioactive molecules, thoroughly discussed.

Язык: Английский

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Substituent-Controlled Regiodivergent Rearrangement of Gramine Ammonium Ylide

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

Опубликована: Янв. 30, 2025

The complicated mechanism makes the regiodivergent rearrangement of ammonium ylide seem to be out reach. Herein, we reported a gramine well controlled by substituents. Density functional theory studies reveal that with more steric hindrance substituent 2-diazo-2-arylacetate goes through stepwise yield both kinetically and thermodynamically preferred [1,2]-rearrangement product. In contrast, less ethyl diazoacetate concerted generate [2,3]-rearrangement product, which is favored as result release ring strain in transition state. This study would open up avenues grasp ylide, will promote application skeletal editing synthesis complex natural products.

Язык: Английский

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Asymmetric one-carbon ring expansion of diverse N-heterocycles via copper-catalyzed diyne cyclization

Science Advances, Год журнала: 2024, Номер 10(41)

Опубликована: Окт. 9, 2024

One-carbon ring expansion reaction of N-heterocycles has gained particular attention in the past decade because this method allows for conversion readily available into potentially useful complex ring-expanded N-heterocycles, which are inaccessible by traditional methods. However, catalytic asymmetric variant been rarely reported to date. Herein, we disclose an enantioselective one-carbon through chiral copper-catalyzed diyne cyclization, leading practical, atom-economic and divergent assembly array valuable bearing a quaternary stereocenter generally good excellent yields with enantioselectivities (up >99% ee). This protocol represents first example based on alkynes.

Язык: Английский

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Skeletal Editing Through Single Atom Insertion and Transmutation: An Insight into A New Era of Synthetic Organic Chemistry

Synthesis, Год журнала: 2024, Номер 56(24), С. 3793 - 3814

Опубликована: Авг. 20, 2024

Abstract Considering the importance of heterocycles, significantly represented in medicinal chemistry and drug development, single-atom insertion technique transmutation strategy provide productive approaches towards complicated molecular structures through heterocycle diversification. It shows a potentially powerful approach for modifying complex substrates concisely chemospecifically. Although skeletal editing applies to cyclic acyclic compounds, this review focuses on diversification carbo- heterocyclic compounds synthesizing various medicinally important molecules via technique. The classification system is based recent critical historical methods as applied aromatic rings. 1 Introduction 2 Skeletal Editing Carbon-Atom Insertion 2.1 Indoles Pyrroles Derivatives: into C=C Bond 2.2 Pyrazole Indazole an N–N 2.3 CF3 Group Heteroarenes 2.4 Imidazole C–N 2.5 Atom-to-Atom Transmutation 3 N-Atom 3.1 Nitrogen-Atom Carbocycles 3.2 Heterocycles 3.3 Carbon Nitrogen Molecular Isotopic 4 Conclusion

Язык: Английский

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Transition‐Metal‐Catalyzed Reactions Involving Trifluoro Diazo Compounds and Their Surrogates

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

Опубликована: Май 22, 2024

Abstract Fluorinated organic compounds represent an important and growing family of active ingredients in various fields, including material science, pharmaceutical chemistry biological science. Developing efficient synthetic methods toward fluorinated have attracted much attention. In recent years, transition‐metal catalyzed reaction trifluoro diazo were a powerful convenient approach to afford trifluoromethyl‐ difluoromethyl‐substituted value. this review, the progress on transition‐metal‐catalyzed reactions involving their surrogates via trifluoromethylated carbene complex is described sequence 2,2,2‐trifluorodiazoethane as precursor, ethyl 3‐trifluoro‐2‐diazo‐propionate trifluoroethylamine hydrochloride or amines CF 3 CHN 2 surrogate well aldehydes/ketones N‐sulfonylhydrazones surrogate.

Язык: Английский

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Dimethoxyacetaldehyde-N-triftosylhydrazone: Preparation and Carbene Reactivity in Cyclopropanation and Doyle–Kirmse Reactions

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Фев. 20, 2025

Herein, we developed the new, powerful, and easy-to-handle chemical reagent, dimethoxyacetaldehyde-N-triftosylhydrazone (DMHz-Tfs), as a convenient in situ source of dimethoxydiazoethane under mild conditions. We demonstrate carbene reactivity DMHz-Tfs iron-catalyzed cyclopropanation Doyle-Kirmse reactions, providing access to diverse acetal functionalized cyclopropanes homoallylic- allenyl-sulfides at gram-scale with high stereoselectivity. DFT calculations elucidated involvement most stable doublet spin state iron-carbene intermediate over other possible states.

Язык: Английский

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Reimagining Dearomatization: Arenophile-Mediated Single-Atom Insertions and π-Extensions

Accounts of Chemical Research, Год журнала: 2025, Номер unknown

Опубликована: Март 11, 2025

ConspectusDearomatization of simple aromatics serves as one the most direct strategies for converting abundant chemical feedstocks into three-dimensional value-added products. Among such transformations, cycloadditions between arenes and alkenes have historically offered effective means to construct complex polycyclic architectures. However, traditionally harsh conditions, high-energy UV light irradiation, greatly limited scope this transformation. Nevertheless, recent progress has led development visible-light-promoted dearomative photocycloadditions with expanded capable preparing bicyclic structures.A fundamentally distinct approach involves visible-light activation arenophiles, which undergo para-photocycloaddition various aromatic compounds produce arene-arenophile cycloadducts. While only transiently stable subject retro-cycloaddition, further functionalization photocycloadducts allowed a wide collection dearomatization methodologies that access products orthogonal existing biological processes. Central strategy was observation photocycloaddition reveals π-system can be functionalized through traditional olefin chemistry. Coupled subsequent [4 + 2]-cycloreversion arenophile, process acts effectively isolate single from an ring. We developed several transformations bias methodology perform single-atom insertion π-extension reactions prepare unique cannot prepared easily means.Through application epoxidation, we were able develop method epoxidation pyridines arene-oxides pyridine-oxides, respectively. Notably, when arenophile chemistry is applied arenes, transposed site native olefinic reactivity, enabling site-selectivity functionalization. As result, oxygen (aza)arenes 3-benzoxepines. When applying in context cyclopropanations, accomplish cyclopropanation yield benzocycloheptatrienes upon cycloreversion. while Buchner ring expansion powerful carbon corresponding does not ring-expanded Furthermore, could utilized synthesis novel nanographenes M-region annulative (M-APEX) reaction. Traditionally, methods rely on reactivity at K- bay-region. arenophiles activate reactivity. arenophile-mediated diarylation, followed by cycloreversion, deliver π-extended exclusive selectivity.

Язык: Английский

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