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

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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Enantioselective Synthesis of Spirosilabicyclohexenes by Asymmetric Dual Ring Expansion of Spirosilabicyclobutane with Alkynes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(48)

Published: Oct. 7, 2022

Silaspiranes have attracted particular attention due to their chiral spiro-silicon center, which serves as an ideal carbon isostere and can endow spiro-analogs with distinct properties. Distinct from previously reported cyclization or cycloaddition strategies form 5/5-silaspiranes, we report herein the asymmetric dual ring expansion of spirosilabicyclobutanes alkynes synthesize axially spirosilabicyclohexenes bearing a novel 6/6-silaspirane framework. DFT (density functional theory) calculations provide deep insight into origin high enantioselectivity controlled by sterically demanding binaphthyl phosphoramidite ligand. Preliminary studies chiroptical properties indicate that one spirosilabicyclohexene analogs exhibit fluorescence emission, Cotton effects CPL (circularly polarized luminescence) activity.

Language: Английский

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Ring Expansion of Silacyclobutanes with Allenoates to Selectively Construct 2- or 3-(E)-Enoate-Substituted Silacyclohexenes

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(9), P. 5185 - 5196

Published: April 15, 2022

Silacycle is one of the most essential core frameworks in silicon-containing functional molecules. However, structural diversity silacycles has been largely limited due to lack general synthetic methods. Here, we report an efficient synthesis exo-cyclic enoate-substituted silacyclohexenes by ring expansion silacyclobutanes with allenoates. The reaction proceeds two regioselectivities during Si–C bond insertion. In presence Pd/PR3 catalyst, unsubstituted allenoates undergo β, γ-insertion form a Si–Cβ bond, giving 2-(E)-enoate-substituted silacyclohexenes. this pathway, chiral phosphoramidite ligand used construct stereogenic silicon center enantioselectively. second PtCl2 α-substituted γ, β-insertion Si–Cγ leading 3-(E)-enoate-substituted control experiments and density theory calculations have performed understand regio- stereochemical outcome both Pd- Pt-catalyzed reactions.

Language: Английский

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Recent advances in Pd-catalyzed asymmetric cyclization reactions

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 53(2), P. 883 - 971

Published: Dec. 18, 2023

This review aims to collect advancements in enantioselective palladium-catalyzed cyclization reactions over the past eleven years, and it is organized into thirteen sections depending on different types of transformations involved.

Language: Английский

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Recent advances in the reactions of silacyclobutanes and their applications

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(10), P. 2840 - 2855

Published: Jan. 1, 2022

This review summarizes the growing landscape in reactions of silacyclobutanes (SCBs) by highlighting fascinating progress, deconstructing mechanistic underpinnings, and drawing insight from related ring-opening expanding SCBs.

Language: Английский

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Nickel-Catalyzed Reductive [4 + 1] Sila-Cycloaddition of 1,3-Dienes with Dichlorosilanes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(24), P. 13008 - 13014

Published: June 7, 2023

Transition-metal-catalyzed sila-cycloaddition has been a promising tool for accessing silacarbocycle derivatives, but the approach limited to selection of well-defined sila-synthons. Herein, we demonstrate potential chlorosilanes, which are industrial feedstock chemicals, this type reaction under reductive nickel catalysis. This work extends scope coupling from carbocycle synthesis and single C-Si bond formation reactions. The proceeds mild conditions shows good substrate functionality tolerance, it offers new access silacyclopent-3-enes spiro silacarbocycles. optical properties several dithienosiloles as well structural variations products demonstrated.

Language: Английский

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Triftosylhydrazone in Single-Atom Skeletal Editing

Accounts of Chemical Research, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 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.

Language: Английский

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Selective Access to Silacyclopentanes and Homoallylsilanes by La-Catalyzed Hydrosilylations of 1-Aryl Methylenecyclopropanes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(6), P. 4060 - 4067

Published: Feb. 1, 2024

Methylenecyclopropanes (MCPs) have emerged as versatile building blocks in synthetic chemistry because of their unique reactivity. However, metal-catalyzed hydrosilylation MCPs has met with very limited successes. In this paper, catalytic selective hydrosilylations some primary silanes using an ene-diamido lanthanum ate complex the catalyst were described. The reactions resulted formation silacyclopentanes and (E)-homoallylsilanes, respectively, depending on substituents MCPs. via a cascade inter- intramolecular mechanism is strongly supported by control deuteration-labeling experiments DFT calculations. reactivity selectivity could be attributed to large ion structure catalyst.

Language: Английский

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Catalytic Asymmetric Construction of C‐ and Si‐Stereogenic Silacyclopentanes via Hydrosilylation of Arylmethylenecyclopropanes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(48)

Published: Aug. 14, 2024

Silacycles have exhibited significant potential for application in the fields of medicinal chemistry, agrochemistry, and materials science. Accordingly, development effective methods synthesizing these compounds has attracted increasing attention. Here, we report an efficient Cu-catalyzed enantioselective hydrosilylation arylmethylenecyclopropanes with hydrosilanes, that allows rapid assembly various enantioenriched carbon- silicon-stereogenic silacyclopentanes good yields excellent enantioselectivities diastereoselectivities under mild conditions. Further stereospecific transformation Si-H bond on chiral silicon center expands diversity C- Si-stereogenic silacyclopentanes.

Language: Английский

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Ring Expansion toward Disila‐carbocycles via Highly Selective C−Si/C−Si Bond Cross‐Exchange

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(16)

Published: Feb. 23, 2024

Herein, we successfully inhibited the preferential homodimerization and C-Si/Si-H bond cross-exchange of benzosilacyclobutenes monohydro-silacyclobutanes achieved first highly selective C-Si/C-Si reaction by deliberately tuning Ni-catalytic system, which constitutes a powerful atom-economical ring expansion method for preparing medium-sized cyclic compounds bearing two silicon atoms at junction, are otherwise inaccessible. The DFT calculation explicitly elucidated pivotal role Si-H silacyclobutanes high strain substrates in realizing C-Si bonds cleavage reformation catalytic cycle.

Language: Английский

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