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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Palladium/TY-Phos-Catalyzed Asymmetric Heck/Tsuji–Trost Reaction of o-Bromophenols with 1,3-Dienes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(8), P. 4378 - 4383

Published: Feb. 16, 2023

2,3-Dihydrobenzofurans are crucial building blocks in the synthesis of natural products and pharmaceutical molecules. However, their asymmetric has been a long-standing formidable challenge so far. In this work, we developed highly enantioselective Pd/TY-Phos-catalyzed Heck/Tsuji-Trost reaction o-bromophenols with various 1,3-dienes, allowing expedient access to chiral substituted 2,3-dihydrobenzofurans. This features excellent regio- enantiocontrol, high functional group tolerance, easy scalability. More importantly, demonstration method as valuable tool for construction optically pure (R)-tremetone fomannoxin is highlighted.

Language: Английский

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Sadphos as Adaptive Ligands in Asymmetric Palladium Catalysis

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

Published: Jan. 31, 2024

ConspectusPalladium catalysis, as one of the most important strategies in asymmetric synthesis, has continuously attracted attention organic chemists. With development chiral ligands, increasingly challenging reactions and substantial progress catalysis are being realized.Since 2014, we have focused on exploiting a series sulfinamide phosphine ligands called "Sadphos," including Ming-Phos, Xu-Phos, Xiao-Phos, Xiang-Phos, TY-Phos, PC-Phos, GF-Phos, WJ-Phos. These can be easily prepared two to four steps using commercial materials. new types shown remarkable performance transition-metal-catalyzed reactions, especially Pd-catalyzed transformations. X-ray diffraction analysis, mechanistic studies, density functional theory calculations revealed that Sadphos coordinate with Pd0 PdII species Pd0/P, Pd0/P,S, or PdII/P,O modes.This Account summarizes our recent efforts toward palladium-catalyzed enantioselective ligands. were found privileged very crucial promote by increasing reactivity enantioselectivity. Ming-Phos is an effective ligand coupling intramolecular Heck providing highly trisubstituted allenes, axially anilides, gem-diarylmethine silanes, disubstituted dihydroisoquinolinones. Incorporation electron-rich cyclohexyl group moiety afforded which showed unique effect transformations, reductive Heck, dearomative Mizoroki–Heck, tandem Heck/Suzuki coupling, carboiodination, carboamination, cross-coupling reactions. Using similar strategy, synthesized more electron–rich TY-Phos Xiang-Phos bearing t-butyl 1-adamantyl at P atoms, respectively. Regarding stereoelectronic features, these characteristic best choice satisfy requirements fluoroarylation gem-difluoroalkenes, intermolecular α-arylation aldehydes, carboetherification alkenyl oximes, carboheterofunctionalization 2,3-dihydrofurans. Compared aforementioned attractive features high nucleophilicity originating from CH2PPh2 ortho-substituent side aryl ring, presumably responsible for its efficiency. The Pd/Xiao-Phos catalyst system shows good secondary oxides, affording P-stereogenic products multiple molecular skeletons. modification basic backbone introducing xanthene skeleton motivated us design synthesize monophosphines, named PC-Phos GF-Phos. various arylation sulfenate anions, denitrogenative cyclization benzotriazoles, dearomatization indoles. practicability GF-Phos was validated three-component N-tosylhydrazones, halides, terminal alkynes, well N-tosylhydrazones vinyl iodides pendent amines. In addition, ferrocene-derived WJ-Phos employed Suzuki–Miyaura reaction, biaryl monophosphine oxides excellent enantiomeric excesses.

Language: Английский

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Enantioselective Synthesis of Dihydropyrazoles by Palladium/Xu‐Phos‐Catalyzed Alleneamination of β,γ‐Unsaturated Hydrazones with Propargylic Acetates

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(20)

Published: March 10, 2023

The palladium-catalyzed asymmetric carboamination reaction is one of the most significant transformations in organic chemistry. Herein, we report first alleneamination β,γ-unsaturated hydrazones with propargylic acetates. This protocol enables efficient installation various multisubstituted allene groups onto dihydropyrazoles good yields excellent enantioselectivities. chiral sulfinamide phosphine ligand Xu-5 exhibits highly stereoselective control this protocol. salient features include readily available starting materials, a broad substrate scope, an easy scale-up, mild conditions and versatile transformations.

Language: Английский

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Palladium-catalyzed asymmetric carbene coupling en route to inherently chiral heptagon-containing polyarenes

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 18, 2024

Developing facile and direct synthesis routes for enantioselective construction of cyclic π-conjugated molecules is crucial. However, originate chirality from the distorted structure around heptagon-containing polyarenes largely overlooked, all-carbon remains a challenge. Herein, we present highly route fabricating all carbon via palladium-catalyzed carbene-based cross-coupling benzyl bromides N-arylsulfonylhydrazones. A wide range nonplanar, saddle-shaped tribenzocycloheptene derivatives are efficiently prepared in high yields with excellent enantioselectivities using this approach. In addition, stereochemical stability experiments show that these have inversion barriers.

Language: Английский

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Chiral oxalamide phosphine (COAP)-Pd-catalyzed enantioselective cascade formal [4 + 1] annulation for enantioenriched 2,3-disubstituted indolines and further DFT study on regio- and stereocontrol

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(9), P. 2138 - 2146

Published: Jan. 1, 2023

COAP-Pd-catalyzed asymmetric cascade formal [4 + 1] annulation was developed between racemic vinyl benzoxazinones and N -tosylhydrazone sodium salts, affording trans -2,3-disubstituted indolines in good yields with high stereoselectivity.

Language: Английский

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Enantioselective and Regiodivergent Synthesis of Propargyl‐ and Allenylsilanes through Catalytic Propargylic C−H Deprotonation

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

Published: Feb. 13, 2024

Abstract We report a highly enantioselective intermolecular C−H bond silylation catalyzed by phosphoramidite‐ligated iridium catalyst. Under reagent‐controlled protocols, propargylsilanes resulting from C(sp 3 )−H functionalization, as well the regioisomeric and synthetically versatile allenylsilanes, could be obtained with excellent levels of enantioselectivity good to control propargyl/allenyl selectivity. In case unsymmetrical dialkyl acetylenes, selectivity for functionalization at less‐hindered site was also observed. A variety electrophilic silyl sources (R SiOTf R SiNTf 2 ), either commercial or in situ ‐ generated, were used reagents, broad range simple functionalized alkynes, including aryl alkyl 1,3‐enynes, drug derivatives successfully employed substrates. Detailed mechanistic experiments DFT calculations suggest that an η ‐propargyl/allenyl Ir intermediate is generated upon π‐complexation‐assisted deprotonation undergoes outer‐sphere attack silylating reagent give propargylic silanes, latter step identified enantiodetermining step.

Language: Английский

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Pd-Catalyzed Asymmetric Aza-Heck Cyclization/Sonogashira Reaction of Alkene-Tethered Oxime Esters and Alkynes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(7), P. 5305 - 5313

Published: March 26, 2024

Over the past few decades, Narasaka–Heck-type difunctionalization of tethered alkenes has emerged as a powerful strategy to produce heterocyclic scaffolds. However, asymmetric synthesis rarely been explored. Herein, we report robust palladium-catalyzed enantioselective Narasaka–Heck cyclization–Sonogashira reaction alkene-tethered oxime esters and terminal alkynes. By employing new Ming-Phos ligand, obtain high yields pyrrolines with quaternary stereocenter enantioselectivities under mild conditions. Density functional theory (DFT) study reveals weak interaction between aromatic ring substrate fragment naphthyl group in which probably accounts for stereoselectivity.

Language: Английский

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Theoretical study of an N-heterocyclic carbene-catalyzed annulation reaction between an enal and a β-silyl enone: Mechanism and origin of stereoselectivity

Molecular Catalysis, Journal Year: 2023, Volume and Issue: 551, P. 113621 - 113621

Published: Oct. 27, 2023

Language: Английский

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

Chinese Journal of Chemistry, Journal Year: 2024, Volume and Issue: 42(17), P. 2071 - 2108

Published: May 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.

Language: Английский

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