1H-1,2,3-Triazol-5-ylidenes as Catalytic Organic Single-Electron Reductants

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(5), P. 2933 - 2938

Published: Jan. 22, 2024

Most of the known single-electron reductants are either metal based reagents, used in a stoichiometric amount, or combination an organic species and photocatalyst. Here we report that 1

Language: Английский

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New class of RSO₂-NHC ligands and Pd/RSO₂-NHC complexes with tailored electronic properties and high performance in catalytic C–C and C–N bonds formation

Dalton Transactions, Journal Year: 2023, Volume and Issue: 52(34), P. 12067 - 12086

Published: Jan. 1, 2023

Imidazolium salts have found ubiquitous applications as N-heterocyclic carbene precursors and metal nanoparticle stabilizers in catalysis metallodrug research. Substituents directly attached to the imidazole ring can a significant influence on electronic, steric, other properties of NHC-proligands well their complexes. In present study, for first time, new type Pd/NHC complex with RSO2 group imidazol-2-ylidene ligand core was designed synthesized. The electronic structural features ligands were evaluated by means experimental computational methods. Interestingly, introduction 4-aryl(alkyl)sulfonyl only slightly decreased electron donation, but it significantly increased π-acceptance enhanced buried volume (%Vbur) imidazol-2-ylidenes. New complexes obtained through selective C(2)H-palladation some synthesized 4-RSO2-functionalized imidazolium under mild conditions. Several demonstrated good activity model cross-coupling reactions, outperforming similar non-substituted NHC ligands.

Language: Английский

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Boosting N-Heterocyclic Carbene Radical Organocatalysis with Nickel Chemistry: A Rational Mechanistic Study-Based Approach

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(9), P. 7149 - 7156

Published: April 23, 2024

A cooperative NHC/nickel catalytic methodology has been developed for the synthesis of ketones employing aromatic aldehydes and tertiary alkyl iodides. All key steps postulated cycle were validated with comprehensive stoichiometric electrochemical studies, including reduction NiII by deprotonated Breslow intermediate, Ni0 promoted halogen-atom abstraction to generate transient radicals, coupling between latter persistent acyl thiazolium radical intermediate. Such a broadly proposed accepted, yet elusive, intermediate isolated studied single-crystal X-ray diffraction study.

Language: Английский

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Improved Protocols for the Synthesis of Precursors of Thiazol-2-ylidene N-Heterocyclic Carbenes

Synlett, Journal Year: 2024, Volume and Issue: 35(18), P. 2097 - 2100

Published: March 10, 2024

Abstract We report improved protocols for the synthesis of thiazolium precatalysts from primary amines, carbon disulfide, and α-halo ketones. For N-alkyl-substituted derivatives, yields corresponding thiazolethiones can be dramatically by isolating intermediate dithiocarbamates. In most cases, meta-chloroperbenzoic acid advantageously replace H2O2 in acetic oxidation into thiazoliums. This approach was applied to a featuring 2-adamantyl N-substituent, persistent carbene, its dimer.

Language: Английский

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N-Heterocyclic Carbene Catalysis for Polycyclic Benzazepines Assembly: Regioselective Intramolecular Tandem Radical Cyclization

Organic Letters, Journal Year: 2024, Volume and Issue: 26(42), P. 9068 - 9072

Published: Oct. 11, 2024

A variety of polycyclic benzazepines were rapidly constructed by NHC-catalyzed regioselective redox-neutral intramolecular tandem cyclization. Initial mechanistic studies revealed that a SET radical process was possibly involved.

Language: Английский

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Boosting N-Heterocyclic Carbene Radical Organocatalysis with Nickel Chemistry: A Rational Mechanistic Study-based Approach.

Published: Feb. 21, 2024

A cooperative NHC/nickel catalytic methodology has been developed for the synthesis of ketones employing aromatic aldehydes and tertiary alkyl iodides. All key steps postulated cycle were validated with comprehensive stoichiometric electrochemical studies, including reduction NiII by deprotonated Breslow intermediate, Ni0 promoted halogen-atom abstraction to generate transient radicals coupling between latter persistent acyl thiazolium radical intermediate. Such broadly proposed accepted, yet elusive, intermediate isolated stud-ied a single-crystal X-ray diffraction study.

Language: Английский

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5‐N,N‐Diarylaminothiazoles with Electron‐Accepting Groups: Synthesis, Photophysical Properties, and Their Application for the Detection of Hydrazine Hydrate

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 27(3)

Published: Nov. 8, 2023

Abstract 5‐N,N‐diarylaminothiazoles containing cyano and nitro groups were synthesized using the Pd‐catalyzed Buchwald‐Hartwig amination reaction with good yields. The group in resultant thiazole was reduced to a formyl group. This then subjected Knoevenagel condensation reaction, leading formation of thiazoles dicyanovinyl an amino group, which subsequently reacted triphosgene, yielding isocyanate These thiazoles, their electron‐accepting properties, demonstrated absorption emission spectra at longer wavelengths. Notably, displayed red emission. Tests for detection hydrazine, hazardous volatile organic compound, conducted thiazoles. results showed that effectively responded hydrazine hydrate, evidenced by changes spectra. change color also visibly detectable naked eye.

Language: Английский

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Singly and doubly oxidized carbenes and their applications in catalysis

Chem Catalysis, Journal Year: 2024, Volume and Issue: unknown, P. 101159 - 101159

Published: Nov. 1, 2024

Language: Английский

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