Organocatalytic radical aminoacylation of alkenes for β-aminoketone synthesis

Science China Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Окт. 14, 2024

Язык: Английский

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Recent Progress in Metal‐Free Hydroacylation Reactions of Alkenes and Alkynes

ChemistrySelect, Год журнала: 2024, Номер 9(35)

Опубликована: Сен. 12, 2024

Abstract The present review discusses the development of new metal‐free conditions for hydroacylation alkenes and alkynes under both thermal photochemical from 2018, their application to synthesis various bioactive molecules over past few years. key point highlights remarkable progress made by catalytic systems in comparison conventional metal catalysts alkenes, alkynes, arenes. Both inter‐ intramolecular reactions mechanistic pathways were discussed. most current developments several natural, pharmaceutical, heterocyclic compounds using have also been introduced.

Язык: Английский

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Cooperative NHC and Photoredox Catalyzed Radical Aminoacylation of Alkenes to Tetrahydropyridazines

Chemistry - A European Journal, Год журнала: 2024, Номер unknown

Опубликована: Июль 27, 2024

Tetrahydropyridazines constitute an important structural motif found in numerous natural products and pharmaceutical compounds. Herein, we report aminoacylation reaction of alkenes that enables the synthesis 1,4,5,6-tetrahydropyridazines through cooperative N-heterocyclic carbene (NHC) photoredox catalysis. This approach involves 6-endo-trig cyclization N-centered hydrazonyl radicals, generated via single-electron oxidation hydrazones, followed by a radical-radical coupling step. The mild process tolerates wide range common functional groups affords variety tetrahydropyridazines moderate to high yields. Preliminary investigations using chiral NHC catalysts demonstrate potential this protocol for asymmetric radical reactions.

Язык: Английский

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Stereoselective Radical Acylfluoroalkylation of Bicyclobutanes via N‐Heterocyclic Carbene Catalysis

Angewandte Chemie, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 14, 2024

Abstract Cyclobutanes are prominent structural components in natural products and drug molecules. With the advent of strain‐release‐driven synthesis, ring‐opening reactions bicyclo[1.1.0]butanes (BCBs) provide an attractive pathway to construct these three‐dimensional structures. However, stereoselective difunctionalization central C−C σ‐bonds remains challenging. Reported herein is a covalent‐based organocatalytic strategy that exploits radical NHC catalysis achieve diastereoselective acylfluoroalkylation BCBs under mild conditions. The Breslow enolate acts as single electron donor provides NHC‐bound ketyl with appropriate steric hindrance, which effectively distinguishes between two faces transient cyclobutyl radicals. This operationally simple method tolerates various fluoroalkyl reagents common functional groups, providing straightforward access polysubstituted cyclobutanes (75 examples, up >19 : 1 d.r.). combined experimental theoretical investigations this system confirm formation NHC‐derived understanding how radical‐radical coupling occurs.

Язык: Английский

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Dual N-Heterocyclic Carbene/Photoredox-Catalyzed Coupling of Acyl Fluorides and Alkyl Silanes

ACS Catalysis, Год журнала: 2024, Номер unknown, С. 17642 - 17653

Опубликована: Ноя. 15, 2024

The combination of N-heterocyclic carbene (NHC) organocatalysis with photochemical activation is becoming increasingly established as an approach for conducting radical organic reactions under mild and practical conditions. As comparatively easy to prepare handle compounds, alkyl silanes are attractive substrates chemistry desilylative mesolysis the corresponding cations known be rapid. Here, we report successful application benzyl silane derivatives source radicals in dual NHC/photoredox-catalyzed radical–radical coupling acyl fluorides. Relatively electron-rich reacted smoothly afford ketones generally good yields, while optimization NHC photocatalyst allowed a wider scope including primary substrates. Furthermore, initial experiments revealed that organosilanes bearing N-, O- S-heteroatoms can also serve sources these

Язык: Английский

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A DFT Study on the NHC-Catalyzed Reaction of Enals with Aminoacrylates: Mechanism, Regioselectivity, and Stereoselectivity

The Journal of Physical Chemistry A, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 27, 2024

DFT (M06-2X) calculations were used to study the NHC-catalyzed [3 + 3] cycloaddition of enals with aminoacrylates. The catalytic cycle begins binding NHC enal. Subsequent intramolecular proton transfer generates Breslow intermediate. This intermediate undergoes an oxidative reaction, leading formation acyl azolium intermediate, which further reacts other substrate aminoacrylate via a new C–C bond formation. step determines stereoselectivity current and re-face addition mode S-configuration is predominant. Afterward, sequential protonation, deprotonation, cyclization form six-membered cyclic upon elimination affords final product dihydropyridinone. computed enantiomeric excess (99.1% ee) in very good agreement experimentally reported value (99% ee). origin enantioselectivity traced stronger LP···π interactions between favored S-congurational transition state.

Язык: Английский

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Synthesis of Bulky 4-Amino-1,3-diarylimidazolium Salts as NHC-Ligand Precursors and Derived M/NHC Complexes (M = Cu, Pd)

Russian Journal of General Chemistry, Год журнала: 2024, Номер 94(12), С. 3263 - 3276

Опубликована: Дек. 1, 2024

Язык: Английский

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