Copper‐Catalyzed Oxidative [1+2+1+2] Cascade Cyclization of N,N‐Dimethyl Enaminones with Benzylamines: A Facile Access to Functionalized 1,4‐Dihydropyridines

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(28)

Published: Feb. 24, 2023

Using benzylamines as the C4 source of 1,4-dihydropyridines (1,4-DHPs), a Cu-catalyzed oxidative [1+2+1+2] cascade cyclization for synthesis 1,4-DHPs was firstly developed. A broad range easily available N,N-dimethyl enaminones and are employed smoothly to provide diverse with high efficiency. This method is performed by one-pot C(sp3 )-H bond functionalization/C(sp3 )-N cleavage/cyclization strategy form simultaneously two )-C(sp2 ) bonds, C(sp2 1,4-DHP ring.

Language: Английский

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Copper-Catalyzed Enaminone C(sp²)–N Bond Phosphonation for Stereoselective Synthesis of Alkenylphosphonates

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(14), P. 9861 - 9868

Published: June 30, 2021

A direct enaminone C–N bond coupling functionalization that generates a new C–P using dialkyl phosphonate for the efficient and stereoselective synthesis of (E)-alkenylphosphonates is reported. The reactions toward target products proceed well with broad scope, disclosing valuable synthetic application enaminones by interesting C(sp2)–N elaboration.

Language: Английский

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Chemoselectivity of the CuAAC/Ring Cleavage/Cyclization Reaction between Enaminones and α-Acylketenimine

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(4), P. 2190 - 2199

Published: Jan. 27, 2024

Ketenimines represent an important class of reactive species, useful synthetic intermediates, and synthons. However, in general, ketenimines preferentially undergoes nucleophilic addition reactions with hydroxyl amino groups, carbon functional groups remain a less studied subset such systems. Herein, we develop straightforward syntheses pyridin-4(1H)-imines that is achieved by cyclization reacting enaminone unit α-acylketenimine which generated from the sulfonyl azides terminal ynones situ (CuAAC/Ring cleavage reaction). The cascade process starts α-C instead group, attacking electron-deficient central ketenimine, chemoselectivity unconventional products were formed intramolecular cyclization.

Language: Английский

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Highly Regioselective and Chemoselective [3 + 3] Annulation of Enaminones with ortho-Fluoronitrobenzenenes: Divergent Synthesis of Aposafranones and Their N-Oxides

Organic Letters, Journal Year: 2021, Volume and Issue: 23(8), P. 3032 - 3037

Published: April 1, 2021

A base-promoted unprecedented strategy for the regioselective and chemoselective divergent synthesis of highly functionalized aposafranones their N-oxides has been developed from [3 + 3] annulation enaminones with o-fluoronitrobenzenenes. This novel synthetic offers an alternative method construction are meaningful in fields both biology organic synthesis. The established protocol explores scope enaminones, it expands application nitro-based cyclization.

Language: Английский

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Selective Reductive Dimerization of CO₂ into Glycolaldehyde

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(8), P. 4568 - 4575

Published: March 31, 2021

The selective dimerization of CO2 into glycolaldehyde is achieved in a one-pot two-step process via formaldehyde as key intermediate. first step concerns the iron-catalyzed reduction formation and controlled hydrolysis bis(boryl)acetal compound. second carbene-catalyzed C–C bond to afford glycolaldehyde. Both carbon atoms arise from proven by labeling experiment with 13CO2. This hybrid organometallic/organic catalytic system employs mild conditions (1 atm CO2, 25 80 °C less than 3 h) low loadings 2.5%, respectively). Glycolaldehyde obtained 53% overall yield. appealing reactivity exemplified (i) leading C4 aldose compounds (ii) tri-component Petasis–Borono–Mannich reaction generating C–N bonds one process.

Language: Английский

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Enantioselective Reductive Oligomerization of Carbon Dioxide into l-Erythrulose via a Chemoenzymatic Catalysis

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(39), P. 16274 - 16283

Published: Sept. 21, 2021

A cell-free enantioselective transformation of the carbon atom CO2 has never been reported. In urgent context transforming into products high value, enantiocontrolled synthesis chiral compounds from would be highly desirable. Using an original hybrid chemoenzymatic catalytic process, we report herein reductive oligomerization C3 (dihydroxyacetone, DHA) and C4 (l-erythrulose) carbohydrates, with perfect enantioselectivity latter product. This was achieved key intermediacy formaldehyde. is first reduced selectively by 4e– iron-catalyzed hydroboration reaction, leading to isolation complete characterization a new bis(boryl)acetal compound derived dimesitylborane. aqueous buffer solution at 30 °C, this readily releases formaldehyde, which then involved in selective enzymatic transformations, giving rise either (i) DHA using formolase (FLS) catalysis or (ii) l-erythrulose cascade reaction combining FLS d-fructose-6-phosphate aldolase (FSA) A129S variant. Finally, nature synthesized noteworthy, since carbohydrates are interest for chemical pharmaceutical industries. The present results prove that de novo as sustainable source possible alternative pathway addition intensely studied biomass extraction syntheses fossil resources.

Language: Английский

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Transient Stabilization Effect of CO₂ in the Electrochemical Hydrogenation of Azo Compounds and the Reductive Coupling of α‐Ketoesters

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

Published: Oct. 7, 2022

The carbon dioxide (CO2 ) capture and utilization has attracted a great attention in organic synthesis. Herein, an unpresented transient stabilization effect (TSE) of CO2 is disclosed well applied to the electrochemical hydrogenation azo compounds hydrazine derivatives. Mechanistic experiments computational studies imply that can radical anion intermediates protect from potential degradation reactions, finally released through decarboxylation. promotion was further demonstrated work preliminary study reductive coupling α-ketoesters vicinal diol For reactions mentioned above, indispensable. presented results shed light on different usage could inspire novel experimental design by using as protecting group.

Language: Английский

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One‐Pot Synthesis of Aldehydes or Alcohols from CO₂ via Formamides or Silyl Formates

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(6), P. 877 - 883

Published: March 1, 2023

The solvent-free N-formylation of 2-(methylamino)pyridine with CO2 and phenylsilane was catalyzed by Cu(OAc)2 alone to give N-methyl-N-(2-pyridyl)formamide called Comins-Meyers formamide. X-ray crystallographic analysis a copper complex revealed paddle-wheel structure consisting two ions bridged four acetate molecules on both axial sites, which suggested (i) the improved solubility ion (ii) enhanced nucleophilicity for activation phenylsilane. 1H NMR spectra benzene-d6 solutions containing Cu(OAc)2, 2-(methylamino)pyridine, showed singlet signal at 2.62 ppm, assigned catalytically active Cu−H species, this disappeared upon exposure CO2. formamide synthesized from via copper-catalyzed hydrosilylation under conditions directly subjected Grignard reactions in THF one-pot synthesis aldehydes or alcohols. On other hand, silyl formates prepared using tetrabutylammonium (TBAA) as an organocatalyst were also found be good precursors As service our authors readers, journal provides supporting information supplied authors. Such materials are peer reviewed may re-organized online delivery, but not copy-edited typeset. Technical support issues arising (other than missing files) should addressed Please note: publisher is responsible content functionality any Any queries content) directed corresponding author article.

Language: Английский

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An Oxidative [3+2+1] Cyclization of Enaminones and N‐Alkenyl‐2‐pyrrolidinone: Access to Polysubstituted 4‐Alkylated 1,4‐dihydropyridines

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(8), P. 1217 - 1223

Published: March 25, 2023

Abstract An oxidative [3+2+1] cyclization of enaminones and N ‐alkenyl‐2‐pyrrolidinone is described for the synthesis 4‐alkylated 1,4‐dihydropyridines (1,4‐DHPs). By using terminal olefin as C4 source 1,4‐DHP skeleton, this synthetic strategy provides a series 1,4‐DHPs through 1,1‐difunctionalization/cyclization process. In protocol, two C( sp 3 )−C( 2 ) bonds )−N bond are simultaneously formed, hydrogen on newly formed methyl group skeleton confirmed possible mechanism proposed. magnified image

Language: Английский

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Skeletal Formation of Carbocycles with CO₂: Selective Synthesis of Indolo[3,2-b]carbazoles or Cyclophanes from Indoles, CO₂, and Phenylsilane

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(22), P. 14935 - 14941

Published: May 9, 2024

The catalytic reactions of indoles with CO2 and phenylsilane afforded indolo[3,2-b]carbazoles, where the fused benzene ring was constructed by forming two C–H bonds four C–C molecules via deoxygenative conversions. Nine-membered cyclophanes made up three were also obtained, cyclophane framework six bonds. These multicomponent cascade giving completely different carbocycles switched simply choosing solvent, acetonitrile or ethyl acetate.

Language: Английский

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