Synthesis Of Enaminones Research Articles

Efficient Synthesis of a Series of Novel Octahydroquinazoline-5-ones via a Simple on-Water Urea-Catalyzed Chemoselective Five-Component Reaction.

Multicomponent reactions (MCRs) have become a powerful tool for drug discovery and development owing to their advantages of fast and efficient construction of a large library of products with complexity and diversity. However, conventional MCRs usually proceed in environmentally unfriendly organic solvents rather than in water, a green solvent used by nature for biological chemistry. Herein, a simple and efficient on-water urea-catalyzed chemoselective five-component reaction (5CR) has been developed for the synthesis of a series of novel octahydroquinazoline-5-ones (6), the derivatives of quinazolinones possessing diverse biological activities. The molecular structure of 6{1,1,12} has been confirmed by single-crystal X-ray diffraction. The 5CR can proceed at room temperature under normal atmospheric pressure in good yields and afford a large library of octahydroquinazoline-5-ones with various aromatic and aliphatic substituents at N-1, C-2, and N-3. In addition, a green method has been developed for the synthesis of enaminones, important intermediates in the 5CR and in synthetic chemistry.

Transition-metal-free solid phase synthesis of 1,2-disubstituted 4-quinolones via the regiospecific synthesis of enaminones

The transition-metal-free economical solid phase synthesis of 1,2-disubstituted 4-quinolones has been developed via the novel regiospecific synthesis of enaminones.

ChemInform Abstract: Synthesis of Enaminones and Their Difluoroboron Complexes Through Domino Aryl Migration.

AbstractThis new domino strategy allows the selective synthesis of boron complexes.

ChemInform Abstract: Enaminones via Ruthenium‐Catalyzed Coupling of Thioamides and α‐Diazocarbonyl Compounds.

AbstractThe use of Ru(II) catalysts, which are less expensive than the established Rh2(OAc)4, for the synthesis of enaminones via coupling of α‐diazocarbonyl compounds with thioamides is described.

Enaminone Complexes: Synthesis, Characterization and Bioactivity

Synthesis of enaminones, viz., 3-(dimethylamino)-1-(thiophen-2-yl)prop-2-en-1-one and 3-(dimethylamino)-1-phenylprop-2-en-1-one, and their chelating with different metal nitrates of Cu 2+ , Ni 2+ , Hg 2+ , Pb 2+ and Co 2+ in ethnolic solution were reported. The bioactivity of ligands and metal complexes against eight types of bacteria and three types of fungi were investigated.

Synthesis of enaminones and their difluoroboron complexes through domino aryl migration.

A new domino strategy for selective synthesis of enaminones and their difluoroboron complexes through aryl migration has been developed. The reaction features low-cost and readily accessible starting materials, reliable scalability, and bond-forming efficiency as well as simple one-pot operation, which makes this strategy highly viable for future applications.

ChemInform Abstract: A New Method for the Enamination of 1,3‐Dicarbonyl Compounds Catalyzed by Laccase in Water.

A new method for the enamination of 1,3-dicarbonyl compounds catalyzed by laccase in water is described for the first time. Besides providing a green and efficient method for the synthesis of enaminones, this study extends the applicability of laccase in organic synthesis.

Four‐Component Synthesis of β‐Enaminone and Pyrazole through Phosphine‐Free Palladium‐Catalyzed Cascade Carbonylation

AbstractThe carbonylative domino synthesis of enaminones and pyrazoles has been performed with the NN bidentate palladium catalyst to achieve excellent selectivity. These results have confirmed that the carbonylative Sonogashira coupling of iodobenzenes with terminal alkynes is accompanied by the Michael addition of amines or phenylhydrazine in a one‐pot method, which generates the desired products. This protocol demonstrates wide substrate tolerance, including hitherto unused aromatic amines, to yield the corresponding pure aromatic β‐enaminones, which are subsequently converted into the 3‐acylindole derivatives under mild conditions.

Enaminones via ruthenium-catalyzed coupling of thioamides and α-diazocarbonyl compounds.

Enaminones can be prepared via the Rh2(OAc)4-catalyzed coupling of α-diazocarbonyl compounds with thioamides. However, rhodium is the most expensive and least abundant among the dominant precious metals used for catalysis. Furthermore, a very limited substrate scope is known for the intermolecular rhodium catalyzed coupling reaction. Therefore, there is a need to find a more economical catalyst substitute with a broad substrate scope. In this paper, we describe the use of Ru(II) catalysts for the synthesis of enaminones. The reaction can be performed efficiently with the Grubbs first-generation catalyst or [(Ph)3P]3RuCl2 in a sealed tube. Both catalysts are much less expensive than Rh2(OAc)4. Secondary and tertiary thioamides, when reacted with α-diazodiesters, α-diazoketoesters, α-diazodiketones, and α-diazomonoketones give enaminones. Primary thioamides give thiazole derivatives when reacted with α-diazomonoketones. However, with other diazo compounds, primary thioamides also give enaminones. All enaminones are obtained in good yields and with good diastereoselectivity. Accordingly, the method described in this paper is an efficient and economical alternative to the Rh2(OAc)4-catalyzed coupling process.

ChemInform Abstract: Polyfluoro‐ and Perfluoroalkoxyenaminones in Syntheses of Nitrogen Containing Heterocycles.

AbstractA simple method for the synthesis of enaminones (III) with poly‐ and perfluoroalkoxy groups at the 2‐position is developed.

Nano Fibrous Silica Sulphuric Acid as an Efficient Catalyst for the Synthesis of β-Enaminone

Synthesis of KCC-1 silica sulphuric acid as a new catalyst has been reported. The catalyst was characterized using XRD, SEM, TEM, BET, FT-IR, TGA-DTA, and EDX analysis. The catalytic activity was evaluated for the synthesis of enaminones under solvent-free conditions. The catalyst was easily recovered and reused up to seven cycles with slight loss of activity. The attractive features of this protocol are low amount of catalyst loading, short reaction time, mild reaction conditions, good to excellent yield of the products, easy handling of the catalyst and simple operational procedure. A highly efficient Sulphated nanosilica sulphuric acid has been synthesized and applied for the synthesis of enaminones. This catalytic protocol is better for the synthesis of enaminone than previously reported procedures in terms of catalyst loading, reaction condition, reaction time and yields of the products.

Green Synthesis of Enaminones Catalyzed by ZSM-5

It was found that ZSM-5 as a green catalyst could efficiently catalyze the reaction of various primary amines with α,β-dicarboxyl compounds to afford β-enaminones in good yields at room temperature. The method provides a novel, simple and convenient route to substitute β-enaminones from primary amines and α,β-dicarboxyl compounds. The catalyst could also be recovered easily. Keywords catalysis; β-enaminones; ZSM-5 zeolite

K-10 clay as a reusable catalyst for the solvent-free MW-induced synthesis of enaminones

A series of ?-amino-?, ?-unsaturated ketones and esters synthesized from the reaction of different amines with 1,3- dicarbonyl compounds in solvent-free media using montmorillonite K-10 clay as solid recyclable heterogeneous acidic catalyst and microwave irradiation in good to excellent yields.

ChemInform Abstract: Water‐Promoted Synthesis of Enaminones: Mechanism Investigation and Application in Multicomponent Reactions.

AbstractAn efficient and green approach for the highly stereoselective synthesis of (Z)‐enaminones (III) is given.

ChemInform Abstract: Acetylide Ion(C22‐) as a Synthon to Link Electrophiles and Nucleophiles: A Simple Method for Enaminone Synthesis.

AbstractThe three‐component reaction of aryl aldehyde, calcium carbide and a bulky secondary amine provides a direct synthesis of enaminones (IV).

ChemInform Abstract: Copper‐Catalyzed Aldol‐Type Addition of Ketones to Aromatic Nitriles: A Simple Approach to Enaminone Synthesis.

AbstractThe reaction proceeds smoothly under mild conditions using readily available starting materials.

Water-Promoted Synthesis of Enaminones: Mechanism Investigation and Application in Multicomponent Reactions

Highly stereoselective synthesis of Z-enaminones bearing reactive secondary amino group has been successfully performed in water using tertiary amino group functionalized enaminones under ambient conditions. An interesting promotion effect of water on the reaction via hydrolysis–dehydration condensation has been observed through a designed isotope labeling experiment. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.

ChemInform Abstract: A General and Efficient Method for Synthesis of Enaminones and Enamino Esters Catalyzed by NbCl5 under Solvent‐Free Conditions.

AbstractNbCl5 catalyzes the synthesis of enaminones and enamino esters from the corresponding 1,3‐dicarbonyl compounds and primary amines under solvent‐free conditions.

ChemInform Abstract: Ring Expansion and Rearrangements of Rhodium(II) Azavinyl Carbenes.

AbstractA selective, rapid, scalable, simple synthesis of enaminones and olefins by ring expansion and rearrangement reactions is presented.

Acetylide Ion (C22−) as a Synthon To Link Electrophiles and Nucleophiles: A Simple Method for Enaminone Synthesis

Freundliche Konkurrenten: Ein Dreikomponentensystem aus Calciumcarbid, einem Arylaldehyd und einem Amin liefert über konkurrierende Reaktionswege auf vorhersagbare Weise Enaminone oder Propargylamine (siehe Bild). Das System ermöglicht die effiziente Synthese einer Vielzahl von Enaminonen aus einfach zugänglichen Ausgangsverbindungen und demonstriert die Vielseitigkeit des Acetylid-Ions beim Verknüpfen von Elektrophilen mit Nucleophilen. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.