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An efficient, facile, and clean synthesis of various 3‐hydroxy‐chromones (3‐hydroxy‐4H‐chromene‐4‐ones) via enamino ketone followed by cyclization using m‐chloroperbenzoic acid (MCPBA) has been described. The significant features of this method include simple method, high purity and excellent regio‐selectivity of the products. This is the first report for the two step one pot synthesis of 3‐hydroxyl chromone using MCPBA. [ABSTRACT FROM AUTHOR]

An efficient and novel method for the preparation of N-aryl-quinolone via enaminone synthesis has been described. Subsequent derivatization at 3 position has been accomplished by the palladium catalyzed Suzuki cross coupling reaction. Using this method, various aryl boronic acids as well as hetero aryl boronic acids have been coupled with 3-bromoquinolone to generate the novel 1,3-di-aryl-quinolone derivatives. The key step quinolone ring formation has been achieved by intramolecular displacement reaction of enaminone 2 with suitably substituted ortho-fluoro group in the aromatic ring. [ABSTRACT FROM AUTHOR]

A new regioselective method for the synthesis of 3-(methylthio)-4H-chromen-4-one and 3-(phenylthio)-4H-chromen-4-one derivatives has been developed. The reaction between o-hydroxy-phenyl-functionalized enaminones and methylsulfinyl derivatives using T3P® gave good yields of chromone thioether derivatives. The reaction proceeds via domino chromone ring construction and C(sp2)–H bond sulfenylation under transition-metal-free conditions. [ABSTRACT FROM AUTHOR]

An efficient synthesis of 4H-chromene-4-ones via enamino ketones, with cyclization by using T3P® under microwave heating is described. This is the first report for the synthesis of chromones by using T3P®. Significant features of this method include short reaction times and high-purity products. [ABSTRACT FROM AUTHOR]

An efficient method for the preparation of chromone based $$\upalpha $$ -amino acid derivatives by alkylation of glycinate schiff base with 3-bromomethyl chromone as well as 2-bromomethyl chromone has been described. Using this method, 2-amino-3-(4-oxo-2-chromenyl)propanoic acid and 2-amino-3-(4-oxo-3-chromenyl)propanoic acid, two novel chromone-amino acid conjugates have been prepared. Furthermore, the separation of chromone amino acid enantiomers by chiral column chromatography was accomplished. Graphical Abstract : Synopsis: An efficient method for the preparation of chromone based $$\upalpha $$ -amino acid derivatives by alkylation of glycinate schiff base with 3-bromomethyl chromone as well as 2-bromomethyl chromone has been described. These conjugates can be considered as analogues of phenyl alanine where phenyl group has been replaced by chromone moiety. [ABSTRACT FROM AUTHOR]

A new series of isoxazole tethered quinone-amino acid hybrids has been designed and synthesized involving 1,3-dipolar cycloaddition reaction followed by an oxidation reaction using cerium ammonium nitrate (CAN). Using this method, for the first time various isoxazole tethered quinone-phenyl alanine and quinone-alanine hybrids were synthesized from simple commercially available 4-bromobenzyl bromide, propargyl bromide, and 2,5-dimethoxybenzaldehyde in good yield. [ABSTRACT FROM AUTHOR]