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A green one-pot reaction involving cyclic secondary amines, activated alkynes, and alloxan derivatives in water has been established, offering a cost-effective and selective route to (enamino)hydroxybarbiturates and 3-amino-5-hydroxycyclopent-2-enone-derived carbonylureas with high yields. This method utilizes readily available starting materials to produce valuable compounds for medicinal chemistry and organic synthesis through a three-component cascade reaction under mild conditions. [Display omitted] • The regioselective green synthesis of cyclopent-2-enone-derived carbonylureas and enaminohydroxybarbiturates is reported. • Bisfunctionalization of alloxan ring in water at room temperature. • Readily available starting materials, and biological significance of the products. • High bond efficiency of producing three new bonds (two C-C and one C-N). [ABSTRACT FROM AUTHOR]

The highly reactive alkylaminofurochromenone intermediate, produced from the reaction between 3-formylchromones and alkyl isocyanides, was trapped by monocyclic unsaturated acyl compounds such as maleic anhydride or maleimide derivatives to yield new types of organic fluorophores 4-(alkylamino)-1 H -furo[3,4- b ]xanthene-1,3,10-triones or 4-(alkylamino)chromeno[2,3- f ]isoindole-1,3,10(2 H )-triones, which exhibited strong sky blue emission in solution. The reaction is very simple from an experimental point-of-view and allows the creation of a fused benzene ring with concomitant formation of three new C–C bonds in a single operation. [ABSTRACT FROM AUTHOR]

A novel protocol was developed for the synthesis of alkyl [2-[(cyclohexylamino)carbonyl]-4-oxo-2 H -chromen-3(4 H )-ylidene]methyl 3,4,5,6-tetrahalophthalate derivatives via the one-pot, four-component domino O -acylation/α-addition cyclization/alcoholysis reaction of tetrahalophthalic anhydrides, 3-formylchromones, cyclohexyl isocyanide and various alcohols. The highlights of this novel cascade reaction include mild reaction conditions, easy workup, and high bond efficiency resulting in the formation of four new bonds (two C O, one C O and one C C) in a single operation. [ABSTRACT FROM AUTHOR]

A series of diverse polycyclic heterocycles containing 3-hydroxyoxindole, and alkyliminofurochromone fused rings have been synthesized through the uncatalyzed Friedel-Crafts hydroxyalkylation of 3-(alkylamino)-9 H -furo [3,4-b]chromen-9-ones generated in situ by the [4 + 1] cycloaddition/tautomerization of alkyl isocyanides and 3-formylchromones with isatin derivatives. The method is simple and provides a new class of pharmacologically important furochromone-isatin conjugates in moderate to good yields. The products bearing two contiguous stereogenic centers and one stereogenic group were obtained in excellent diastereoselectivities. [ABSTRACT FROM AUTHOR]

Abstract: A three-component domino reaction between a 3-formylchromone, an isocyanide, and 1,3-dimethylalloxan which affords novel 5-(furo[3,4-b]chromenyl)-5-hydroxybarbiturate derivatives is reported. The reaction sequence consists of an initial [4+1] cycloaddition followed by an activated electrophilic heteroaromatic substitution on the furan ring to afford the products. This novel cascade reaction sequence represents an atom-economic route to biologically interesting molecules. [Copyright &y& Elsevier]

Abstract: An efficient, safe and facile route to functionalized spiro[furo[2,3-d]pyrimidine-6,5′-pyrimidine] derivatives has been developed by a one-pot pseudo three-component domino coupling of aromatic aldehydes and (thio)barbituric acids in the presence of urotropine–bromine (UB) complex in water at room temperature. The reaction sequence consists of an initial Knoevenagel condensation of aromatic aldehydes with (thio)barbituric acids, followed by Michael addition of the second equivalent of (thio)barbituric acid derivatives, and then UB-catalyzed Williamson cycloetherification to afford the products. [Copyright &y& Elsevier]

Abstract: A simple and efficient one-pot synthesis of novel ferrocene–triamide conjugates from the reaction of ferrocenecarboxaldehyde with Meldrum’s acid and isocyanides in the presence of NH-containing compounds is described. This transformation proceeds through the creation of two Ctwo Cand one Ceading to three peptide bonds, and presumably occurs via a domino sequence involving Knoevenagel condensation, [1+4] cycloaddition, deacetonation, and aminolysis reactions. [Copyright &y& Elsevier]

Abstract: The reactions of 3-formylchromones with alkyl isocyanides in dry dichloromethane at room temperature lead to new types of organic fluorophores (1Z)-3-(alkylimino)-1-[(chromone-3-yl)methylene]-1,3-dihydro-9H-furo[3,4-b]chromen-9-one, which exhibited strong blue emission in solution. The reactions involve a [4+1] cycloaddition followed by an activated electrophilic aromatic substitution at the furan ring and dehydration sequence. [Copyright &y& Elsevier]

Abstract: A three-component domino reaction approach between a primary amine, a dialkyl acetylenedicarboxylate, and 1,3-dimethylalloxan that affords novel oxaspirobicyclic γ-butenolidobarbiturate derivatives is reported. The reaction sequence consists of an initial Michael-addition of primary amines to dialkyl acetylenedicarboxylates, followed by aldol-like reaction with 1,3-dimethylalloxan, and then γ-lactonization to afford the products. This cascade reaction sequence represents a rapid and unprecedented route to the described biologically interesting molecules. [Copyright &y& Elsevier]

Abstract: Protonation of the highly reactive 1:1 intermediate produced in the reaction between alkyl or aryl isocyanides and electron-deficient acetylenic esters with 3,6-dihydroxypyridazine, leads to a vinylisonitrilium cation, which undergoes an addition reaction with the conjugate base of the 3,6-dihydroxypyridazine to produce dialkyl 3-(alkyl or arylamino)-5,8-dioxo-5,8-dihydro-1H-pyrazolo[1,2-a]pyridazine-1,2-dicarboxylates in good yields at room temperature. [Copyright &y& Elsevier]

Abstract: Some novel spiro-oxazinobarbiturate derivatives have been successfully synthesized in a one-pot, three-component cascade reaction from various azines (pyridine, isoquinoline, quinoline and phenanthridine), 1,3-dimethylalloxan, and several activated acetylenes (alkyl propiolates, dialkyl acetylenedicarboxylates, and butyne-2-one). The high bond forming efficiency (formation of new C–N, C–C, and C–O bonds) of this reaction makes it attractive for the synthesis of spiro-oxazinobarbiturates in a single operation. [Copyright &y& Elsevier]

Xanthoquinones, as a new class of quinone dyes comprising the xanthone and quinone subunits have been synthesized. An elusive aminofurochromone as an electron-rich diene was generated in situ from the corresponding chromone-3-carbaldehyde and alkyl or aryl isocyanide via a formal [4 + 1] cycloaddition reaction, then engaged by p -quinone partner (1,4-benzoquinone or 1,4-naphthoquinone) as an electron-deficient dienophile to afford the desired novel xanthoquinone dye via a [4 + 2] cycloaddition/ring opening/dehydrative aromatization sequence. [Display omitted] • A facile one-pot three-component protocol for the synthesis of novel xanthoquinone dyes is reported. • Mild and metal-free reaction. • Readily available starting materials, and photophysical significance of the products. • High bond-forming efficiency of producing three new C–C bonds in creation of a fused benzene ring. [ABSTRACT FROM AUTHOR]

Abstract: A water-accelerated multicomponent synthesis of organic target molecules has been used as a key method for the preparation of novel barbiturate derivatives. The three-component condensation reactions of primary amines with alkyl propiolates in the presence of alloxan derivatives in water are developed as efficient and clean green synthetic procedures for the high-yielding preparation of alkyl 2-(5-hydroxy-2,4,6-trioxohexahydro-5-pyrimidinyl)-3-(alkyl or arylamino)-2-propenoates. The above synthetic protocol provides rapid access to novel and diversely substituted barbiturate derivatives. [Copyright &y& Elsevier]

Abstract: The regioselective three-component condensation reaction of 2-hydroxy-1,4-naphthoquinone with isocyanides in the presence of a variety of aldehydes offers an easy one-pot access to linear naphtho[2,3-b]-furan-4,9-dione derivatives. This method has the advantage of good yields, high regioselectivity, and uses readily accessible substrates and reagents. The elucidation of regiochemistry has been accomplished by X-ray determination of some representative compounds. [Copyright &y& Elsevier]

Abstract: Protonation of the highly reactive 1:1 intermediate produced in the reaction between alkyl isocyanides and electron-deficient acetylenic esters with phthalhydrazide, leads to a vinylisonitrilium cation, which undergoes an addition reaction with the conjugate base of the phthalhydrazide to produce dialkyl 3-(alkylamino)-5,10-dioxo-5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine-1,2-dicarboxylates in fairly good yields at room temperature. [Copyright &y& Elsevier]

Abstract: A simple and efficient synthesis of 1,4-bis(furo[2,3-d]pyrimidine-2,4(1H,3H)-dione-5-yl)benzene derivatives was achieved via a one-pot three-component reaction of isocyanides, N,N′-dimethylbarbituric acid, and terephthaldialdehyde in DMF at room temperature for 30min. These improved reaction conditions allow the preparation of highly substituted furopyrimidinones in high yields and purity under mild reaction conditions. [Copyright &y& Elsevier]

Abstract: The highly reactive 1:1 adduct, produced from the reaction between dialkyl acetylenedicarboxylates and alkyl isocyanides, was trapped by strong cyclic CH-acids such as 4-hydroxy-6-methyl-2H-pyran-2-one or 4-hydroxycoumarin to yield dialkyl 2-(alkylamino)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3,4-dicarboxylates or dialkyl 7-methyl-2-(alkylamino)-5-oxo-4H,5H-pyrano[4,3-b]pyran-3,4-dicarboxylates in good yields at room temperature. [Copyright &y& Elsevier]

Abstract: The highly reactive 1:1 adduct, produced from the reaction between dialkyl acetylenedicarboxylates and alkyl isocyanides, was trapped by benzoyl cyanide derivatives to afford dialkyl 5-alkylimino-2-cyano-2-aryl-2,5-dihydro-3,4-furandicarboxylates in fairly good yields. [Copyright &y& Elsevier]

The environment-friendly three component condensation reactions of N,N′-dimethylbarbituric acid, 4-nitrobenzaldehyde and alkyl or aryl isocyanides to afford the corresponding furo[2,3-d]pyrimidine-2,4(1H,3H)-diones, in water, in high yields after several minutes are reported. [Copyright &y& Elsevier]

An efficient protocol for the selective synthesis of (acyloxymethylidene)chromonyl-furochromones or amido-(acyloxymethylidene)chromones via a water-controlled multicomponent cascade reaction of 3-formylchromones, linear carboxylic acid anhydrides, and alkyl isocanides in CH 2 Cl 2 has been developed. (Acyloxymethylidene)chromonyl-furochromones were obtained in dry CH 2 Cl 2 ; conversely, amido-(acyloxymethylidene)chromones were formed with wet CH 2 Cl 2 (undried dichloromethane) as the solvent at room temperature. The reaction proceeds via the formation of a highly reactive O -acylatedoxonium intermediate, generated from the reaction between 3-formylchromones and linear carboxylic acid anhydrides. The subsequent trapping of the O -acylatedoxonium ion by aminofurochromone intermediate in situ generated by cycloaddition reaction of alkyl isocyanide and the second equivalent of 3-formylchromone in dry CH 2 Cl 2 , would give (acyloxymethylidene)chromonyl-furochromones in excellent diastereoselectivity and yields. Alternatively, O -acylatedoxonium intermediate could be also regioselectively trapped by α-addition of alkyl isocyanides in wet CH 2 Cl 2 to provide amido-(acyloxymethylidene)chromones in good yields. [Display omitted] [ABSTRACT FROM AUTHOR]