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The base promoted three-component reaction of β-enamino imide, malononitrile and various cyclic α-diketones in acetonitrile showed interesting molecular diversity. The reactions with acenaphthylene-1,2-dione and ninhydrin afforded functionalized spiro[indene-2,4'-pyrrolo[3,4- b]pyridines] and spiro[acenaphthylene-1,4'-pyrrolo[3,4- b]pyridines] in good yields. The similar reaction of phenanthrene-9,10-dione resulted in the formation of the unexpected complex phenanthro[9',10':4,5]furo[2,3- c]pyrrolo[3,4- b]pyrroles in satisfactory yields. [ABSTRACT FROM AUTHOR]

The novel 1,2-diaryl substituted pyrrolo[3,4- b]pyridine-5,7-diones were selectively synthesized in high yields by the base catalyzed cyclization reaction of 3-arylamino-1-methyl-1 H-pyrrole-2,5-diones with cinnamaldehyde and its derivatives in acetonitrile at room temperature. However, when piperidinium trifluoroacetate was employed as catalyst, the reaction afforded a mixture of 1,2-diaryl and 1,4-diaryl substituted pyrrolo[3,4- b]pyridine-5,7-diones in comparable yields. [ABSTRACT FROM AUTHOR]

The base mediated cycloaddition reactions of 4-dimethylamino-1-phenacylpyridinium bromides with two molecular 3-phenacylideneoxindoles in methylene dichloride afforded functionalized dispirocyclopentyl-3,3′-bisoxindoles in good yields and with high diastereoselectivity. The similar cycloaddition reactions of 1-( N, N-dialkylcarbamoylmethyl) and 1-cyanomethyl 4-dimethylamino-pyridinium bromide in refluxing ethanol in the presence of triethylamine also resulted in dispirocyclopentyl-3,3′-bisoxindoles with high diastereoselectivity. The stereochemistry of dispirocyclopentyl-3,3′-bisoxindoles was elucidated on the basis of 1H NMR data and single crystal structures. [ABSTRACT FROM AUTHOR]

The three-component reaction of N-phenacylbenzothiazolium bromides, aromatic aldehydes and indane-1,3-dione in ethanol at room temperature in the presence of triethylamine as base afforded functionalized spiro[benzo[ d]pyrrolo[2,1- b]thiazole-3,2′-indenes] in good yields and with high diastereoselectivity. The 1H NMR data and single crystal structure clearly indicated that the obtained spiro compounds predominately have one diastereoisomer. [ABSTRACT FROM AUTHOR]

The novel spirooxindoline fused [1,3]oxazines were efficiently synthesized from Diels-Alder reaction of N-arylmaleimides with 1,2-dihydro-2-oxospiro[3 H-indole-3,2′-[2 H,9a H-pyrido[2,1- b][1,3]oxazines], which were generated in situ from three-component reactions of substituted pyridines and isatins with methyl propiolate, or dimethyl acetylenedicarboxylate. The stereochemistry of the products was clearly clarified by the analysis of 1H NMR data and single crystal structures of the obtained polycyclic compounds. [ABSTRACT FROM AUTHOR]

In this work, a novel and simple flexible aromatic multi-carboxylate compound N, N′-(4,4′-biphenylyl) iminodiacetic acid (BP-IDA) was synthesized, with which two new stable metal-IDA gels (denoted as MIG1 and MIG2) with three-dimensional network structures have been prepared successfully by employing Cr3+ and Al3+ as the metal ions, respectively. The rheological performance was investigated by means of dynamic rheology measurement. The morphology and microstructure were characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction technique. Nitrogen sorption isotherm measurement suggests that the MIG1 aerogel has considerable porosity with the Brunauer-Emmett-Teller specific surface area up to 760 m2·g−1. Owing to easy preparation, good stability, and three-dimensional network structure, the as-prepared metal-organic gels will possess potential applications in separation, catalysis, and drug delivery. [ABSTRACT FROM AUTHOR]

The one-pot four-component reaction of benzohydrazide, acetylenedicarboxylate, aromatic aldehydes and malononitrile in ethanol with triethylamine as base catalyst afforded functionalized 1-benzamido-1,4-dihydropyridines in satisfactory yields. Under similar conditions, picolinohydrazide or nicotinohydrazide can also be successfully utilized in the reactions to give corresponding functionalized 1,4-dihydropyridines. 1H NMR data indicated that an equilibrium of cis/trans-conformations exist in 1-benzamido-1,4-dihydropyridines. [ABSTRACT FROM AUTHOR]