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Abstract: A novel synthetic method of carbohydrate derived vicinal aminoalcohols, from sugar aldehydes and bromonitroalkanes, has been developed. It involves an indium-catalyzed one-pot Henry reaction and nitro group reduction, and proceeds with a remarkably high anti-selectivity. The reaction of the intermediate aminoalcohols with alkylating agents furnished the corresponding carbohydrate-based tertiary aminoalcohols with excellent stereoselectivity. This very simple methodology allows easy access to families of N,N-dialkylated vicinal aminoalkanols, useful intermediates in the synthesis of derivatives of biological interest and sugar-based stereodifferentiating agents for asymmetric catalysis. [Copyright &y& Elsevier]

Abstract: The Diels–Alder reaction of (E)-2-styrylchromones with a pyrimidine ortho-quinodimethane is reported for the first time. These cycloaddition reactions afford mixtures of two regioisomeric tetrahydroquinazoline-substituted chromones in moderate to excellent global yields. Irrespective of the substituents on the 2-styrylchromones, the 2-(7-aryl-4-methoxy-2-methyl-5,6,7,8-tetrahydroquinazolin-6-yl)chromone derivatives are always the major isomers. [Copyright &y& Elsevier]

Abstract: A simple synthesis of new amphiphilic chlorin derivatives from protoporphyrin-IX dimethyl ester is reported. The preparation of such compounds is based in a straightforward methodology, which involves the Diels–Alder reaction of protoporphyrin-IX dimethyl ester with maleic anhydride followed by addition of nucleophilic species to the initially formed cycloadducts, a transformation, which is highly regioselective. Preliminary photophysical studies with the new compounds show that they meet adequate features for PDT applications. [Copyright &y& Elsevier]

A two-step procedure transformation starting from the reaction of ortho -phenylenediamines on 2-acetylbutyrolactone 1 yielded ( Z )-3-(1-aminoethylidene)butyrolactones 2 , which were treated with either N , N -dimethylformamide dimethyl acetal, triphosgene, or carbon disulfide under different reaction conditions to produce a new series of benzimidazole–, benzimidazolone–, or benzimidazole-2-thione–butyrolactone dyads 3 – 5 , respectively. The structures of compounds 2 – 5 were established by NMR and mass spectrometry. The isolation of important reaction intermediates as single-crystals allowed the determination of the ( Z )-configuration in the resulting conjugate heterocyclic systems 3 – 5 by X-ray diffraction studies. [ABSTRACT FROM AUTHOR]

Abstract: New methods for the synthesis of (E)-3-halo-2-styryl-4H-chromen-4-ones were established. The reaction of these compounds with hydrazine hydrate afforded new and unexpected 3(5)-aryl-5(3)-[2-(2-hydroxyphenyl)-2-hydrazonoethyl]-1H-pyrazoles, which upon acid hydrolysis gave 3(5)-aryl-5(3)-[2-(2-hydroxyphenyl)-2-oxoethyl]-1H-pyrazoles. The reaction mechanisms for these transformations, involving 1,6- followed by 1,4-conjugate additions, are discussed and the structures of all new compounds were established by NMR studies. [Copyright &y& Elsevier]

Abstract: We report the synthesis of novel 2H,8H-pyrano[2,3-f]chromene-2,8-dione based scaffolds by the reaction of 8-formyl-7-hydroxy-4-methylcoumarin with various active methylene compounds. A mechanism of a tandem Knoevenagel condensation and cyclisation reaction is proposed. The structure of all compounds was established on the basis of 1H and 13C NMR data, high resolution mass spectrometry and elemental analysis. [Copyright &y& Elsevier]

Abstract: New porphyrin/4-quinolone conjugates were synthesized from the Suzuki–Miyaura coupling reaction of a β-borylated porphyrin with bromo-4-quinolones containing N-ethyl and N-d-ribofuranosyl substituents. The use of electrospray ionization tandem mass spectrometry showed important information about the fragmentation pathways of the new compounds. It was possible to distinguish between those compounds with the porphyrin moiety linked at the 6-position of the quinolone unit from their 7-substituted isomers. The new compounds showed to be good singlet oxygen generators. [Copyright &y& Elsevier]

Abstract: The catalytic insertion of ethyl diazoacetate into a porphyrin derivative bearing an NH2 substituent, in the presence of a Rh-based catalyst, was investigated. The X-ray analysis of one of the isolated products reveals the formation of a chiral supramolecular system. [Copyright &y& Elsevier]

Abstract: Two new anthocyanin-derived compounds corresponding to the ethylpyranomalvidin-3-glucoside and the pyranomalvidin-3-glucoside dimer linked through a methyl-methine bridge were synthesized for the first time and their structure characterized by LC-DAD/MS and NMR spectroscopy. The latter was obtained in a hydroalcoholic model solution through the reaction of the carboxypyranomalvidin-3-glucoside with ethylpyranomalvidin-3-glucoside and displays a blue/green color in solution. [Copyright &y& Elsevier]

Abstract: 5,10,15-Tris(pentafluorophenyl)corrole slowly undergoes oligomerization when left in solution at room temperature, under air and ambient light. This transformation was studied in different solvents (chloroform, dichloromethane, and toluene) and the main resulting products were identified as the 3,3′-corrole dimer 2a and the 3,3′,17′,3′′-corrole trimer 3a. [Copyright &y& Elsevier]

Abstract: Sapphyrins participate in Diels–Alder reactions with pentacene affording novel barrelene-fused sapphyrins. The new compounds were synthesized using traditional heating and microwave irradiation conditions. The experiments carried out under microwave irradiation proved cleaner, affording only the monoadduct and in higher yields. [Copyright &y& Elsevier]

Abstract: Porphyrinic pyridinium ylides react with 1,4-benzoquinone and 1,4-naphthoquinone to afford novel meso-substituted indolizine porphyrins. [Copyright &y& Elsevier]