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A two step sequence involving Ugi reaction followed by reductive Heck cyclization has been evaluated in order to provide access to a 3-benzazepine framework in a diversity-oriented fashion. Several aspects related to the substrate scope and the optimal distribution of the required functional groups have been addressed, resulting in the construction of a small library of the title compounds, featuring four distinct types of substitution pattern. [ABSTRACT FROM AUTHOR]

Abstract: An efficient base-promoted 3-alkylation of 3,5-dichloro-2(1H)-pyrazinones with various malonate esters is described. The method constitutes a simple example of a C–C bond forming process at the 3-position of the pyrazinone core allowing to attain 3-substituted pyrazinones in good to high yields. 3-Alkylation of 3,5-dichloro-2(1H)-pyrazinones with acetoacetic ester was accompanied by further retro-Claisen fragmentation. [Copyright &y& Elsevier]

[Display omitted] • • A transition metal-free strategy for the synthesis of cyclic sulfamides was developed. • • Orthogonal deprotection and side chain post-modification via a saponification/amide coupling sequence were implemented. • • The synthesized compounds showed inhibitory activity against human carbonic anhydrase isoform II (hCA II). A straightforward and transition metal-free method for the synthesis of cyclic sulfamides via base-promoted bis-alkylation of tert -butyl (N -alkylsulfamoyl)carbamates with electron-deficient allyl bromides is described. All obtained cyclic sulfamides underwent successful removal of tert -butoxycarbonyl protecting group. [ABSTRACT FROM AUTHOR]

[Display omitted] 4-Bromo-1 H -indole-3-carbaldehyde has been explored as a key building block for a post-Ugi assembly of azepino[3,4,5-cd]indoles and spiroindolines. First, the corresponding Ugi adducts were successfully employed in palladium-catalyzed reductive Heck cyclization producing a range of azepinoindoles. Then, 4-bromo-1 H -indole-3-carbaldehyde-derived Ugi adducts were subjected to cationic gold catalysis affording tetracyclic spiroindolines. Furthermore, the aryl bromide moiety retained in the resulting spiroindolines was found to be amendable to further functionalization via Suzuki and Sonogashira couplings. [ABSTRACT FROM AUTHOR]

The Ugi adducts prepared from propiolic acids, propargylamines, indole-2-carbaldehydes, and isocyanides were utilized to assemble polycyclic indole-fused frameworks via two consecutive carbocyclizations involving triple bonds. First, the peptidyl position of Ugi adduct underwent potassium carbonate-mediated cyclization onto the triple bond derived from propiolic acid. Then, the position 3 of indole core engaged into gold-catalyzed cyclization onto the propargylamine-originated alkyne, completing the construction of polycyclic core. [ABSTRACT FROM AUTHOR]

A series of N,O-chelated azine-enol boron complexes featuring four different fusion patterns between the benzene and pyridine rings of the azine fragment was synthesized and characterized. The optical properties of the corresponding complexes have been assessed in dichloromethane solution and in solid state. In the latter case the assessment was performed for both powder samples as well as batches of single crystals allowing to identify several cases of mechanochromism and one case of polymorphism-dependent emission. The correlations between the type of crystal packing and the emission strength of the crystalline samples have been pointed out. [Display omitted] • Ring fusion pattern affects properties of N,O-chelated azine-enol boron complexes. • Their emission in dilute solutions can arise either from π−π* or from ICT transition. • Crystal packing has a significant impact on solid-state fluorescence. • Two polymorphs of the same dye may display different photophysical properties. [ABSTRACT FROM AUTHOR]

A concise assembly of the 1,3-benzodiazepine core from A 3 -coupling-derived propargylamines and ortho -bromophenylisocyanates is described. The developed synthetic sequence involves the addition of propargylamine to isocyanate followed by palladium-catalyzed intramolecular alkyne hydroarylation that could be accomplished in a stepwise or one-pot manner. [ABSTRACT FROM AUTHOR]

Structure–activity relationship studies of a 1,2,4-triazolo-[3,4- b ]thiadiazine scaffold, identified in an HTS campaign for selective STAT3 pathway inhibitors, determined that a pyrazole group and specific aryl substitution on the thiadiazine were necessary for activity. Improvements in potency and metabolic stability were accomplished by the introduction of an α-methyl group on the thiadiazine. Optimized compounds exhibited anti-proliferative activity, reduction of phosphorylated STAT3 levels and effects on STAT3 target genes. These compounds represent a starting point for further drug discovery efforts targeting the STAT3 pathway. [ABSTRACT FROM AUTHOR]

A copper(II) triflate-catalyzed diethylamine-assisted protocol for the reaction of 2-aminonicotinaldehydes and terminal alkynes leading to 1,8-naphthyridines is described. The overall process presumably involves a copper(II) triflate-catalyzed hydroamination of the triple bond followed by the Friedländer-type condensation of the resulting enamine with 2-aminonicotinaldehyde. [ABSTRACT FROM AUTHOR]

A catalyst-free protocol for the reaction of 2-methylazines and aryl glyoxal hydrates leading to α-hydroxy ketones bearing azaarene moiety is described. The process is operationally simple and can be applied to a broad range of substrates. [ABSTRACT FROM AUTHOR]

A two-step one-pot sequence, involving Ugi reaction followed by base-promoted carbocyclization accompanied by cleavage of the isocyanide-originated amide moiety, has been successfully elaborated in order to provide a fast access to 6,7-dihydro-5 H -pyrrolo[3,4- b ]pyridin-5-ones. When the cyclizations were run under air atmosphere a subsequent oxidation occurred producing oxidized 7-hydroxy-6,7-dihydro-5 H -pyrrolo[3,4- b ]pyridin-5-ones. [ABSTRACT FROM AUTHOR]