Efficient one-pot synthesis of amino-benzotriazolodiazocinone scaffolds via catalyst-free tandem Ugi-Huisgen reactions

3-Substituted 2-isocyanopyridines as versatile convertible isocyanides for peptidomimetic design

We report the use of 3-substituted 2-isocyanopyridines as convertible isocyanides in Ugi four-component reactions. The N-(3-substituted pyridin-2-yl)amide Ugi products can be cleaved by amines, alcohols, and water with Zn(OAc)2 as a catalyst. In addition, the applicability of the method was demonstrated in constrained di-/tripeptides bearing acid and base sensitive protective groups obtained via Ugi-4CR post-condensation modifications.

Post-Ugi Cyclization for the Construction of Diverse Heterocyclic Compounds: Recent Updates

Multicomponent reactions (MCRs) have proved as a valuable tool for organic and medicinal chemist because of their ability to introduce a large degree of chemical diversity in the product in a single step and with high atom economy. One of the dominant MCRs is the Ugi reaction, which involves the condensation of an aldehyde (or ketone), an amine, an isonitrile, and a carboxylic acid to afford an α-acylamino carboxamide adduct. The desired Ugi-adducts may be constructed by careful selection of the building blocks, opening the door for desired post-Ugi modifications. In recent times, the post-Ugi transformation has proved an important synthetic protocol to provide a variety of heterocyclic compounds with diverse biological properties. In this review, we have discussed the significant advancements reported in the recent literature with the emphasis to highlight the concepts and synthetic applications of the derived products along with critical mechanistic aspects.

Rapid construction of substituted 3-amino-1,5-benzothiazepin-4(5H)-one dipeptide scaffolds through an Ugi-4CR - Ullmann cross-coupling sequence

A 3-step methodology for the synthesis of 1,5-benzothiazepin-4(5H)-one dipeptidomimetics has been elaborated via an Ugi-4CR followed by a S-trityl deprotection and an intramolecular Cu(i)-catalyzed Ullmann condensation with moderate to good yields. In silico and NMR conformational studies showed that the lowest energy conformers stabilize γ- and β-turn structures.

Synthesis, DNA binding affinity and anticancer activity of novel 4H-benzo[g][1,2,3]triazolo[5,1-c][1,4]oxazocines

A new class of tricyclic heterocycles 4H-benzo[g][1,2,3]triazolo[5,1-c][1,4]oxazocines was synthesized through a Knoevenagel condensation/azide-alkyne cycloaddition reaction cascade in one-pot operation. These eight membered ring containing heterocycles exhibited moderately high anticancer activity against four cancer cell lines; human cervix cancer cell line (HeLa), human prostate cancer cell line (DU145), human breast cancer cell line (MCF-7) and human breast adenocarcinoma epithelial cell line (MDA-MB-231). Our results indicate that these compounds have a weak cytotoxic effect on normal human mammary epithelial cell line (MCF-10A). Cell cycle and apoptosis assay indicate that they inhibit the cell cycle at the G2/M phase and induce apoptosis. Through the RED₁₀₀ assay, it is evident that they have potential to inhibit pBR 322 plasmid DNA cleavage by BamH1. UV-visible, fluorescence titration and viscosity studies suggested that these compounds possess DNA binding affinity.