Palladium nanoparticles on DNA have been shown to be an effective and reusable heterogeneous catalyst for the copper- and ligand-free Sonogashira coupling reaction of aryl iodides under mild conditions in air.

A new synthetic strategy to obtain new linked 1,5-disubstituted tetrazole-1,2,3-triazoles via the Ugi-azide reaction followed by a copper-catalyzed alkyne-azide reaction (CuAAC) was developed. This strategy used solvent-free conditions for the Ugi-azide reaction. This two-step strategy affords the products in moderate to good yields. To the best of our knowledge, this is the first report using the CuAAC reaction as a post-condensation process in an Ugi-azide reaction and therefore, the first describing the synthesis of 1,5-disubstituted tetrazole (1,5-DS-T) linked to the 1,2,3-triazole moiety, which are molecules that may have potential applications in medicinal chemistry.

The first gold(I)-catalyzed cycloisomerization procedure applied to the synthesis of substituted 4H-benzo[d][1,3]oxazines has been developed starting from N-(2-alkynyl)aryl benzamides. The chemoselective oxygen cyclization via the 6-exo-dig pathway yielded the observed heterocycles in modest to good chemical yields under very mild reaction conditions. The obtained oxazines were assayed on the breast cancer (BC)-derived cell lines MCF-7 and HCC1954 with differential biological activity. The newly synthesized 4H-benzo[d][1,3]oxazine compounds showed several degrees of cell proliferation inhibition with a remarkable effect for those compounds having a substituted aryl at C-2 of the molecules. The 4H-benzo[d][1,3]oxazines showed an IC₅₀ ranking from 3.1 to 95 μM in MCF-7 and HCC1954 cells. These compounds represent potential drug candidates for BC treatment. However, additional assays are needed to elucidate their complete effect over the cellular and molecular hallmarks of cancer.

In regard to the actual public health global emergency and, based on the state of the art about the ways to inhibit the SARS-CoV-2 treating the COVID19, a family of 1,5-disubstituted tetrazole-1,2,3-triazoles, previously synthesized, have been evaluated through in silico assays against the main protease of the mentioned virus (CoV-2-M^Pro). The results show that three of these compounds present a more favorable interaction with the selected target than the co-crystallized molecule, which is a peptide-like derivative. It was also found that also hydrophobic interactions play a key role in the ligand-target molecular couplings, due to the higher hydrophobic surfaces into the active site. Finally, a pharmacophore model has been proposed based on the results below, and a family of 1,5-DT derivatives has been designed and tested with the same methods employed in this work. It was concluded that the compound with the isatin as a substituent (P8) present the higher ligand-target interaction, which makes this a strong drug candidate against COVID19, due can inhibit the CoV-2-M^Proprotein.

A high-order multicomponent reaction involving a six-component reaction to obtain the novel linked 1,5-disubstituted tetrazole-1,2,3-triazole hybrids in low to moderate yield is described. This one-pot reaction is carried out under a cascade process consisting of three sequential reactions: Ugi-azide, bimolecular nucleophilic substitution (S_N2), and copper-catalyzed alkyne–azide reaction (CuAAC), with high atom and step-economy due the formation of six new bonds (one C-C, four C-N, and one N-N). Thus, the protocol developed offers operational simplicity, mild reaction conditions, and structural diversity. Finally, to evaluate the antitumoral potential of the synthetized molecules, a proliferation study was performed in the breast cancer (BC) derived cell line MCF-7. The hybrid compounds showed several degrees of cell proliferation inhibition with a remarkable effect in those compounds with cyclohexane and halogens in their structures. These compounds represent potential drug candidates for breast cancer treatment. However, additionally assays are needed to elucidate their complete effect over the cellular hallmarks of cancer.