Rocío Gámez-Montaño

Three‐Component Metal‐Free Arylation of Isocyanides

Though the efficiency of isocyanides as strong ligands for transition metals was recognized very early, the disclosure of metal-catalyzed arylation of isocyanides has only been explored quite recently. In most of these studies, the formation of a metal/aryl complex starting from aryl iodide or bromide is followed by isocyanide insertion and trapping of the metal/imidoyl complex with various nucleophiles (Scheme 1). These three-component couplings are mostly

New palladium-catalyzed aerobic oxidative cleavage and cyclization of N-aryl peptide derivatives.

Oxidative cleavage and cyclization cascades of N-aryl peptides have been achieved under palladium catalysis with air as the sole stoichiometric oxidant.

Synthesis of 3-tetrazolylmethyl-4H-chromen-4-ones via Ugi-azide and biological evaluation against Entamoeba histolytica, Giardia lamblia and Trichomona vaginalis

The synthesis of novel 3-tetrazolylmethyl-4H-chromen-4-ones via an Ugi-azide multicomponent reaction and their biological evaluation against Entamoeba histolytica, Giardia lamblia and Trichomona vaginalis are described. Reported yields are moderate to good and biological results show that these compounds could be considered as candidates to anti-parasitic drugs, especially against G. lamblia.

Microwave-assisted C-3 selective oxidative radical alkylation of flavones

Flavones were directly alkylated at the C-3 position in moderate yields using a xanthate-based oxidative radical addition procedure. This methodology is a suitable synthetic tool for the direct substitution of the vinylic and unactivated C-H bond of the C ring of the flavone by an alkyl functionality under neutral conditions.

Synthesis of azepino[4,5-b]indol-4-ones via MCR/free radical cyclization and in vitro–in silico studies as 5-Ht6R ligands

A series of nine new 3-acetamide-azepino[4,5-b]indol-4-ones were synthesized in two steps: (i) multicomponent reaction (Ugi-4CR/SN2) and (ii) free radical-mediated cyclization. These compounds, along with their tetrazole-based analogs, were studied in vitro to assess their binding with the 5-hydroxytryptamine type 6 receptor (5-Ht6R). The 3-acetamide-azepino[4,5-b]indol-4-ones displayed moderate affinity, whereas the 3-tetrazolylmethyl-azepino[4,5-b]indol-4-ones affinity values are lower. However, one of the 3-acetamide-azepino[4,5-b]indol-4-ones exhibited a hit value of Ki (211.2nM) to the 5-Ht6R. Minimal-energy structures of one cis-amide and its tetrazole-based analog (calculated by means of the Density Functional Theory) were analyzed to assess some interesting bioisosterism aspects. Interactions and binding energies between all products and the 5-Ht6R were calculated through in silico molecular couplings. Finally, a QSAR model was proposed using the results of the in vitro assays.

Insertion of Isocyanides into N−Si Bonds: Multicomponent Reactions with Azines Leading to Potent Antiparasitic Compounds

Trimethylsilyl chloride is an efficient activating agent for azines in isocyanide-based reactions, which then proceed through a key insertion of the isocyanide into a N-Si bond. The reaction is initiated by Nu2005activation of the azine, followed by nucleophilic attack of an isocyanide in a Reissert-type process. Finally, a second equivalent of the same or a different isocyanide inserts into the N-Si bond leading to the final adduct. The use of distinct nucleophiles leads to a variety of α-substituted dihydroazines after a selective cascade process. Based on computational studies, a mechanistic hypothesis for the course of these reactions was proposed. The resulting products exhibit significant activity against Trypanosomau2005brucei and T.u2005cruzi, featuring favorable drug-like properties and safety profiles.

Endogenous water-triggered and ultrasound accelerated synthesis of 1,5-disubstituted tetrazoles via a solvent and catalyst-free Ugi-azide reaction

A novel, sustainable, endogenous water-triggered, environmentally friendly, high substrate scope, efficient, solvent-free and catalyst-free Ugi-azide based method for the synthesis of 1,5-disubstituted tetrazoles is described.

In Vitro Studies of Chromone-Tetrazoles against Pathogenic Protozoa, Bacteria, and Fungi

In vitro studies to fourteen previously synthesized chromone-tetrazoles and four novel fluorine-containing analogs were conducted against pathogenic protozoan (Entamoeba histolytica), pathogenic bacteria (Pseudomonas aeruginosa, and Staphylococcus aureus), and human fungal pathogens (Sporothrix schenckii, Candida albicans, and Candida tropicalis), which have become in a serious health problem, mainly in tropical countries.

Synthesis of 1,5-disubstituted tetrazoles containing a fragment of the anticancer drug imatinib via a microwave-assisted Ugi-azide reaction

Thirty novel N1-[(1-alkyl-1H-tetrazol-5-yl)(aryl)methyl]-4-methyl-N3-[4-(pyridine-3-yl)pyrimidin-2-yl]benzene-1,3-diamines were synthesized in moderate to good yields (50–85xa0%) via a microwave-assisted Ugi-azide reaction. These products may exhibit cytotoxicity and/or tyrosine-kinase inhibitory properties because of their structural similarities with potent anticancer drugs such as imatinib. Finally, in order to visualize the stereoelectronic nature of Schiff bases having various basic sites involved in the Ugi-azide reaction mechanism, we analyzed a molecular electrostatic potential surface, which was plotted by means of density functional theory at the UB3LYP/6-311G(d) level.Graphical abstract

Synthesis of 2-julolidin-imidazo[1,2-a]pyridines via Groebke–Blackburn–Bienaymé reaction and studies of optical properties

A series of sixteen new 2-julolidin-imidazo[1,2-a]pyridine bound-type bis-heterocycles were synthesized in good to excellent yields (61–98%) via an MW-assisted Groebke–Blackburn–Bienayme (GBB) reaction. Then, experimental studies were conducted to determine the luminescence properties of these compounds. Various high quantum yields were found. In fact, one product exhibited a quantum yield (86.6%) comparable to that of the reference compound rhodamine (94.8%). Finally, further computational studies were performed by means of TD-DFT to calculate their HOMO–LUMO distributions and theoretical absorption spectra. A good agreement between the experimental and computational results was obtained, which provides a rationalized explanation for the observed structure/property relationships.