Cu(I)-Catalyzed Regioselective Synthesis of Pyrazolo[5,1-<i>c</i>]-1,2,4-triazoles

Cycloadditions of terminal alkynes to 1,2,4-triazolium <i>N</i>-imides in the presence of base and Cu­(I) afford pyrazolo­[5,1-<i>c</i>]-1,2,4-triazoles regioselectively. The scope of alkynes, the influence of the electronic nature of the leaving group, and variations in the 1-alkyl substituent were examined. Quantum chemical calculations were employed to explain the distinct reactivity of the propiolates

Push-Pull Triazenes Derived from 1‑(Benzylideneamino)- and 1‑(Sulfonimido)-azolylidenes

In-situ-generated neutral 1-(benzylideneamino)- and novel anionic 1-(sulfonimido)-azolylidenes react with organic azides to afford diverse classes of push-pull triazenes and triazene salts. The scope of the heterocyclic core and substituents at the N1 and N3 positions of NHC precursors together with the thermal properties of resulting compounds were examined

Synthesis and Direct C2 Functionalization of Imidazolium and 1,2,4‑Triazolium <i>N</i>‑Imides

Pd-catalyzed direct C2 arylation and Cu-catalyzed direct one-pot alkynylation/intramolecular cyclization of azolium <i>N</i>-imides are reported. Various acetylenes, aryl iodides, and 1-alkyl substituents were examined. The mild protocol allows direct C2 arylation of azolium <i>N</i>-imides without the use of specialized reagents together with novel one-pot regioselective preparations of imidazole-pyrazolo and pyrazolo-1,2,4-triazole ring systems. The electronic properties of selected examples were examined by fluorescence spectroscopy

Synthesis, Bioassay, and Molecular Field Topology Analysis of Diverse Vasodilatory Heterocycles

A diverse training set composed of 76 in-house synthesized and 61 collected from the literature was subjected to molecular field topology analysis. This resulted in a high-quality quantitative structure–activity relationships model (<i>R</i>² = 0.932, <i>Q</i>² = 0.809) which was used for the topological functional core identification and prediction of vasodilatory activity of 19 novel pyridinecarbonitriles, which turned out to be active in experimental bioassay