Halogen-containing heteroaromatic carbenes of the 1,2,4-triazole series and their transformations

Abstract

A series of new stable halogenated carbenes, 1-tert-butyl-3,4-diaryl-1,2,4-triazol-5-ylidenes, has been synthesized.

Synthesis and Antimicrobial Activity of Carbene Complexesof the Imidazole, Benzimidazole and 1,2,4‐Triazole Series

“…However, derivatives of 4-monofluoroaryl substituted 1,2,4triazol-5-ylidenes (T 1 -T 3 ) have positive values (5.7-11.0 kcal/ mol) and should be stable that has already been confirmed experimentally. [16] For o-CF 3 and p-CF 3 -substituted compounds T 4 , T 5 the studies were performed for three possible isomers of dimers cis-cis-trans (cct), trans-trans-trans (ttt) and trans-trans-cis (ttc). The first configuration refers to substituents at nitrogen atoms of one cycle of the dimer, the second is the same for another cycle, and the third reflects the relative position of triazole cycles in dimers.…”

“…Among them, derivatives of fluorine-containing, carbene-heterocyclic derivatives (e. g., PEP-PSI-complexes), copper carbene complexes and complexes with long-chain aliphatic substituents have not been studied enough. [16] Many known organofluorine compounds are biologically active, including drugs and preparations for agriculture (for reviews, see, for example [17][18][19][20] ). The antibacterial activity of fluorine-substituted carbene derivatives, imidazol-2-ylidene gold complexes A-D (Scheme 1), show significant action on human tumor cell lines [ 21,22 and references therein].…”

“…Carbenoid compounds (organic salts and carbene complexes of transition metals) are well known for their biological activities, [1–5] including antitumor, antimicrobial (antibacterial, antifungal), [6–10] antimalarial, [11] antileishmanial, [12] antinematodic [13] actions, properties of inhibitors of mosquitoes, [14] enzymes, [15] etc. Among them, derivatives of fluorine‐containing, carbene‐heterocyclic derivatives (e. g., PEPPSI‐complexes), copper carbene complexes and complexes with long‐chain aliphatic substituents have not been studied enough [16] …”

Synthesis and the Antimicrobial Activity of Salt Carbenoid Compounds

“…Fluorine-containing zwitterion 10 (94 % yield) and for comparison the known compound 11 (81 % yield) were both synthesized by in situ conversion of the corresponding salts in the reaction with phenylisothiocyanate in the presence of potassium carbonate in acetonitrile at room temperature. Previously, compound 11 was also obtained by the reaction of the corresponding carbene with phenylisothiocyanate [16]. It should be noted that obtaining carbene from salt 1c is impossible due to its easy dimerization.…”

“…The study was carried out by two methods [17,18]: 1) the agar diffusion method to determine diameters of the growth inhibition zones of microorganisms (Method A), and 2) the serial dilutions method to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal (MBC) and fungicidal (MFC) concentrations (Method B) (see Experimental part). The activities of the compounds synthesized were compared to the activity of a known broadly used antimicrobial drug 1-cetylpyridinium chloride 12, which characteristics are given under the same conditions in the article [16], and with the activity of selected compounds 13, 14 synthesized in the work [8].…”