The preparation and full characterization of a variety of mono-([L1-H]), di-([L2-H 2 ], [L2A-H2]), and tri-([L3-H 3 ]) 1,2,3-triazolium salts constructed form "clicked" hydroxybenzene derivatives are reported. Deprotonation with potassium hexamethyldisilazide, followed by in situ metalation, allowed for the synthesis of a series of mono-(L1•[M]), di-(L2•[M] 2 , L2•[M] 2 ), and trinuclear (L3•[M] 3 ) group 9−11 (M = [Rh(CO) 2 Cl], [Pd(allyl)Cl], and [AuCl]) triazol-5-ylidene metal complexes. In solution, all metal complexes feature symmetrical patterns displaying C 2 and C 3 fold axes when supported by di-and tritriazol-5-ylidene ligands. The vibration frequencies of Ln•[Rh(CO) 2 Cl] n (n = 1−3) complexes indicate that the electron-donor properties of the new ligands are comparable to those for previously reported MIC complexes and superior to classical NHCs. Prompting coordination of the vicinal phenoxy group to the metal centers proved unsuccessful after treatment of the Ln•[Rh(CO) 2 Cl] n and Ln•[Pd(allyl)Cl] n (n = 1−3) precursors with AgBF 4 ; the expected chelated cationic complexes were highly unstable, indicating a weak or no coordination availability through the oxygen atom. Crystal structures of the complexes L1•[AuI] and L2A•[Pd(allyl)I] 2 illustrated the metal center geometrical environment and confirmed the lack of coordination through the phenoxy moiety of the ligand. Preliminary catalytic trials established the enhanced performance of di-and trimetallic palladium complexes in cross-coupling reactions and the intramolecular cyclization of enynes catalyzed by gold complexes.

A series of new mono-1,2,3-triazole derivatives of pyrimidine nucleobases were synthesized by one-pot copper(I)-catalyzed 1,3-dipolar cycloaddition reactions between N-1-propargyluracil and thymine, sodium azide and several benzyl halides. The desired heterocyclic compounds were obtained in good yields and characterized by NMR, IR, and high resolution mass spectrometry. These compounds were investigated as corrosion inhibitors for steel in 1 M HCl solution, using electrochemical impedance spectroscopy (EIS) technique. The results indicate that these heterocyclic compounds are promising acidic corrosion inhibitors for steel.

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Ten 1,4-disubstituted 1,2,3-triazoles were synthesized from one of 1-(azido-methyl)benzene, 1-(azidomethyl)-4-fluorobenzene, 1-(azidomethyl)-4-chlorobenzene, 1-(azidomethyl)-4-bromobenzene or 1-(azidomethyl)-4-iodobenzene, generated in situ from sodium azide and the corresponding benzyl halide, and dipropargyl uracil or dipropargyl thymine. Optimal experimental conditions were established for the conventional click chemistry. The corrosion inhibiting properties of some of these compounds, which were determined by means of an electrochemical technique, are also presented.

An efficient one-pot synthesis of 1,2,3-triazole derivatives of dihydropyrimidinones has been developed using two multicomponent reactions. The aldehyde-1,2,3-triazoles were obtained in good yields from in situ-generated organic azides and O-propargylbenzaldehyde. The target heterocycles were synthesized through the Biginelli reaction in which the aldehyde-1,2,3-triazoles reacted with ethyl acetoacetate and urea in the presence of Ce(OTf) 3 as the catalyst. The corrosion inhibition of steel grade API 5 L X52 in 1 M HCl by the synthesized compounds was investigated using the electrochemical impedance spectroscopy technique. The measurements revealed that these heterocycles are promising candidates to inhibit acidic corrosion of steel.