Rodrigo González-Olvera

Versatile O- and S-functionalized 1,2,3-triazoliums: ionic liquids for the Baylis–Hillman reaction and ligand precursors for stable MIC-transition metal complexes

The efficient synthesis of O- and S-functionalized 1,2,3-triazoliums is reported. Owing to their physical properties, these cations are efficient ionic liquids for Baylis–Hillman addition under mild reaction conditions. Simultaneously, the functionalization of the triazolium rings allows for the in situ C-5 metallation providing air stable triazol-5-ylidene Rh(I) Au(I), and Pd(II) complexes. The present work constitutes a rare example of versatile triazolium salts capable of serving in two unrelated synthetic procedures.

Multicomponent Click Synthesis of New 1,2,3-Triazole Derivatives of Pyrimidine Nucleobases: Promising Acidic Corrosion Inhibitors for Steel

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.

Synthesis of New 1,2,3-Triazole Derivatives of Uracil and Thymine with Potential Inhibitory Activity against Acidic Corrosion of Steels

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.

Multicomponent Synthesis and Evaluation of New 1,2,3-Triazole Derivatives of Dihydropyrimidinones as Acidic Corrosion Inhibitors for Steel.

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.

Cu–Al mixed oxide catalysts for azide–alkyne 1,3-cycloaddition in ethanol–water

Cu(Al)O mixed oxides, which are obtained by the calcination of Cu–Al layered double hydroxide (LDH), promote the formation of 1,2,3-triazoles from an alkyne–azide cycloaddition reaction (Huisgen-type reaction) with excellent yields using an EtOH–H2O mixture as the solvent under microwave heating. The yield of the reaction is the result of both heterogeneous and homogeneous catalytic processes, as a consequence of capturing Cu(II) from the material by sodium ascorbate. Although the appropriate reaction conditions were employed (EtOH–H2O, 80 °C, MW, 10 min), the reconstruction of LDH by the so-called memory effect was not observed.

Electrochemical assessment of phenol and triazoles derived from phenol (BPT) on API 5L X52 steel immersed in 1 M HCl

The corrosion inhibition of phenol triazoles was tested with several halogens by means of electrochemical impedance and potentiodynamic polarization. We observed the importance of the 1,2,3-triazole ring in the chemical structure because significant inhibition efficiencies (η) > 90% were achieved at low concentrations with the different halogens. These compounds have a physisorption-type adsorption process, in accordance with the Langmuir model. For long immersion times, the organic inhibitor BPTI showed good corrosion protection during 504 hours of immersion with η > 80%. Furthermore, the hydrodynamic conditions proved that organic molecules experience a desorption process related to the different rotation velocities employed. Finally, it was demonstrated by SEM that the corrosion velocity is diminished when using the BPTI inhibitor at 50 ppm.

Synthesis of β-nitrostyrenes in the presence of sulfated zirconia and secondary amines

A simple and efficient protocol for the synthesis of β-nitrostyrenes has been achieved by the use of sulfated zirconia–secondary amine (piperidine, pyrrolidine, proline or prolinol) cooperative systems. The condensation of different aldehydes and nitromethane demonstrates the efficiency of this process, which does not require high-temperature reactivation for the reuse of the catalytic material.