Taoufik Rohand | University Mohamed Premier (Sciences) (original) (raw)
Papers by Taoufik Rohand
Tetrahedron Letters, Jul 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
![Research paper thumbnail of Synthesis, Characterization, and Antimicrobial Activity of a Novel Trisazo Dye from 3-Amino-4H-thieno[3,4-c][1]benzopyran-4-one](https://attachments.academia-assets.com/112019017/thumbnails/1.jpg)
](International journal of medicinal chemistry, Feb 1, 2018
A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][... more A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][1]benzopyran-4-one with 2tert-butyl-4-methoxyphenol. The newly prepared trisazo dye was characterized by its physical, elemental, and spectroscopic data. 2D-NMR (COSY, HSQC, and HMBC) techniques were used to secure the structural assignments. The new trisazo dye (compound 7) along with precursors 3, 4, and 6 was screened by microdilution susceptibility assay for antibacterial and antifungal activities towards eight bacterial strains and three yeasts selected on the basis of their relevance as human pathogens. The results showed that compound 7 (MIC = 2-128 g/mL) was the most active as compared with its precursors. The most resistant microorganisms were V. cholerae NB2 and V. cholerae SG24, whereas the most sensitive microorganism was C. neoformans. The overall results of this study indicated that compound 7 had the greatest potential value against both yeasts and multidrug-resistant bacteria, so further investigation is warranted.
Photochemical and Photobiological Sciences, Oct 1, 2007
We have prepared two fluorescent dyes derived from 8-(4-tolyl)-4,4-difluoro-4-bora-3a,4a-diaza-si... more We have prepared two fluorescent dyes derived from 8-(4-tolyl)-4,4-difluoro-4-bora-3a,4a-diaza-sindacene with phenoxy and (o-bromo)phenoxy substituents at the 3,5-positions by a novel nucleophilic substitution reaction of the corresponding 3,5-dichloroBODIPY analogue. UV-vis absorption, steady-state and time-resolved fluorimetry have been used to investigate their solvent-dependent photophysical properties. The two BODIPY derivatives show narrow absorption and emission bands and display small Stokes shifts. The substituents at the 3,5-positions (phenoxy in 1 and o-bromophenoxy in 2) have a minor effect on the fluorescence quantum yields (0.16-0.40 for 1, 0.17-0.44 for 2) and lifetimes (1.09-2.51 ns for 1, 1.11-2.78 ns for 2). For both compounds, the fluorescence rate constant equals (1.5 ± 0.1) × 10 8 s −1 .
Current Organocatalysis
Aim: The synthesis of diverse N-substituted pyrroles utilizing rice malt is identified. The react... more Aim: The synthesis of diverse N-substituted pyrroles utilizing rice malt is identified. The reaction of hexane-2,5-dione with various primary amines develops the intriguing pyrrole scaffold in moderate to good yields. Method: The reaction was carried out at room to ambient temperature in an extremely environmentally benign condition, without the need for any additional solvents or catalysts. Result: In the synthesis of N-derivatized pyrroles, several 1°amines, both cyclic and acyclic residue, have been accomplished. Conclusion: To the best of my knowledge, no study has been reported so far based on Paal-Knorr pyrrole synthesis utilizing rice malt as a catalyst and solvent.
Journal of Molecular Structure
Chemistry – A European Journal
In this work, both separate dipyrromethene and copper corrole derivatives and a specifically desi... more In this work, both separate dipyrromethene and copper corrole derivatives and a specifically designed copper corrole-dipyrromethene conjugate were applied for gold electrode modification. The various oligopyrrole materials were used for copper complexation toward the preparation of different types of electroactive self-assembling monolayers (SAMs): (i) a copper dipyrromethene (Cu-DPM) SAM, (ii) a copper corrole (Cu-COR) SAM, and (iii) a copper dipyrromethene-copper corrole conjugate (Cu-DPM-Cu-COR) SAM. The SAMs incorporating the single Cu sites as well as, two Cu sites located in one molecule, one over another, were characterized by cyclic voltammetry, Osteryoung square-wave voltammetry and electrochemical impedance spectroscopy.
Monatshefte für Chemie - Chemical Monthly, 2018
Ethylene glycol condensed with carbonyl compounds in the presence of silica gel or alumina, witho... more Ethylene glycol condensed with carbonyl compounds in the presence of silica gel or alumina, without solvent and under pressure, affords 1,3-dioxolanes. 2-Amino-2-methylpropanol also condensed with carbonyl compounds in the presence of silica gel or an acid-activated clay, without solvent and under pressure, produces oxazolidines. To explain these results, we propose that the glycol and the aminopropanol react with Brønsted (H ?) and Lewis acid sites (Si and Al) located on the surface of the catalysts, leading to the products via various ionic intermediates.
Chemistry Central journal, Jan 21, 2017
A series of recently reported phenolic azo dyes 7a-e were prepared by coupling the thienyl diazon... more A series of recently reported phenolic azo dyes 7a-e were prepared by coupling the thienyl diazonium sulfate of 3-Amino-4H-benzo[f]thieno[3,4-c](2H)chromen-4-one with selected diversely substituted phenolic and naphtholic derivatives. These compounds were evaluated for their antibacterial and antifungal activities. Furthermore their voltammetric behavior was compared at a glassy carbon electrode. The voltammetric behavior of the five recently reported azo dyes has been compared at a glassy carbon electrode. It is shown that the azo dyes 7a-e with a hydroxyl group in the ortho position with respect to the azo bridge give rise to well defined, irreversible peaks for the oxidation and reduction process within a pH range of 2-7. The mechanisms of electrochemical oxidation of compound 7a-c and 7e are proposed. For the hydroxyl-substituted dyes, re-oxidation peaks were obtained in the subsequent scan. The antimicrobial activities of the reported compounds 7a-e along with the entire precur...
Acta Crystallographica Section E Structure Reports Online
ABSTRACT
Journal of Molecular Structure, 2022
Tetrahedron Letters, Jul 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
International journal of medicinal chemistry, Feb 1, 2018
A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][... more A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][1]benzopyran-4-one with 2tert-butyl-4-methoxyphenol. The newly prepared trisazo dye was characterized by its physical, elemental, and spectroscopic data. 2D-NMR (COSY, HSQC, and HMBC) techniques were used to secure the structural assignments. The new trisazo dye (compound 7) along with precursors 3, 4, and 6 was screened by microdilution susceptibility assay for antibacterial and antifungal activities towards eight bacterial strains and three yeasts selected on the basis of their relevance as human pathogens. The results showed that compound 7 (MIC = 2-128 g/mL) was the most active as compared with its precursors. The most resistant microorganisms were V. cholerae NB2 and V. cholerae SG24, whereas the most sensitive microorganism was C. neoformans. The overall results of this study indicated that compound 7 had the greatest potential value against both yeasts and multidrug-resistant bacteria, so further investigation is warranted.
Photochemical and Photobiological Sciences, Oct 1, 2007
We have prepared two fluorescent dyes derived from 8-(4-tolyl)-4,4-difluoro-4-bora-3a,4a-diaza-si... more We have prepared two fluorescent dyes derived from 8-(4-tolyl)-4,4-difluoro-4-bora-3a,4a-diaza-sindacene with phenoxy and (o-bromo)phenoxy substituents at the 3,5-positions by a novel nucleophilic substitution reaction of the corresponding 3,5-dichloroBODIPY analogue. UV-vis absorption, steady-state and time-resolved fluorimetry have been used to investigate their solvent-dependent photophysical properties. The two BODIPY derivatives show narrow absorption and emission bands and display small Stokes shifts. The substituents at the 3,5-positions (phenoxy in 1 and o-bromophenoxy in 2) have a minor effect on the fluorescence quantum yields (0.16-0.40 for 1, 0.17-0.44 for 2) and lifetimes (1.09-2.51 ns for 1, 1.11-2.78 ns for 2). For both compounds, the fluorescence rate constant equals (1.5 ± 0.1) × 10 8 s −1 .
Current Organocatalysis
Aim: The synthesis of diverse N-substituted pyrroles utilizing rice malt is identified. The react... more Aim: The synthesis of diverse N-substituted pyrroles utilizing rice malt is identified. The reaction of hexane-2,5-dione with various primary amines develops the intriguing pyrrole scaffold in moderate to good yields. Method: The reaction was carried out at room to ambient temperature in an extremely environmentally benign condition, without the need for any additional solvents or catalysts. Result: In the synthesis of N-derivatized pyrroles, several 1°amines, both cyclic and acyclic residue, have been accomplished. Conclusion: To the best of my knowledge, no study has been reported so far based on Paal-Knorr pyrrole synthesis utilizing rice malt as a catalyst and solvent.
Journal of Molecular Structure
Chemistry – A European Journal
In this work, both separate dipyrromethene and copper corrole derivatives and a specifically desi... more In this work, both separate dipyrromethene and copper corrole derivatives and a specifically designed copper corrole-dipyrromethene conjugate were applied for gold electrode modification. The various oligopyrrole materials were used for copper complexation toward the preparation of different types of electroactive self-assembling monolayers (SAMs): (i) a copper dipyrromethene (Cu-DPM) SAM, (ii) a copper corrole (Cu-COR) SAM, and (iii) a copper dipyrromethene-copper corrole conjugate (Cu-DPM-Cu-COR) SAM. The SAMs incorporating the single Cu sites as well as, two Cu sites located in one molecule, one over another, were characterized by cyclic voltammetry, Osteryoung square-wave voltammetry and electrochemical impedance spectroscopy.
Monatshefte für Chemie - Chemical Monthly, 2018
Ethylene glycol condensed with carbonyl compounds in the presence of silica gel or alumina, witho... more Ethylene glycol condensed with carbonyl compounds in the presence of silica gel or alumina, without solvent and under pressure, affords 1,3-dioxolanes. 2-Amino-2-methylpropanol also condensed with carbonyl compounds in the presence of silica gel or an acid-activated clay, without solvent and under pressure, produces oxazolidines. To explain these results, we propose that the glycol and the aminopropanol react with Brønsted (H ?) and Lewis acid sites (Si and Al) located on the surface of the catalysts, leading to the products via various ionic intermediates.
Chemistry Central journal, Jan 21, 2017
A series of recently reported phenolic azo dyes 7a-e were prepared by coupling the thienyl diazon... more A series of recently reported phenolic azo dyes 7a-e were prepared by coupling the thienyl diazonium sulfate of 3-Amino-4H-benzo[f]thieno[3,4-c](2H)chromen-4-one with selected diversely substituted phenolic and naphtholic derivatives. These compounds were evaluated for their antibacterial and antifungal activities. Furthermore their voltammetric behavior was compared at a glassy carbon electrode. The voltammetric behavior of the five recently reported azo dyes has been compared at a glassy carbon electrode. It is shown that the azo dyes 7a-e with a hydroxyl group in the ortho position with respect to the azo bridge give rise to well defined, irreversible peaks for the oxidation and reduction process within a pH range of 2-7. The mechanisms of electrochemical oxidation of compound 7a-c and 7e are proposed. For the hydroxyl-substituted dyes, re-oxidation peaks were obtained in the subsequent scan. The antimicrobial activities of the reported compounds 7a-e along with the entire precur...
Acta Crystallographica Section E Structure Reports Online
ABSTRACT
Journal of Molecular Structure, 2022