Equipe PSO

Publications Internationales / Equipe PSO

Specklin S, Gallier F, RofiaMezaache, Harkat H, Dembelé YA, Weibel J-M, Blanc A, Pale P. Copper(II) bromide as efficient catalyst for silyl- to bisarylmethyl ethers interconversion (transprotection). Tetrahedron Letters [Internet]. 2011;52 (44) :5820-5823. Publisher's VersionAbstract

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

 

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

 

RofiaMezaache, Harkat H, Obszynski J, Benkouider A, Blanc A, Weibel J-M, Pale P. Copper(II) bromide as an efficient catalyst for acetal to bisarylmethyl ether interconversion. Tetrahedron Letters [Internet]. 2014;55 (52) :7167-7171. Publisher's VersionAbstract

Transprotection of acetals to bis(methoxyphenyl)methyl (BMPM) ethers can be efficiently achieved in the presence of copper dibromide as catalyst in acetonitrile at room temperature. Acetals are conveniently and selectively converted to the corresponding mono-protected diol with bis(methoxyphenyl)methyl isopropyl ether (BMPMOiPr) as the reagent. This new practical reagent allows the BMPM transfer to 1,3-dioxolanes or 1,3-dioxanes under copper catalysis. The reaction conditions are also very mild and tolerant to various functional groups, including other protecting groups.

Specklin S, Gallier F, Mezaache R, Harkat H, Yénimégué A, Weibel J-M, Blanc A, Pale P. Copper(II) Bromide as Efficient Catalyst for Silyl- to Bisarylmethyl Ethers Interconversion (Transprotection). Tetrahedron Letters [Internet]. 2011;52 (44) :5820-5823. Publisher's VersionAbstract

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Harkat H, Borghèse S, Nigris M, Kiselev S, Bénéteau V, Pale P. ChemInform Abstract: Zeo-Click Synthesis: Copper-Zeolite-Catalyzed Synthesis of Ynamides. Advanced Synthesis & Catalysis [Internet]. 2014;356 (18) :3842-3848. Publisher's VersionAbstract

Copper(I)-zeolites, especially copper(I)-ultra stable Y zeolite (USY), are very efficient heterogeneous catalysts for the coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. Under these conditions, sulfonylated alkyl- or arylamines and various N-heterocycles, such as oxazolidinones or indoles, could be efficiently transformed into the corresponding N-alkynyl derivatives. However, imidazoles gave addition products rather than coupling products. The reaction conditions proved compatible with a variety of functional and protecting groups. Such zeolitic catalysts can be recycled and reused at least five times without significant deactivation. Low catalyst loading could be used (4 mol%) and as low as 0.8 mol% of this heterogeneous copper catalyst still gave good conversion and yields.

 

 

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Ouache R, Harkat H, Pale P, Oulmi K. Phytochemical compounds and anti-corrosion activity of Veronica rosea. Natural Product Research [Internet]. 2019;33 :1-5. Publisher's VersionAbstract

The aim of this work is the phytochemical study of the butanolic extract of the aerial parts of Veronica rosea. Four compounds 14 have been isolated using different chromatographic methods. The structures of these compounds were determined by NMR spectral analysis and mass spectroscopy. The adsorption and anticorrosion effects of this extract were investigated towards the corrosion of copper in 1 M HNO3 aqueous by the weight loss technique and potentiodynamic polarization. The results showed that the butanolic extract is a good inhibitor and the inhibition efficiency increases with increasing of concentration of the inhibitor. The adsorption of this extract on the copper specimen surface was spontaneous and obeyed the Langmuir’s adsorption isotherm. Large value of adsorption equilibrium Constant (K ads = 35 L g−1) was obtained. The polarization experiments confirmed the data obtained by gravimetric weight-loss. Tafel plot of polarization curves indicates that the extract acts as a mixed type inhibitor.

Graphical abstract

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