Deux exemples de "chimie éco-responsable"

International audienceÀ partir de la règlementation REACH et des principes de la chimie verte, deux exemples de synthèse organique, l'une utilisant des dérivés du silicium en particulier le PHMS et le TMDS et l'autre la synthèse économe d'éthers de glycérol, illustrent la démarche "éco-compatible" des nouveaux procédés

Amidation of phenol derivatives : a direct synthesis of paracetamol (acetaminophen) from hydroquinone.

International audienceA direct synthesis of paracetamol (acetaminophen) from hydroquinone has been developed using ammonium acetate as an amidating agent. The reaction proceeds in acetic acid at elevated temperatures without any metallic catalyst. Under these conditions, paracetamol was obtained with high yield and selectivity (>95%). The reaction has also been carried out on the multi-gram scale (44 g of hydroquinone) and a potential process has been proposed based on the recycling of the solvent and by-products. This amidation protocol has also been extended to other phenol derivatives

Novel access to N,N'-diaryl-trans-1,2-diaminocyclohexane ligands. A cheap and easy way to prepare ligand for asymmetric transfer hydrogenation

International audienceN,N′-diaryl-trans-1,2-diaminocyclohexane ligands were prepared from 1,2-diaminocyclohexane and cyclohexanone derivatives via a heterogeneous palladium catalysis. In one step an alkylation followed by an aromatisation is performed under air or in the presence of an hydrogen trap. The interest of the synthesized ligands were evaluated in the reduction of aromatic ketones. The alcohols were efficiently and selectively obtained with an iridium complex and a mixture of formic acid and sodium formate