Hansen and COSMO-RS approaches show that glycerol ketals and acetals can be effective alternatives to certain harmful petro-sourced solvents.

A new family of cationic organometallic chloro compounds of the type [(arene)Ru(N,N)(Cl)] þ containing N, N-chelating dipyridylamine ligands has been synthesized and isolated as the chloride salts, which are water soluble and stable to hydrolysis. The resulting mononuclear ruthenium complexes catalyze the transfer hydrogenation of aryl ketones in aqueous solution to give the corresponding alcohols with good conversion and interesting recyclability.

A copper(i) catalyzed amination reaction utilizing aqueous ammonia and operating under mild conditions is presented. This method was employed for the efficient synthesis of various aminopyridine derivatives bearing electron withdrawing and electron donating groups.

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Sterically hindered, symmetrically 2,2 0 -substituted bispyridylamines 1a-c and methylenebispyridine 4 were prepared in a three-step procedure from commercially available 2,6-dibromopyridine, via a Cu-mediated alkylation followed by two consecutive Buchwald-Hartwig N-arylation reactions or two Negishi cross-coupling reactions, respectively, in the presence of Pd catalysts. Deprotonation of the NH and CH 2 bridge of 1a and 4, respectively, enables the formation of Zn(II) and Mg(II) complexes, whose structures have been determined by singlecrystal diffraction studies and/or NMR spectroscopy. A magnesium-isopropyl complex stabilized by a bispyridyldiiminate ligand derived from 4 is shown to be an active catalyst for the isotactic polymerization of methyl methacrylate.

-An efficient protocol for the self-metathesis of oleic acid, using ruthenium catalysts is described. The self-metathesis reaction under ultrasonic activation allows the conversion of monoenic fatty acids such as oleic acid, elaidic acid and erucic acid into diacids and olefins with very short reaction times in the presence of Grubbs ruthenium catalysts. These yields and selectivity towards the desired products are influenced by the nature of solvents. This study demonstrated that metathesis reaction carried out in DCM or 1-butanol showed promising results, since it produced a variety of products, like n-alkenes and diacids with good yields (45-75%) and high selectivities (75-95%).Keywords: Self-metathesis / long-chain diacids / oleic acid / 1,18-octadec-9-enedioic acid / 1,26-hexacos-13-enedioic acid Résumé -Métathèse activée par les ultrasons : homocouplage d'acides gras monoinsaturés. Un nouveau protocole efficace pour l'homocouplage de l'acide oléique par réaction métathèse utilisant des catalyseurs de ruthénium est décrit dans cet article. La réaction d'homocouplage activée par ultrasons permet d'obtenir avec des temps de réac-tion très faibles, la conversion d'acides gras insaturés tels que l'acide oléique, l'acide élaïdique et l'acide érucique en diacides et oléfines en présence de catalyseurs au ruthénium de Grubbs. Les rendements et la sélectivité des produits obtenus sont influencés par la nature du solvant utilisé. Cette étude a démontré que la réaction de métathèse réalisée dans du dichlorométhane ou du 1-butanol donne des résultats prometteurs : elle permet d'obtenir une grande variété d'alcènes et des diacides à longues chaînes avec de bons rendements (45-75 %) et des sélectivités élevées (75-95 %). Mots clés :Homocouplage / métathèse / diacides à longue chaîne / acide oléique / acide 1,18-octadéc-9-ènedioïque / acide 1,26-hexacos-13-ènedioïque

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Derivatives via Copper and Palladium Catalysis. -Pd-catalyzed amination of 2-bromopyridines with 2-aminopyridines offers a simple synthesis of bispyridylamines. -(GAILLARD, S.; ELMKADDEM, M. K.; FISCHMEISTER, C.; THOMAS, C. M.; RENAUD, J.-L.; Tetrahedron Lett. 49 (2008) 21, 3471-3474; Sci. Chim., CNRS, Ec. Natl. Super. Chim., F-35700 Rennes, Fr.; Eng.) -Mais 35-140