Mono- and double carbonylation of aryl iodides with amine nucleophiles in the presence of recyclable palladium catalysts immobilised on a supported dicationic ionic liquid phase

Silica modified with organic dicationic moieties proved to be an excellent support for palladium catalysts used in the aminocarbonylation of aryl iodides. By an appropriate choice of the reaction conditions, the same catalyst could be used for selective mono- or double carbonylations leading to amide and [small alpha]-ketoamide products, respectively. The best catalyst could be recycled for at least 10 consecutive runs with a loss of palladium below the detection limit. By the application of the new support, efficient catalyst recycling could be achieved under mild reaction conditions (under low pressure and in a short reaction time). Palladium-leaching data support a mechanism with dissolution-re-precipitation of the active palladium species

Prolinates as secondary amines in aminocarbonylation: Synthesis of N-acylated prolinates

Methyl prolinate and benzyl prolinate were used as secondary amine nucleophiles in palladium catalysed aminocarbonylation of iodo-aromatics and iodo-alkenes. A mixture of 2-oxo-carboxamide and carboxamide type derivatives or pure carboxamides can be obtained by using iodo-benzene or iodo-alkenes as substrates, respectively. The aminocarbonylation of iodo-alkenes in [bmim][PF6] ionic liquid was also carried out. © 2006 Bentham Science Publishers Ltd

Homogeneous catalytic aminocarbonylation of iodoalkenes and iodobenzene with amino acid esters under conventional conditions and in ionic liquids

Amino acid methyl esters were used as amine nucleophiles in palladium catalysed aminocarbonylation of iodobenzene and iodoalkenes (1-iodo-cyclohexene and 17-iodo-androst-16-ene). 2-Oxo-carboxamide type derivatives can be isolated as a result of double CO insertion by using iodobenzene as a substrate at elevated carbon monoxide pressure. On the contrary, carboxamides of expected structure were obtained exclusively in excellent yields in the whole pressure range by using iodoalkenes. The aminocarbonylation of 17-iodo-androst-16-ene in [bmim][PF 6] or [bmim][BF 4] (where bmim=1-butyl-3-methyl- imidazolium cation) ionic liquids was also carried out and the ionic liquid-catalyst mixtures have been reused several times with only a small loss of activity. © 2004 Elsevier Ltd. All rights reserved

Plazmovy lektin klistaka Ornithodoros moubata.

The plasma lectin Dorin M, from the soft tick Ornithodoros moubata, has been studied. Dorin M is the first lectin to be purified and characterized from ticks. This lectin exhibits binding specifity to monosaccharides containing the N-acetyl group such as GlcNAc and GalNAc with N-acetyl-neuraminyl-lactose being the best inhibitor examined. Dorin M belongs to the fibrinogen-related protein family whose members serve as non-self recognizing molecules in many invertebrates. Dorin M play a role in the innate immunity of the tick and possibly also in pathogen transmission by this vector.Available from STL, Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi