N-Heterocyclic carbene-catalyzed diastereoselective synthesis of β-lactone-fused cyclopentanes using homoenolate annulation reaction
作者:Subrata Mukherjee、Santigopal Mondal、Atanu Patra、Rajesh G. Gonnade、Akkattu T. Biju
DOI:10.1039/c5cc02960k
日期:——
NHC-catalyzed annulation of enals with 2-enoylpyridines or 2-enoylpyridine N-oxides leading to the diastereoselective synthesis of [small beta]-lactone-fused cyclopentanes is reported. The reaction proceeds via the generation of homoenolate equivalent intermediates and...
The synthesis and luminescenceproperties are reported for 20 different chelates composed of 2,2′:6′,2″-terpyridine as the energy-absorbing and donating group, EuIIIand TbIII as the emitting ions, methylenenitrilo(acetic acids) as the stabel chelate-forming moieties, and isothiocyanato or(4,6-dichloro-1,3,5-triazin-2-yl)amino groups as the activated moieties for coupling to biomolecules.
Efficient and Clean Aldol Condensation Catalyzed by Sodium Carbonate in Water
作者:Ze Zhang、Ya-Wei Dong、Guan-Wu Wang
DOI:10.1246/cl.2003.966
日期:2003.10
Efficient and environmentally friendly synthesis of chalcone and azachalcone was performed by aldol condensation of aldehydes with ketones in pure water catalyzed by sodium carbonate. In this convenient methodology, side reactions were avoided and thus high yields were achieved.
[11C]-(+)-a-DTBZ has been used as a marker of dopaminergic terminal densities in human striatum and expressed in islet beta cells in the pancreas. We aimed to establish a fully automated and simple procedure for the synthesis of [11C]-(+)-a-DTBZ for routine applications. [11C]-(+)-a-DTBZ was synthesized from a 9-hydroxy precursor in acetone and potassium hydroxide with [11C]-methyl triflate and was purified by solid phase extraction using a Vac tC-18 cartridge. Radiochemical yields based on [11C]-methyl triflate (corrected for decay) were 82.3% ± 3.6%, with a specific radioactivity of 60 GBq/mmol. Time elapsed was less than 20 min from end of bombardment to release of the product for quality control.
Inhibitory potential of some chalcones on cathepsins B, H and L
作者:Shweta Garg、Neera Raghav
DOI:10.1039/c5ra12856k
日期:——
Cathepsins, intracellular proteases, are known to be involved in a number of physiological processes such as degradation of extracellular proteins, prohormone processing, progressions of atherosclerosis etc.