Highly enantioselective hydrogenation of N-phthaloyl enamides
摘要:
Rh- or Ru-catalyzed highly enantioselective hydrogenation of N-phthaloyl enamides is presented. Electron-rich Tang-Phos and DuanPhos are found to be effective ligands for Rh-catalyzed hydrogenation of alpha-aryl enamides and up to 99% ee has been achieved. In contrast, for the hydrogenation of alpha-alkyl enamide.. the Ru-C-3-TunePhos complex is more effective and up to 69% ee can be observed. This work is the first report of the hydrogenation of N-phthaloyl enamides. (c) 2005 Elsevier Ltd. All rights reserved.
A series of imidazole-containing (non-)chiral carbamates were tested at human histamine H-3 receptor (H3R). All compounds displayed K-i values below 100 nM. A trend for a stereoselectivity at human H3R was observed for the chiral alpha-branched ligands. Selected compounds were also tested at human histamine H-4 receptor and showed moderate to weak affinities (118-1460 nM). (C) 2009 Elsevier Ltd. All rights reserved.