Asymmetric hydrogenation of an α-unsaturated carboxylic acid catalyzed by intact chiral transition metal carbonyl clusters – diastereomeric control of enantioselectivity
Synthesis of a Spiroindolinone Pyrrolidinecarboxamide MDM2 Antagonist
摘要:
A practical synthesis of a spiroindolinone pyrrolidinecarboxamide MDM2 antagonist 2 is reported. Cycloaddition of dipolarophile 3 with imine 30 afforded a complex mixture of diastereomers that were isomerized to the desired stereoisomer 31 by heating the mixture in the presence of DBU. After hydrolysis, the resulting product was resolved with a chiral amine to give an enantiopure acid which was converted to the target product 2. The process has been scaled up to a multihundred-gram scale. In addition, an asymmetric synthesis of 31 catalyzed by AgOAc and a chiral phosphine ligand was developed to give enantiomerically enriched 31, which was also converted to enantiopure 2.
Electrochemistry and complexation of Josiphos ligands
作者:Brenna L. Ghent、Sarah L. Martinak、Lauren A. Sites、James A. Golen、Arnold L. Rheingold、Chip Nataro
DOI:10.1016/j.jorganchem.2007.02.039
日期:2007.5
The oxidative electrochemistry of 11 chiral bis-phosphinoferrocene ligands, all within the Josiphos class of ligands, was examined in methylene chloride. The oxidation of these ligands displays multiple waves of varying chemical reversibility. Palladium(II) and platinum(II) complexes with the general formula [MCl2(P–P)] (M = Pd or Pt; P–P = Josiphos) were prepared, characterized by NMR and cyclic voltammetry