Synthesis of Versatile Building Blocks through Asymmetric Hydrogenation of Functionalized Itaconic Acid Mono‐Esters
作者:Koen F. W. Hekking、Laurent Lefort、André H. M. de Vries、Floris L. van Delft、Hans E. Schoemaker、Johannes G. de Vries、Floris P. J. T. Rutjes
DOI:10.1002/adsc.200700307
日期:2008.1.4
The rhodium-catalyzed asymmetric hydrogenation of several β-substituted itaconic acid monoesters, using a library of monodentate phosphoramidite and phosphite ligands is described. Two β-alkyl-substituted substrates were readily hydrogenated by the rhodium complex Rh(COD)2BF4 in combination with (S)-PipPhos as a ligand resulting in ees of 99 %. In contrast, the corresponding more hindered β-aryl-substituted