Chiral phosphite–phosphoroamidites: a new class of ligand for asymmetric catalytic hydrogenation
作者:Montserrat Diéguez、Aurora Ruiz、Carmen Claver
DOI:10.1039/b109043g
日期:2001.12.19
A series of novel phosphite–phosphoroamidite ligands, derived from readily available D-xylose, has been used for the first time in the asymmetric Rh-catalyzed hydrogenation of a series of α,β-unsaturated carboxylic acid derivatives with excellent enantioselectivity (ee up to >99%).
Chiral furanoside phosphite–phosphoroamidites: new ligands for asymmetric catalytic hydroformylation
作者:Montserrat Diéguez、Aurora Ruiz、Carmen Claver
DOI:10.1016/s0957-4166(01)00489-x
日期:2001.11
We have designed a new series of phosphite phosphoroamidites ligands 1 4 based on a furanoside backbone. These ligands were screened in the Rh-catalyzed asymmetric hydroformylation of styrene, inducing high regioselectivities with 2-phenylpropanal md moderate enantioselectivities (up to 65%, c.e.). The results showed that the configuration of the stereogenic carbon atom C(3) at the ligand backbone had remarkable effects on the activity and enantioselectivity. Replacing the tert-butyl substituents with methoxy substituents at the para positions of the biphenyl moieties improved the enantioselectivities. We have also studied the solution structures of HRh(PP)(CO)(2) complexes. (C) 2001 Elsevier Science Ltd. All rights reserved.