Phosphinite Thioethers Derived from Chiral Epoxides. Modular <i>P</i>,<i>S</i>-Ligands for Pd-Catalyzed Asymmetric Allylic Substitutions
作者:Xisco Caldentey、Miquel A. Pericàs
DOI:10.1021/jo100223w
日期:2010.4.16
prepared from enantiopure arylglycidols. These ligands have been iteratively optimized with respect to four different structural parameters for use in Pd-catalyzed allylic substitutions. As a final output, highly active and enantioselective ligands for these synthetically important transformations have been developed, and the factors controlling their catalytic behavior have been rationalized. From a methodological
Modular optimization of enantiopure epoxide-derived P,S-ligands for rhodium-catalyzed hydrogenation of dehydroamino acids
作者:Xisco Caldentey、Xacobe C. Cambeiro、Miquel A. Pericàs
DOI:10.1016/j.tet.2011.04.050
日期:2011.6
The optimization of P,S-ligands derived from enantiopure (2S,3S)-phenylglycidol for asymmetric rhodium-catalyzed hydrogenation of dehydroamino esters is described. The exceptionally high modular character of the (25,3S)-phenylglycidol platform is demonstrated by systematic modification of the ether and thioether moieties, the skeletal aryl substituent and the stereo and regiochemistry of the ligands. An experimentally useful method for the monitoring of hydrogenation reactions is also described and used for obtaining relevant data of the catalytic systems studied. (C) 2011 Elsevier Ltd. All rights reserved.