Skip to Main content Skip to Navigation
Theses

Synthèse de nouvelles diphosphines et nouveaux phosphoramidites dissymétriques chiraux par atropoisomérie : étude de leurs propriétés en catalyse asymétrique

Jonathan Madec
Abstract : This manuscript concerns the development of a versatile approach to new and chiral unsymmetric atropisomeric mondentate and bidentate phosphorus ligands, devoid of C2-symmetry in the biaryl scaffold. The optically pure unsymmetrical biaryl moiety is obtained by a known stereoselective coupling reaction between two aryl groups connected by a chiral tether, though ether linkages. Our first target was the synthesis of two new unsymmetric atropisomeric diphosphines which combines the naphtyl, methoxyphenyl and trimethylphenyl fragments of BINAP, MeO-BIPHEP and HexaPHEMP, respectively. MeO-NAPhePHOS and TriMe-NAPhePHOS represent the first examples of atropisomeric diphosphines bearing heterotopic biaryl moieties. The catalytic efficiency of these ligands in enantioselective catalysis has been settled. Thus, MeONAPhePHOS and TriMe-NAPhePHOS have proved to be very efficient in ruthenium-catalyzed asymmetric hydrogenation, in rhodium-mediated 1,4-addition of organoboronic derivatives on α,βunsaturated ketones and in palladium-catalyzed cycloisomerization of 1,7-enynes. Furthermore, we have evaluated their structural properties via molecular modeling calculations and established a correlation between the dihedral angle θ of the diphosphines and the observed enantioselectivities in ruthenium-promoted asymmetric hydrogenation reactions of prochiral ketoesters and olefins. In this comparatice study, we have compared our two unsymmetric ligands with two other atropisomeric diphosphines: BINAP and MeO-BIPHEP. In a second part, we have developped the synthesis of new unsymmetric atropisomeric phosphoramidite ligands whose particuliarity is the lake of C2 symmetry in their biaryl scaffold. Preliminary studies of the role of the new sterogenic phosphorus in rhodium-catalyzed asymmetric hydrogenation and in rhodium-mediated 1,4-addition of organoboronic derivatives on enones has been settleed as well.
Document type :
Theses
Complete list of metadatas

https://pastel.archives-ouvertes.fr/pastel-00001086
Contributor : Ecole Chimie Paristech <>
Submitted on : Tuesday, March 1, 2005 - 8:00:00 AM
Last modification on : Tuesday, March 1, 2005 - 8:00:00 AM
Long-term archiving on: : Thursday, September 30, 2010 - 6:32:15 PM

Identifiers

  • HAL Id : pastel-00001086, version 1

Collections

Citation

Jonathan Madec. Synthèse de nouvelles diphosphines et nouveaux phosphoramidites dissymétriques chiraux par atropoisomérie : étude de leurs propriétés en catalyse asymétrique. Chemical Sciences. Chimie ParisTech, 2004. English. ⟨pastel-00001086⟩

Share

Metrics

Record views

405

Files downloads

4046