Combinatorial approach to chiral tris-ligated carbophilic platinum complexes: application to asymmetric catalysis.
A straightforward methodology for the synthesis of libraries of chiral tris-ligated cationic platinum complexes and their in situ evaluation as asymmetric carbophilic catalysts in a model domino hydroarylation/cyclization reaction of a 1,6-enyne was developed. A catalyst-generation process based on a combination of a monodentate and a bidentate phosphorus ligand allowed the formation of 108 chiral complexes. One-pot screening of the stereoinduction obtained with this library in a test domino addition/cyclization reaction validated this approach and stressed the key role played by the monodentate ligand partner in obtaining high enantioselectivities. In the case of two challenging substrate/nucleophile combinations, the combinatorial approach resulted in a significant gain in enantioselectivity.
Institut de Recherche de Chimie Paris, UMR 8247, Chimie ParisTech, ENSCP, 11, rue Pierre et Marie Curie, 75231 Paris CEDEX 05 (France), Fax: (+33) 144071062.
Alexandre
A
Pradal
Serafino
S
Gladiali
Veronique
V
Michelet
Patrick Y
PY
Toullec
P ligands; asymmetric catalysis; combinatorial chemistry; cyclization; platinum