A strongly positive dendrimer effect in asymmetric catalysis: allylic aminations with Pyrphos-palladium functionalised PPI and PAMAM dendrimers.
A remarkable and unprecedented increase in catalyst selectivity in dendrimer catalysis is observed for the Pyrphos-Pd catalysed allylic amination of 1,3-diphenyl-1-acetoxypropene as a function of the dendrimer generation (with up to 64 metal sites). This steady increase in ee-values for the allylic amination is less pronounced for the poly(propyleneimine)-derived catalysts than for the corresponding palladium-PAMAM dendrimer catalysts for which an increase in selectivity from 9% ee for a mononuclear reference system to 69% ee for the Pd64-dendrimer was found.
Ribourdouille
Yann
Y
Laboratoire de Chimie Organométallique et de Catalyse, UMR 7513, Institut Le Bel, Université Louis Pasteur, 67070 Strasbourg, France.
Engel
Gerald D
GD
Richard-Plouet
Mireille
M
Gade
Lutz H
LH