New Schiff bases derived from chiral d‐camphor were determined to be effective phosphine ligands for the asymmetric palladium‐catalyzed allylic alkylation of activated methylene compounds, the allylic etherification of alcohols, and the allylic amination of primary amines or secondary amines, in which the corresponding products with various functional groups were achieved in good yields with excellent
Changing the Palladium Coordination to Phosphinoimidazolines with a Remote Triazole Substituent
作者:Verónica de la Fuente、Rocío Marcos、Xacobe C. Cambeiro、Sergio Castillón、Carmen Claver、Miquel A. Pericàs
DOI:10.1002/adsc.201100684
日期:2011.12
Phosphinoimidazoline (PHIM) ligands bearing a triazolylmethyl substituent at the sp3 nitrogen atom in the imidazoline ring lead to highly improved enantioselectivity (up to 99% ee) in allylic substitution reactions with respect to analogous ligands with substituents lacking the triazole unit. NMR and theoretical studies support a shift in the coordination mode of the PHIM ligand to palladium, triggered