Furrocene-based chiral phosphine-triazines: A new family of highly efficient P,N ligands for asymmetric catalysis

The presence of the additional heterocyclic nitrogen atoms in chiral PN ligands has an important influence on the asymmetric catalysis, and a clear trend was observed in the present research that the enantioselectivity and reactivity were significantly increased by raising the number of heterocyclic nitrogen atoms in these PN ligands. Through finely tuning the number of heterocyclic nitrogen atoms, a new family of ferrocene-based chiral phosphine-triazine ligands with three heterocyclic nitrogen atoms has been developed and successfully applied in Pd-catalyzed asymmetric allylic substitution. Up to 99% ee with 99% yield of allylic alkylation products and 94% ee of allylic amination products have been obtained by the use of ligand (R-c,S-p)-1f with a 4,6-diphenoxy-1,3,5-triazine moiety.