Amination of N-Aryl Prolinol via Ring Expansion and Contraction: Application to the Chiral Ligand for the Catalytic Asymmetric Reaction
摘要:
Chiral diaminophosphines 4 were prepared from (S)-prolinol-derived aminophosphine oxide 5 by bromination with ring expansion followed by amination with ring contraction and reduction, using trichlorosilane. In the presence of 4 as ligand, palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate (11) with a dialkyl malonate-BSA-LiOAc system was successfully carried out with good enantioselectivities (up to 98% ee).
Amination of N-Aryl Prolinol via Ring Expansion and Contraction: Application to the Chiral Ligand for the Catalytic Asymmetric Reaction
摘要:
Chiral diaminophosphines 4 were prepared from (S)-prolinol-derived aminophosphine oxide 5 by bromination with ring expansion followed by amination with ring contraction and reduction, using trichlorosilane. In the presence of 4 as ligand, palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate (11) with a dialkyl malonate-BSA-LiOAc system was successfully carried out with good enantioselectivities (up to 98% ee).
New type chiral ligands 3, which have a chiral carbon center and stable C(aryl)-N(amine) axial chirality, were prepared from chiral prolinol-derived aminophosphine oxide 4. Pd-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate (6) with a dimethyl malonate-BSA-LiOAc system was successfully carried out in the presence of 3d resulting in a good yield with good enantioselectivity (up to 95% ee). (C) 2003 Elsevier Science Ltd. All rights reserved.
Amination of <i>N</i>-Aryl Prolinol via Ring Expansion and Contraction: Application to the Chiral Ligand for the Catalytic Asymmetric Reaction
Chiral diaminophosphines 4 were prepared from (S)-prolinol-derived aminophosphine oxide 5 by bromination with ring expansion followed by amination with ring contraction and reduction, using trichlorosilane. In the presence of 4 as ligand, palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate (11) with a dialkyl malonate-BSA-LiOAc system was successfully carried out with good enantioselectivities (up to 98% ee).