Ligand-Controlled Inversion of Diastereo- and Enantioselectivity
in Silver-Catalyzed Azomethine Ylide–Imine Cycloaddition of
Glycine Aldimino Esters with Imines
A highly
diastereo- and enantioselective silver-catalyzed azomethine
ylide–imine (AYI) cycloaddition reaction of glycine aldimino
esters with imines was developed in which the Xing-Phos-controlled <i>syn</i>-selective or DTBM-Segphos-induced <i>anti</i>-selective AYI cycloaddition reaction could be applied to the synthesis
of a variety of stereodivergent 1-alkyl-2,5-substituted imidazolidines
with high yields and excellent enantioselectivities (up to 99% ee)
as well as good diastereoselectivities (up to 99:1 dr) under mild
reaction conditions
