Scandium phosphate catalyst

The enantioselective conjugate addition of hydroxylamines to a range of a, 3-carbonyls occurs with moderate to good ee in the presence of Lewis acidic magnesium- and zinc-based bis-oxazo lines, and with high ee using the scandium-phosphate catalyst (11.124). ... 

Conjugate addition of O-alkylhydroxylamines to a,P-unsaturated ketones was effectively catalyzed by an isolable complex of scandium with a chiral phosphate ligand (Sc[(R)-BNP]3) [124]. The corresponding P-amino ketones were generated in almost quantitative yields with high enantioselectivities (Scheme 12.48). These products could be quantitatively converted into the 2-acyl aziridines upon treatment with a base catalyst without losing their enantiopurities. 

A novel scandium complex bearing perfluorinated binaphthyl phosphate ligand, Sc[(R)-F8BNP]3, has been synthesized and used as a catalyst for asymmetric electrophilic fluorination reactions of P-keto esters [156]. In combination with 1-fluoro-pyridinium triflate (NFPY-OTf) as a fluorinating agent, the desired a-fluoro-P-keto esters were obtained in moderate to high yields (16-94%) and enantiomeric excesses (47-88%) under mild conditions. 

---