Abstract
The direct three-component asymmetric Mannich reactions of hydroxyacetone with anilines and aromatic aldehydes in the presence of (2S,5S)-5-(methoxycarbonyl)pyrrolidine-2-carboxylic acid afforded syn-1,2-amino alcohols in good-to-excellent yields (55∼91%) and up to 98% ee.
ACKNOWLEDGMENT
We thank the National Natural Science Foundation of China (20402004) and the Science Foundation of Shanghai Municipality (06ZR14028) for financial support.
Notes
a Isolated yield after silica-gel column chromatography.
b Determined by HPLC analysis.
c Ee values of syn-isomer, determined by HPLC using chiralpak AD-H column.
d 4 Å Molecular sieves were added.
e The reaction was carried out at 10 °C.
f Performed imine was used.
a Isolated yield after column chromatography.
b Determined by HPLC analysis.
c Enantiomeric excess of syn-product was determined by HPLC using Chiralcel OD-H or Chiralpak AD-H column.
a Isolated yield after silica-gel column chromatography.
b Determined by HPLC analysis.
c Ee values of syn-isomer, determined by HPLC using Chiralpak AD-H column.