Al(OTf)3 (0.0168 g, 0.036 mmol, 5 mol %) was added to a flask charged with 3-(aminomethyl)-N,N-diethylaniline (0.19 g, 1.07 mmol, 1.5 eq) under Ar. After stirring for 10 min tert-butyl (S)-1-((S)-oxiran-2-yl)-2-phenylethylcarbamate (0.187 g, 0.71 mmol, 1 eq) was added and the mixture was heated to 70° C. for 1 h. After cooling to room temperature the residue was dissolved in EtOAc with a few drops of water. After 20 min of vigorous stirring the mixture was filtered through cotton and dried over Na2SO4. The inorganics were filtered off, and the solvent was removed in vacuo. Purification via flash chromatography yielded 0.0682 g (0.154 mmol, 22% yield) of the product.
