Michael-type hydroamination of acrylonitrile, phenyl vinyl sulfone and dimethyl maleate were realized using arylamines catalyzed independently by Yb(OTf)3 and Tb(OTf)3 to give the desired β-amino acid derivatives or β-amino sulfones in moderate to excellent yields. The reactions were carried out in toluene for Yb(OTf)3 and in t-BuOMe for Tb(OTf)3, all carried out at 100 oC.