N-Benzyloxycarbonylamino sulfones react with aromatic ketones in the presence of catalytic amount of boron trifluoride-diethyl ether at room temperature to afford the corresponding protected β-amino ketones in high yields (71-87%). α-amido sulfones - stable imine precursors - aromatic ketones - BF3˙OEt2 - Lewis acids - β-amino ketones Part 200 in the series ‘Studies on Novel Synthetic Methodologies’