The highly enantioselective Mannich reaction of diazoacetate esters with N-Boc aldimines catalyzed by silver(I) triflate in the presence of (R)-DM-SEGPHOS is reported. The reaction is broad in scope with respect to the (hetero)aromatic aldehyde-derived aldimine and tolerates significant variability of the diazoacetate ester component. Yields and enantioselectivities are good to excellent, and the reaction can be performed on a gram scale with catalyst loadings as low as 1 mol %.