The firstcatalytic enantioselective Roskamp reaction of alpha-alkyl-alpha-diazoesters with aromaticaldehydes was realized using a simple chiral N,N'-dioxide-scandium(III) complex. Remarkably, with 0.05 mol % catalyst, the reaction was performed well over a series of substrates, giving the desired products chemoselectively in excellent yields (up to 99%) and enantioselectivities (up to 98% ee) under