Branch point: A simple primary amine thiourea catalyzed highly enantioselective conjugate addition of α,α-disubstituted aldehydes to maleimides has been developed. The biologically useful chiral disubstituted α-branched succinimides are attained with the generation of two contiguous quaternary and/or tertiary stereogenic centers in one step with excellent enantioselectivities and in high yields under mild reaction conditions (see scheme).