The enantioselective [3 + 1]-cycloaddition of racemic donor–acceptor (D–A) aziridines with isocyanides was first realized under mild reaction conditions using a chiral N,N′-dioxide/MgII complex as catalyst, providing a facile route to enantioenriched exo-imido azetidines with good to excellent yield (up to 99%) and enantioselectivity (up to 94% ee). An obvious chiral amplification effect was observed