An efficient catalytic asymmetric [2+2] cycloadditionreaction of allenyl imide and alkenes was achieved by utilizing chiral N,N′-dioxide-magnesium(II) complex as the catalyst. This protocol provided a series of axially chiral cyclobutenes in high yields with excellent enantioselectivities. A stepwise mechanism was proposed based on experimental studies and DFT calculations and π–π stacking interaction