An organoaluminum-free and catalyst-free anti-carboalumination of alkynes using aluminum trihalides and silyl ketene imines was developed. Three components, an alkyne, AlX, and a silyl ketene imine, were simply mixed to give the alkenylaluminum bearing a cyano group with regioselectivity. Theoretical calculations revealed the effective activation of the alkyne by AlX to enhance the regioselective carboalumination. The synthesized alkenylaluminums were applicable to many organic transformations.