The reactions between the fluoroboranes [(Me3Si)2N]2BF or (Me3Si)2N-BF-N(CMe3)SiMe3 and AlCl3 in diethyl ether afforded the first tri- and disilylated aminoiminoborenes, which were isolated and structurally confirmed as AlCl3 adducts, Me3Si(AlCl3)N=B=N(R)SiMe3, [R = SiMe3 (1), CMe3 (2)]. Density functional theory calculations of 1 and 2 were performed to understand the regioselectivity of the adduct formation.