Synthesis and Stereoselective Lithiation of Enantiopure 2‐(1‐Aminoalkyl)aziridine–Borane Complexes

Two alternative methodologies can be used to obtain enantiopure aziridine–borane complexes 2: successive treatment of 2-(1-aminoalkyl)aziridines 1 with BF3⋅Et2O and LiAlH4 or by direct reaction with BH3⋅THF (see scheme, Bn=benzyl). The complexes 2 can be deuterated or silylated highly stereoselectively at C3 by reaction with sBuLi and subsequent treatment with D2O or ClSiMe3, respectively.