Applications of aziridinium ions.: Selective syntheses of α,β-diamino esters, α-sulfanyl-β-amino esters, β-lactams, and 1,5-benzodiazepin-2-one

[GRAPHICS] A variety of nucleophiles, including amines, thiolates, and alkoxides, were employed to open the aziridinium ions Az. The latter are opened stereospecifically and regioselectively at the C-3 position by a wide range of amines, and thiolate nucleophiles attack predominately at the C-2 position. Poor regioselectivities (ca. 1:1) were observed using nucleophiles derived from phenols, carboxylic acids, and imides. Base-mediated ring closure of the aziridinium opening products, from primary amines, gave beta -lactams and a 1,5-benzodiazepin-2 one in high yields.