N-phthalimidoaziridines by diastereoselective Addition to α,β-unsaturated amides: a route to chiral β-substituted α-hydrazino acid derivatives
Abstract
Lead tetraacetate oxidation of N-aminophthalimide 1 in the presence of N-enoylbornane[10,2]sultams (Oppolzer auxiliary) generates corresponding N-phthalimidoaziridine adducts (12–94% yield) with 33% to 95% diastereofacial selectivity (syn attack at the re face of the α-carbon for 4a); these chiral N-aminoaziridine derivatives readily undergo ring opening by sulfur nucleophiles to give α-hydrazino acid derivatives.