General Procedure A: Kürti Aziridination A 10 mL round-bottom flask was charged with a stir bar, silanol substrate (1 mmol), Rh2(esp)2 (0.023 g, 0.03 mmol, 0.03 equiv.), and trifluoroethanol (5 mL, final reaction concentration of 0.2 M). The reaction flask was cooled to 0 °C using an ice-water bath. Subsequently, hydroxylamine-O-sulfonic acid (HOSA) (0.147 g, 1.3 mmol, 1.3 equiv.) and pyridine (0.105 ml, 0.103 g, 1.3 mmol, 1.3 equiv.) were added. The reaction mixture was allowed to warm to room temperature over a period of 16 hours. Following this time, the mixture was diluted with CH2Cl2, transferred to a separatory funnel, and washed with one portion of saturated, aqueous NaHCO3 solution. The organic layer was collected, dried over MgSO4, and concentrated under reduced pressure. The resulting residue was purified by chromatography on silica gel (gradient of 0 to 100% acetone/CH2Cl2). Note: quantities are given for a 1 mmol reaction and are changed appropriately with changes in scale.