General Procedure for Tethered Silanoxyselenylation 0.1 mmol scale: An oven dried tube equipped with a magnetic stir bar was charged with allylic silanol starting material (0.1 mmol) and 0.5 mL CH2Cl2. Next, 10-camphorsulfonic acid (0.1 mmol, 23 mg, 1.0 equiv.), N-(Phenylseleno)phthalimide (0.15 mmol, 45 mg, 1.5 equiv.), and 0.5 mL CH2Cl2 were added to the above solution sequentially (Final reaction concentration: 0.1 M). The mixture was stirred at room temperature and monitored by thin layer chromatography (TLC). After 2.0 h, the reaction mixture was diluted with 5 mL CH2Cl2, transferred to a separatory funnel, and washed with 0.5 M aqueous NaOH solution. The organic layer was separated, dried over MgSO4, concentrated in vacuo.