Scope of Al₂O₃/NIS mediated iodination^a.

^aReaction conditions: 1 (2.0 mmol), 2a (2.2 mmol), 4 Å MS (200 mg), Al₂O₃ (2.6 mmol), CH₃CN (10 mL), 80 °C, 1 h. Isolated yields are given. The values in parentheses are the yields of reaction conducted in 2 mL CH₃CN in the absent of 4 Å MS.