Experimental procedure:
N-Ts alkenamide (0.1 mmol) and
D5160-CuOAc complex (7.0 mg, 0.01 mmol) are dissolved in dichloromethane (1 mL) and toluene (3 mL). The mixture is stirred at room temperature for 10 min, and at -78 °C for 30 min. Then,
NIS (24.6 mg, 0.11 mmol) and
I2 (5.1 mg, 0.02 mmol) are added to the reaction mixture. After being stirred for 16-18 h, the reaction mixture is quenched with saturated Na
2SO
3 aq. and then the products are extracted with dichloromethane in 3 times. The collected organic layer is dried over Na
2SO
4. After removal of the solvent under reduced pressure, the residue is purified by silica-gel column chromatography (hexane:ethyl acetate = 3:1) to afford the iodocyclization product.