Electrophilic Iodinating Reagent

N-Iodosaccharin (1), which was reported by Dolenc, is an effective electrophilic iodinating reagent. 1 is a stable compound, and soluble in common polar organic solvents, such as acetone or acetonitrile. 1 shows higher reactivity and selectivity than other iodinating reagents, such as N-iodosuccinimide (NIS), which is frequently used for iodination. For example, 1 reacts smoothly with activated aromatics such as anilines and phenols in good yields. Hydroxy and formyl groups do not react under the reaction conditions.

Moreover, 1 smoothly iodinates alkenes to afford the corresponding adducts of iodine in good yields. It is noted that additions follow the Markovnikov rule with very high regioselectivity. Thus, 1 works as a moderately electrophilic iodinating reagent, which can be used under neutral conditions.