Hypervalent Iodine in Synthesis. Part 90. A Mild and Efficient Method for the Iodination of Pyrazoles.

Abstract

Pyrazole derivatives Pyrazole derivatives R 0180Hypervalent Iodine in Synthesis. Part 90. A Mild and Efficient Method for the Iodination of Pyrazoles. -Iodobenzene diacetate combined with iodine is used as a mild and effective reagent for the iodination of pyrazoles (I). Polymer-supported diacetate can also be used for the reaction.

Potassium 4-Iodylbenzenesulfonate (PIBS): An Efficient Recyclable Hypervalent Iodine Reagent for Iodo-functionalization of Alkenes, Alkynes and Ketones

“…Particularly important are the applications of hypervalent iodine reagents, such as, (diacetoxyiodo)benzene or derivatives of benziodoxole, in oxidative iodination reactions. For example, various aryl iodides can be conveniently prepared by iodination of arenes in the presence of organoiodine(III) or organoiodine(V) oxidants [20][21][22][23][24][25][26][27][28]. However, despite their importance, the common hypervalent iodine(III) and iodine(V) reagents (e.g., diacetoxyiodobenzene or 2-iodoxybenzoic) have a serious disadvantage with respect to the principles of Green Chemistry since they are normally used as the non-recyclable, stoichiometric reagents.…”