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

Abstract

Potassium 4-iodylbenzenesulfonate (PIBS) is a thermally stable and water soluble hypervalent iodine oxidant particularly useful as a recyclable reagent for oxidative iodination of alkenes, alkynes and ketones. This reagent can be effectively recovered from the reaction mixture by treatment of the aqueous layer with Oxone at 60 o C followed by filtration of the precipitate.

Recyclable Hypervalent Iodine Reagents in Modern Organic Synthesis

“…93 Zhdankin et al also reported the synthesis of the recyclable and water-soluble I(V) reagent potassium 4-iodylbenzenesulfonate (PIBS) (204) via the oxidation of 4-iodobenzenesulfonic acid using Oxone ® in water. 94 This watersoluble reagent can be used for the oxidative iodination of arenes, 94 alkenes, 95 alkynes, 95 and ketones 95 (Scheme 40). Unreacted PIBS (204) and its reduced form PIBS-H can be recovered from the reaction mixture.…”

“…Unreacted PIBS ( 204 ) and its reduced form PIBS-H can be recovered from the reaction mixture. 94 95…”

“…To overcome this limitation, various recyclable HVI(V) reagents have been reported in the literature. 90 91 92 93 94 95 96 97 98 99 The structures of these reagents are shown in Figure 10 .…”

“…To overcome this limitation, various recyclable HVI(V) reagents have been reported in the literature. [90][91][92][93][94][95][96][97][98][99] The structures of these reagents are shown in Figure 10. In 2002, Thottumkara reported modified 2-iodoxybenzoic acid (mIBX) (202) as an efficient reagent for the oxidation of allylic and benzylic alcohols in water, affording the corresponding aldehydes in 60-96% yield.…”

“…Unreacted PIBS (204) and its reduced form PIBS-H can be recovered from the reaction mixture. 94,95 In an example reported by Sharma and co-workers, the HVI(V) reagent IBX and choline chloride/urea solvent were recycled in a three-component Ugi reaction. The reduced form of IBX can be recovered from the reaction mixture by filtration and converted back into IBX by treatment with aqueous Oxone ® .…”