Use of Hypervalent Iodine Derivatives

Examples of the former take place when radical 234 is stabilized by a heteroatom. When Y is an alkoxy moiety, an oxonium is formed and trapped by several external nucleophiles [193]. When an amide was present on the starting material, as was the case with 235, amino sugars were obtained in good yields (68% for 238) [ 194]. Finally, when Y is an azide, oxidation to the a-azido cation delivers nitriles upon loss of nitrogen [195]. 

The reaction follows the latter pathway when oxidation of radical 234 is not so easy. In those cases, an alternate course involving iodine atom transfer to the substrate is followed. This allows the formation of iodoalditols [196,197], difluoroalditols (241, 75%) [198], vinyl azides [199], or vinyl sulfones (although in that particular case, the mechanism may be more sophisticated due to the possible 6-elimination of the sulfur group) [200]. 

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Both sarin and soman react with aqueous KHSO5 to produce the corresponding phosphonic acids (Yang et al., 1992). Valuable studies of the use of hypervalent iodine derivatives (below) to hydrolyze phosphorus esters have been reported (Moss et al., 1983, 1984, 1986 Katritzky et al., 1988). 

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