Iodine-oxygen bonds

Iodanes with Only Iodine-Oxygen Bonds Non-Cyclic. 73... 

Iodanes with only Iodine-Oxygen Bonds Cyclic. 76... 

REAGENTS WITH IODINE-OXYGEN BONDS 12.2.1 [Hydroxy(phosphoryloxy)iodo]benzenes... 

Some Further Reagents of Iodine (III) o-Iodosylbenzoic Acid and Its Derivatives. Reagents with Iodine-Oxygen Bonds. Reagents with Iodine-Nitrogen Bonds. 

Recent developments in this area include the use of poly[hydroxy(tosyloxy)-iodo]styrenes [80], chiral 2-(a-alkoxyalkyl) analogs of [hydroxy(tosyloxy)-iodo]benzene [81 - 83], and iodine(III)-phosphonate and -phosphinate reagents [84] for C-oxygen bond formation at a-carbon. Oxysulfonylations at the a-carbon atoms of carboxylic anhydrides with [hydroxy(sulfonyloxy)iodo]arenes have also been documented [85]. 

The use of a catalytic amount of iodine in acetone was found to effect the addition of isopropylidene cyclic acetals to a wide variety of mono-199 and disaccharides.200 In the case of disaccharides, some cleavage of the glycosidic link was also observed. The proposed rationale for this acetalation is that iodine, acting as a Lewis acid, polarizes the carbon-oxygen bond (Scheme 42), increasing the electrophilicity of the carbon, leading to dehydration. In this instance, the iodine acts in the same manner as a proton in the acid-catalyzed introduction of a cyclic acetal. Hydroiodic... 

Zirconium-aryne complexes have also found application in the regiose-lective synthesis of halophenols.62 Reaction of 101 with methyl diethylbori-nate or triethylborate leads to insertion of a boron-oxygen bond into a Zr-benzyne bond with formation of 102 and 104, respectively (Scheme 12). Further reactions of 102 and 104 with bromine or iodine followed by excess NaOH and 30% hydrogen peroxide gives halomethyl(methoxy)phe-nols 103 and 105 in good yields. In most cases only one regioisomer of the halophenol was observed. 

The mechanism by which a nitrate group on a primary carbon atom is replaced by iodine clearly involves the rupture of the carbon-oxygen bond illustrated earlier in this Section. What happens when a secondary nitrate group is replaced by a hydroxyl group is more obscure, but one suggestion is that the oxygen-nitrogen bond breaks as follows. 

An alternative approach is to use the readily available P-hydroxy phenyl selenides as Ritter substrates. Amide formation occurs with retention of configuration, indicating that fission of the carbon-oxygen bond is assisted by the neighboring phenylseleno group (Scheme 61). Diphenyl diselenide and iodine react with 1,5-dienes to give carbocyclic products. Initial formation of the episelenonium ion is followed by intramolecular attack and subsequent Ritter reaction (Scheme 62). ... 

Boyd et al. [46] have studied the y-radiolysis of several oxyhalides. The extent of reaction in the Group lA and thallium bromates increased linearly with dose, yielding BrOj, BrO", Br and in proportions which depended on the cation present. Later work extended the reactants to KCCOj (products CCO, CCO jUnd O ), CsBrO 3 (products BrO" and O3 ) and CSIO3 (increased absorption was ascribed to molecular iodine in the crystal). It was concluded that reaction within the crystal is initiated by ionization, with excitation of the oxyhalide ion, followed by rupture of the halogen-oxygen bond ... 

The reactions of compounds with silicon-oxygen bonds continue to attract interest. A two-dimensional Si NMR study of the species present in 1.5 mol dm of potassium silicate indicates the presence of 22 different species, clear evidence of the complexity of such systems. The kinetics of the hydrolysis and self-condensa-tion reactions of (MeO)3SiMe have been studied.Iodine catalyzes the forward and back reactions in equation (21). Radicals derived from... 

Various oxygen-bonded iodine(V) derivatives are known [641-643]. Iodine pentoxide, I2O5, the most important and thermally stable iodine oxide, is prepared in the form of a hygroscopic, white solid by dehydration of iodic acid, HIO3, at 200 °C. It readily absorbs water from the atmosphere, giving the hydrate,... 

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