Search

A study was conducted to characterize the structure and stability of hypervalent iodine heterocycles, specifically novel 1-substituted benziodazoles. Acetoxybenziodazole was determined through an oxidation of 2-iodobenzamide with peracetic acid. Results indicated that reaction of alcohols and triflate supported unique 1-alkoxy-3-iminiumbenziodoxoles. Findings also showed that the driving force of the benziodazole rearrangement was greater than the thermodynamic stability of the N-protonated 3-iminobenziodoxoles.

Oxidation with peroxytrifluoroacetic acid and subsequent reaction with TsOH, MsOH or Me3SiOTf are the two steps in the preparation of 1-(hydroxy(sulfonyloxy)iodo)-1H-1H-perfluoroalkanes, a new structural type of iodine(III)sulfonate. A reactivity pattern similar to Koser's reagent is observed in the compounds, making them useful for vicinal oxytosylations and for the synthesis of alpha-(tosyloxy) ketones. The analogous triflates react with (trimethylsilyl)arenes under mild conditions to produce the corresponding (fluoroalkyl) (aryl)iodonium triflates. The analogous reaction with alkynyltrimethylsilanes results in new (fluoroalkyl)(alkynyl)iodonium salts.

The preparation of sulfonates 1,2-benziodoxol-3(1H)-one and 3,3-bis(trifluoromethyl)-3(1H)-1,2-benziodoxole is described. The utilization of triflate derivatives as electrophilic reagents for the preparation of alkynyliodonium salts via the reaction with (trimethylsilyl)alkynes is also reported. Organosulfonyloxy derivatives of the sulfonates can be prepared by the reaction of 1-hydroxybenziodoxoles and the corresponding sulfonic acids or Me3SiOTf in the form of microcrystalline solids.

The synthesis of bis(phenyliodonium) diyne triflates allows the study of their structure and chemistry. Their preparation involves iodononium transfer from cyanophenyliodonium triflate to the proper tributyltin diacetylenes in dichloromethane at -78 degrees C. Warming to room temperature produces the stable microcrystals in 78-93% yields. The iodononium salts are characterized by nuclear magnetic resonance and infrared spectroscopies. Under mild conditions, they lose their iodobenzene ring to triphenylphosphine to yield bisphosphonium salts.

[Bis(trifluoroacetoxy)iodo]perfluoroalkanes [C.sub.n][F.sub.2n+1]I[(OCOC[F.sub.3]).sub.2] is prepared by the oxidation of the corresponding perfluoroalkyl iodides with Oxone in trifluoroacetic acid at room temperature and converted to the stable [hydroxyl(tosyloxy)iodo]perfluoroalkanes by treatment with p-toluenesulfonic acid. This method is extended to the preparation of various [bis(trifluoroacetoxy)iodo]arenes.

New tosyl derivatives of 2-iodylaniline and 2-iodylphenol are prepared by the dimethyldioxirane oxidation of the corresponding 2-iodophenyltosylamides or 2-iodophenyl tosylate and isolated as stable, microcrystalline products. Single-crystal X-ray diffraction analysis of N-(2-iodylphenyl)-N,4-dimethylbenzenesulfonamide has shown pseudocyclic structure formed by intramolecular IaO interactions between the hypervalent iodine center and the sulfonyl oxygens in the tosyl group.

Intramolecular Diels-Alder reaction of Furan (IMADAF) of 1-acyl-1-alkylamino(furan-2-yl)-methyl phosphonates results in complex azaheterocyclic phosphonates in a small number of synthetic steps. These products can be used as novel conformationally constrained amino acid analogues.

The synthesis and structural characteristics and reactivity of recyclable iodine reagents obtained from 3-iodosylbenzoic acids are described. The compounds are isolated as white, microcrystalline compounds and studied using NMR spectroscopy, elemental analysis and x-ray crystallography.

The preparation of polymer-supported analogues of 2-iodylphenol ethers by using commercially available aminomethylated polystyrene and Merrifields' resin is described.

New facile methodology for the preparation of pentavalent iodine compounds is described, using peracetic acid as an oxidant in the presence of catalytic amounts of ruthenium trichloride. The new procedure allows the preparation of several previously unknown iodylarenes bearing strongly electron-withdrawing C[F.sub.3] groups in the aromatic ring as well as the preparation of the sterically hindered 1-iodyl-2-isopropylbenzene.

2-Iodylphenol ethers were prepared by the dimetnyldioxirane oxidation of the corresponding 2-iodophenol ethers and isolated as chemically stable microcrystalline products. Single crystal X-ray diffraction analysis revealed pseudopolymeric arrangements in the solid state formed by interactions between I[O.sub.2] groups of different molecules and 2-iodylpehnol ethers can selectively oxidize sulfides to sulfoxides and alcohols to the respective aldehydes or ketones.

Esters of 2-iodoxybenzoic acid (IBX)-esters) were prepared by the hypochlorite oxidation of the corresponding 2-iodobenzoate esters and isolated as chemically stable, microcrystalline products. The dimethyl and diisopropyl esters of 2-iodoxybenzoic acid were prepared by oxidation of the respective iodoarenes with dimethyl-dioxirane.

A new pseudocyclic hypervalent iodine reagent, benziodoxole triflate (IBA-OTf, a complex of 2-iodosylbenzoic acid with trifluoromethanesulfonic acid), can be used as an efficient oxidant for selective oxidation of various organic sulfides to sulfoxides. This oxidation proceeds under mild condition to afford the corresponding sulfoxides in moderate to good yields without overoxidation. The reduced form of the hypervalent iodine reagent, 2-iodobenzoic acid, can be easily recovered from the reaction mixture in good yields by a simple acidbase liquid-liquid biphasic protocol. [ABSTRACT FROM AUTHOR]