Browsing by Author "Larson, Scott"

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    Preparation and structure of diaryliodonium salts with hydroxy and carboxylic acid groups
    (2022-01) Larson, Scott
    Toxic transition metals are often used in organic synthesis reactions, which poses a potential hazard in their applications, especially medicinally and environmentally. A potential solution to this problem is to use trivalent iodine in place of toxic transition metals in synthesis. One class of compounds that could be specifically useful in toxic transition metal replacement is pseudo-cyclic iodonium triflate salts. This project focuses on developing the best method and scope for the preparation of diaryliodonium salts from iodosobenzoic acid-triflate (IBA-OTf) and (3-acetoxyphenyl)-3-iodanediyl diacetate compounds. These compounds could be used in oxidation reactions, replacing commonly used transition metals and would be safer and more environmentally friendly reagents. The preparing of these diaryliodonium salts can be optimized since there are various possible synthesis conditions available. It was important to find optimal methods for preparing diaryliodonium salts, while avoiding the use of toxic transition metals. In the production of pseudocyclic diaryliodonium triflate salts, an acid activated pseudocyclic hypervalent iodine reagent, 2-[hydroxy(trifluoromethanesufonyloxy)]- iodobenzoic acid, can react easily with various arenes in the presence of trifluoromethanesulfonic acid. The synthesis of the pseudocyclic diaryliodonium triflate salts occurs under mild conditions to obtain the iodonium salts in moderate to good yields. Cyclic iodine (III) compounds, arylbenziodoxolones, can be produced in moderate to good yield by reacting pseudocyclic products that are formed under basic conditions. Pseudocyclic and cyclic trivalent iodonium salts can undergo synthesis, with hydroxy and carboxylic acid group compounds, producing these groups in the products and increasing reactivity in compounds obtained. Some of the pseudocyclic and cyclic diaryliodonium salts obtained have been confirmed with single crystal X-ray crystallography. These positive results lead to further investigation of taking advantage of protecting groups and phenyl boronic acid in the preparation of phenolic iodonium triflate salts. Several desired phenolic iodonium triflate salts were obtained in moderate to good yield and are reported as well.
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    Preparation of Diaryliodonium Salts with Hydroxy and Carboxylic Acid Groups (2021-04-09)
    (2021) Larson, Scott; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    Toxic transition metals are often used in organic synthesis reactions, which poses apotential hazard in their applications, especially medicinally and environmentally. Apotential solution to this problem is to use trivalent iodine in place of toxic transition metalsin synthesis. One class of compounds that could be specifically useful in toxic transitionmetal replacement is pseudo-cyclic iodonium triflate salts. This project focuses onproducing the best method and scope for the preparation of diaryliodonium salts fromiodosobenzoic acid-triflate (IBA-OTf) and (3-acetoxyphenyl)-3-iodanediyl diacetatecompounds. These compounds could be used in oxidation reactions, replacing commonlyused transition metals and would be safer and more environmentally friendly reagents. Thepreparing of these diaryliodonium salts can be optimized since there are various possiblesynthesis conditions available. It was important to find optimal methods for preparingdiaryliodonium salts avoiding the use of toxic transition metals. First, benzene was investigated to test which starting material was best suited for thesynthesis of diaryliodonium salts. Then several other precursors were tested in the reactionto see if it could form trivalent iodine, especially compounds less carcinogenic thanbenzene. After working with other compounds, optimization of the most suitable reactionwas conducted. Dichloromethane and acetonitrile were found to be the most suitable solvents for thesynthesis of diaryliodonium salts from the starting materials mentioned. It was also foundthat triflic acid (TfOH) was necessary for cleaving or breaking bonds in the synthesis ofdiaryliodonium salts. The products were found to be completely soluble in acetonitrile,which was useful for transferring in the reaction. There were several compounds that wereable to react to form diaryliodonium salts with high yield. In conclusion, the hypothesis wassupported with the successful optimization of diaryliodonium salts syntheses from IBA-OTfand (3-acetoxyphenyl)-?3-iodanediyl diacetate compounds.