The Study Of Aryliodonium Salts In Synthetic Methodology

Diaryliodonium salts are air- and moisture-stable compounds. They are efficient alternatives to expensive organometallic catalysts in some reactions. Linear diaryliodonium salts possess T-shape, and iodobenzene as byproduct is a good leaving group. Which makes them as good arylating reagents. This dissertation mainly focuses on the synthetic applications of trivalent aryliodonium salt:(i) Studies on the trivalent aryliodonium salts as Lewis acid catalysts in Mannich reactions. (ii) Studies on the potassium tert-butoxide mediated a-arylation of N-acetylindolin-3-ones with diaryliodonium salts under trasition-metal free conditions. (iii) Studies on the palladium catalyzed double Suzuki-Miyaura reactions between cyclic dibenziodoniums and arylboronic acids.Firstly, diaryliodonium salts as highly active and versatile Lewis acid catalysts for the direct three component Mannich reaction under solvent free conditions have been investigated. The Mannich products were isolated in good to excellent yields in a very clean manner. Additionally, the catalyst could be recycled without significant loss of its catalytic activity.Secondly, the potassium tert-butoxide mediated a-arylations of N-acetylindolin-3-ones with diaryliodonium salts under trasition-metal free conditions have been developed. The procedure was tolerant of a variety of substituents, and various mono-arylated indolinone derivatives can be readily obtained in 24-70% yields with this method. Moreover, the alkylation of mono-arylated indolinone derivatives proceeds well and affords the corresponding 2,2-disubstiuted products in good yields.Thirdly, palladium-catalyzed double Suzuki-Miyaura couplings between cyclic dibenziodoniums and arylboronic acids have been developed. As such, a wide range of ortho-tetraaryls were synthesized in good to excellent yields of 22-94%. Furthermore, tetraphenylene was prepared in 21% isolated yield with 2,2'-biphenyldiboronic acid by using this method.