Reactions Of Iodonium Salts Research Articles

ChemInform Abstract: Chromium(II)-Mediated Reactions of Iodonium Tetrafluoroborates with Aldehydes: Umpolung of Reactivity of Diaryl-, Alkenyl(aryl)-, and Alkynyl(aryl)iodonium Tetrafluoroborates.

The method described herein allows us, for the first time, to perform umpolung of reactivity of diaryl-, alkenyl(aryl)-, and alkynyl(aryl)iodonium tetrafluoroborates. The method involves generation of organochromium(III) species via reaction of iodonium salts with anhydrous chromium dichloride, followed by their nucleophilic addition to aldehydes to yield alcohols. In contrast to the reaction of aryl and alkenyl halides with chromium dichloride, these iodonium salts are so active that organochromium(III) could be generated without using a nickel catalyst. Substituent effects of unsymmetrically substituted diaryliodonium salts on the product profiles are in good agreement with the reported mode of decomposition of the intermediate unsymmetrical diaryliodanyl radicals. Alkenyl(mesityl)iodonium tetrafluoroborates undergo exclusive alkenylation of aldehydes with no signs of the formation of an arylation product.

Chromium(II)-Mediated Reactions of Iodonium Tetrafluoroborates with Aldehydes: Umpolung of Reactivity of Diaryl-, Alkenyl(aryl)-, and Alkynyl(aryl)iodonium Tetrafluoroborates.

The method described herein allows us, for the first time, to perform umpolung of reactivity of diaryl-, alkenyl(aryl)-, and alkynyl(aryl)iodonium tetrafluoroborates. The method involves generation of organochromium(III) species via reaction of iodonium salts with anhydrous chromium dichloride, followed by their nucleophilic addition to aldehydes to yield alcohols. In contrast to the reaction of aryl and alkenyl halides with chromium dichloride, these iodonium salts are so active that organochromium(III) could be generated without using a nickel catalyst. Substituent effects of unsymmetrically substituted diaryliodonium salts on the product profiles are in good agreement with the reported mode of decomposition of the intermediate unsymmetrical diaryliodanyl radicals. Alkenyl(mesityl)iodonium tetrafluoroborates undergo exclusive alkenylation of aldehydes with no signs of the formation of an arylation product.

Application of spin trapping in the study of the electrochemical and photochemical synthesis of phenylated C60 derivatives with iodonium salts

AbstractA spin trap technique was used to investigate the fullerene phenylation both electrochemically and photochemically using the reactions of iodonium salts. Phenyl radicals, produced in the cathodic reduction as well as during the photolysis of iodonium salts, were trapped by nitroso‐tert‐butane (BuNO) and nitrosodurene (ND) spin traps. However, no phenyl radicals could be detected by ESR during the irradiation of diphenyliodonium iodide, or during its electrochemical reduction, in the presence of C60. This indicates that prior trapping of phenyl radicals to d̊BuNO and ND spin trap agents, their trapping by fullerenes occurred. The radical mechanism of electrochemical and photochemical phenylation of C60 using iodonium salts are discussed and these two phenylation techniques are compared.