Cyclic diaryliodonium salts: applications and overview

Recent Progress in Synthetic Applications of Hypervalent Iodine(III) Reagents

Hypervalent iodine(III) compounds have found wide application in modern organic chemistry as environmentally friendly reagents and catalysts. Hypervalent iodine reagents are commonly used in synthetically important halogenations, oxidations, aminations, heterocyclizations, and various oxidative functionalizations of organic substrates. Iodonium salts are important arylating reagents, while iodonium ylides and imides are excellent carbene and nitrene precursors. Various derivatives of benziodoxoles, such as azidobenziodoxoles, trifluoromethylbenziodoxoles, alkynylbenziodoxoles, and alkenylbenziodoxoles have found wide application as group transfer reagents in the presence of transition metal catalysts, under metal-free conditions, or using photocatalysts under photoirradiation conditions. Development of hypervalent iodine catalytic systems and discovery of highly enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important recent achievement in the field of hypervalent iodine chemistry. Chemical transformations promoted by hypervalent iodine in many cases are unique and cannot be performed by using any other common, non-iodine-based reagent. This review covers literature published mainly in the last 7-8 years, between 2016 and 2024.

Palladium-Catalyzed Triple Suzuki-Miyaura Reactions Using Cyclic (Vinyl Triflate)iodonium Salts

By using cyclic (vinyl triflate)iodonium salts, a novel triple Suzuki-Miyaura reaction was accomplished for the synthesis of polyaromatic ethylene derivatives in the presence of palladium catalysts. The reaction exhibits extensive compatibility with a wide range of readily available arylboronic acids, giving triaryl-substituted ethylenes in good yields.

I2/DMSO-mediated oxidative C-C and C-heteroatom bond formation: a sustainable approach to chemical synthesis

The I2/DMSO pair has emerged as a versatile, efficient, practical, and eco-friendly catalyst system, playing a significant role as a mild oxidative system, and thus employed as a good alternative to metal catalysts in synthetic chemistry. Presently, I2/DMSO is a thriving catalytic system that is used in preparing C-C and C-X (X = O/S/N/Se/Cl/Br) bonds, resulting in the formation of various bioactive molecules. Many processes utilize this system, including in situ glyoxal synthesis by diverse sp, sp2, and sp3 functionalities via iodination and subsequent Kornblum oxidation. Focusing on oxidation processes, this study examines the synergistic effect of dimethyl sulfoxide (DMSO) and molecular iodine in improving synthetic techniques. We provide a comprehensive overview of the research progress on the I2/DMSO catalytic system for the formation of C-C and C-heteroatom bonds from 2018 to the present. Additionally, the future prospects of this research field are discussed.

Aryl sulfonyl fluoride synthesis via organophotocatalytic fluorosulfonylation of diaryliodonium salts

A mild and efficient synthesis of various aryl sulfonyl fluorides from diaryliodonium salts under organophotocatalysis via a radical sulfur dioxide insertion and fluorination strategy is presented. Diaryliodonium salts are used as aryl radical precursors, the 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) adduct (DABSO) as a sulfonyl source and cheap KHF2 as a desirable fluorine source, respectively. Notably, the electronic properties of substituents on the aromatic rings in diaryliodonium salts have a significant influence on the reaction yields.