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

Hypervalent iodine compounds have found broad application in modern organic chemistry as reagents and catalysts. Cyclic hypervalent iodine reagents based on the benziodoxole heterocyclic system have higher stability compared to their acyclic analogues, which makes possible the preparation and safe handling of the reagents with special ligands such as azido, cyano, and trifluoromethyl groups. Numerous iodine-substituted benziodoxole derivatives have been prepared and utilized as reagents for transfer of the substituent on hypervalent iodine to organic substrate. Reactions of these reagents with organic substrates can be performed under metal-free conditions, in the presence of transition metal catalysts, or using photocatalysts under photoirradiation conditions. In this review, we focus on the most recent synthetic applications of cyclic hypervalent iodine(III) reagents with the following ligands: N-3, NHR, CN, CF3, SCF3, OR, OAc, ONO2, and C(=N-2)CO2R. The review covers literature published mainly in the last 5 years.

Automated summary

Hypervalent iodine compounds, particularly those based on the benziodoxole heterocyclic system, are widely used as reagents and catalysts in modern organic chemistry. These cyclic hypervalent iodine reagents exhibit higher stability compared to their acyclic analogues, allowing for the safe handling and preparation of reagents with special ligands such as azido, cyano, and trifluoromethyl groups. They have been utilized for the transfer of substituents on hypervalent iodine to organic substrates under various reaction conditions. This review focuses on the recent synthetic applications of cyclic hypervalent iodine(III) reagents with different ligands, including N-3, NHR, CN, CF3, SCF3, OR, OAc, ONO2, and C(=N-2)CO2R, mainly in the past 5 years.