Synthesis of Diverse Aryliodine(III) Reagents by Anodic Oxidation^†

Abstract

An anodic oxidation enabled efficient synthesis of hypervalent iodine(III) reagents from aryl iodides is demonstrated. Under mild electrochemical conditions, a range of aryliodine(III) reagents including iodosylarenes, (difunctionaliodo)arenes, benziodoxoles and diaryliodonium salts can be efficiently synthesized and derivatized in good to excellent yields with high selectivity. As only electrons serve as the oxidation reagents, this method offers a more straightforward and sustainable manner avoiding the use of expensive or hazardous chemical oxidants.

Scalable electrochemical synthesis of diaryliodonium salts

“…A very recent report on the electrochemical synthesis of aryliodine(III) reagents including some diaryliodonium salts emerged during the final preparation of this work. 17 affected by the nature of the anionic part of the molecule. Previously published electrochemical methods for their preparation utilised H 2 SO 4 /AcOH/Ac 2 O as the reaction medium but these suffered from low yields and side product formation.…”

Electrochemical Radical Silyl‐Oxygenation of Activated Alkenes

“…Very recently, Lin and co‐workers developed a more efficient electro‐reductive protocol to access silyl radical by activating chlorosilane at deeply reducing potentials and demonstrated its use in C−Si bond forming reactions (Scheme 1 b, lower left) [10] . With the continued interest in organosilicon chemistry [11] and electrosynthesis, [12] we questioned whether electrochemical oxidative radical 1,2‐silylfunctionalization of alkenes could be established. We proposed that, if a silyl radical could be generated by anodic oxidation of a hydrosilane (Scheme 1 b, right), it could be trapped by an alkene to give a α‐silyl alkyl radical.…”

Recent Updates on Electrogenerated Hypervalent Iodine Derivatives and Their Applications as Mediators in Organic Electrosynthesis

“…Very recently (2021), He and others ( Zu et al, 2021 ) have presented a comprehensive investigation on the usage of anodic oxidation of aryl iodides in the synthesis of diverse hypervalent iodine compounds ( Scheme 1C ). They provided a sustainable and broadly applicable approach for accessing four types of aryl iodide(III) reagents: iodosylarenes, (difunctionaliodo)arenes, benziodoxoles, and diaryliodonium salts, among others.…”

“…Based on their method for the electrochemical synthesis of aryl iodide(III) reagents mentioned above, He and his co-workers further developed two oxidative transformations, trifluoro-ethoxylactonization, and tosyloxylation, enabled by anodically generated iodine (III) intermediate 1a ( Zu et al, 2021 ). The two reactions were both conducted in an undivided cell equipped with platinum electrodes under a constant current of 5 mA, using n-Bu 4 NBF 4 as the electrolyte and TFE as the solvent ( Schemes 2J,K ).…”