Oxidation of sulfides using recyclable pseudocyclic benziodoxole triflate

Abstract

A new pseudocyclic hypervalent iodine reagent, benziodoxole triflate (IBA-OTf, a complex of 2-iodosylbenzoic acid with trifluoromethanesulfonic acid), can be used as an efficient oxidant for selective oxidation of various organic sulfides to sulfoxides. This oxidation proceeds under mild condition to afford the corresponding sulfoxides in moderate to good yields without overoxidation. The reduced form of the hypervalent iodine reagent, 2-iodobenzoic acid, can be easily recovered from the reaction mixture in good yields by a simple acidbase liquid-liquid biphasic protocol.

Organohypervalent heterocycles

“…530 Further, the preparation, structure, and reactions of 2-iodosylbenzoic acid triflate (IBA-OTf, 179) were recently investigated by Zhdankin and coworkers. 531,532 The synthetic applications of IBA-OTf (179) as a catalyst in oxidative heteroannulations 533,534 and efficient precursor to novel sulfoximidoyl-substituted hypervalent iodine 535 have been recently investigated. Besides, the X-ray crystal structures and the reactions of certain other new pseudocyclic benziodoxole tosylates 180, analogs of benziodoxole triflate, have also been invetsigated.…”

Recyclable Hypervalent Iodine Reagents in Modern Organic Synthesis

“…76 Scheme 24 Reaction of 100 with various organic substrates Treatment of various sulfides 141 with 100 at room temperature for 10 minutes resulted in controlled oxidation to give the corresponding sulfoxides 142 in 56-100% yield (Scheme 25), except in the case of 2-(phenylthio)ethanol, which was oxidized to 2-(phenylsulfinyl)ethanol under similar conditions in 24% yield. 77…”

Preparation, Structure, and Reactivity of Pseudocyclic β‐Trifluorosulfonyloxy Vinylbenziodoxolone Derivatives

“…In a previous experiment, we have found that IBA‐TfOH 6 and trimethylsilyl‐substituted acetylene in the presence of trifluoromethanesulfonic acid (TfOH) afforded pseudocyclic β‐trifluorosulfonyloxy vinylbenziodoxolone 7 a in 62% (Scheme 1). [5] We have previously reported that IBA‐TfOH 6 can be conveniently generated by mixing IBA ( 5 a ) and TfOH [5,9] . In order to obtain the desired pseudocyclic product, we developed a one‐pot reaction method that combines the two reactions: 1) in‐situ generation of IBA‐TfOH 6 from IBA 5 a and TfOH, and 2) electrophilic addition of the generated 6 to alkyne (Table 1).…”

“…[5] We have previously reported that IBA-TfOH 6 can be conveniently generated by mixing IBA (5 a) and TfOH. [5,9] In order to obtain the desired pseudocyclic product, we developed a one-pot reaction method that combines the two reactions: 1) in-situ generation of IBA-TfOH 6 from IBA 5 a and TfOH, and 2) electrophilic addition of the generated 6 to alkyne (Table 1). In the initial experiment, the importance of trimethylsilyl (TMS) group was investigated (entries 1-3).…”