4,4′-Bis(dichloroiodo)biphenyl and 3-(Dichloroiodo)benzoic Acid: New Recyclable Hypervalent Iodine Reagents for Vicinal Halomethoxylation of Unsaturated Compounds

Abstract

4,4¢-Bis(dichloroiodo)biphenyl and 3-(dichloroiodo)benzoic acid are convenient recyclable hypervalent iodine reagents for vicinal chloromethoxylation or iodomethoxylation of unsaturated compounds. The reactivity of these reagents in the reaction of vicinal halomethoxylation is generally similar to dichloroiodobenzene and the advantage of their use is that the reduced forms of these reagents can be easily separated from the reaction mixture and reused for the regeneration of the reagents.

Chemistry of Polyvalent Iodine

“…This method can be applied to the large scale (20–25 kg) preparation of PhICl 2 by the reaction of iodobenzene with chlorine at −3 to +4 °C in dichloromethane 210. The direct chlorination of iodoarenes 75 and 77 has recently been used for the preparation of 4,4′-bis(dichloroiodo)biphenyl 76 and 3-(dichloroiodo)benzoic acid 78 (Scheme 22), which are convenient recyclable hypervalent iodine reagents 211…”

“…Likewise, the reaction of 4,4′-bis(dichloroiodo)biphenyl 76 with styrene derivatives 81 in methanol affords exclusively the products of electrophilic chloromethoxylation 82 (Scheme 24). 211…”

Hypervalent Iodine Chemistry in Synthesis: Scope and New Directions

“…This enantioselectivity is slightly lower than that attained when using N ‐chlorosuccinimide as the chlorinating agent in similar reactions 65. The recently reported biphenyl derivative 35 might be advantageous in such reactions 66. Although the stereoselectivities are only moderate, the transfer of ligands X from the great number of known compounds of the type ArIX 2 to enolizable substrates by using a stereoselective catalytic protocol is very promising.…”

Polyvalent iodine in organic chemistry: Recent developments, 2002–2005

“…Recent recyclable hypervalent iodine reagents for vicinal halomethoxylation of unsaturated compounds are 4,4 -bis(dichloroiodo)biphenyl and 3-(dichloroiodo)benzoic acid [57]. Sometimes such reactions are accompanied by oxidizing rearrangements [58] (Schemes 21 and 22).…”