Abstract
Isoflavones are synthesized in an one-pot reaction by treating
the hypervalent iodine(III) reagent, [hydroxy(tosyloxy)iodo]benzene
(HTIB, Koser’s reagent) with 2′-benzoyloxychalcones in
MeOH. A combined use of (diacetoxyiodo)benzene (DIB)/p- toluenesulfonic acid (TsOH) is also
effective for the same purpose. As an extension of these monomeric
reagents, polymer-supported DIB {PSDIB, poly[4-(diacetoxy)iodo]styrene} with
TsOH works also well. The merits of the latter are the ease of separation
of isoflavones from the reaction mixture, no liberation
of PhI, and reuse of the reagent.
Key words
chalcones - isoflavones - protecting groups - hypervalent iodine - oxidative rearrangements
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