Oxidative Iodination of Deactivated Arenes in Concentrated Sulfuric Acid with I₂/NaIO₄ and KI/NaIO₄ Iodinating Systems [1]

Abstract

Deactivated arenes were mono- or diiodinated with strong electrophilic I⁺ reagents, which were prepared from NaIO₄ and either I₂ or KI in concentrated H₂SO₄ (minimum 95% by weight). In general a small excess of the dark brown iodinating solution was used (1.1/1.5 equivalents, for nitrobenzene two equivalents was required). The iodinations were conducted at 25-30 °C with a reaction time of 1-2 hours using either a ‘direct’ or an ‘inverse’ method of aromatic iodination to give mono- or diiodinated pure products in 31-91% optimized yields.

iodoarenes - deactivated arenes - iodine - potassium iodide - sodium periodate - direct oxidative iodination

References

<A NAME="RZ20305SS-1">1</A>

These results were partly presented at the 8^th International Electronic Conference on Synthetic Organic Chemistry, paper A024, November 1-30, 2004.

<A NAME="RZ20305SS-2A">2a</A> Roedig A. In Houben-Weyl, Methoden der organischen Chemie   Vol. V/4:  Thieme; Stuttgart: 1960.  p.517-678  

<A NAME="RZ20305SS-2B">2b</A> Merkushev EB. Synthesis  1988,  923 

<A NAME="RZ20305SS-2C">2c</A> March J. Advanced Organic Chemistry. Reactions, Mechanisms, and Structure   4th ed.:  Wiley; New York: 1992.  p.501-507  

<A NAME="RZ20305SS-2D">2d</A> March J. Advanced Organic Chemistry. Reactions, Mechanisms, and Structure   4th ed.:  Wiley; New York: 1992.  p.533-534  

<A NAME="RZ20305SS-3A">3a</A> Varvoglis A. The Organic Chemistry of Polycoordinated Iodine   VCH; Weinheim: 1992. 

<A NAME="RZ20305SS-3B">3b</A> Varvoglis A. Hypervalent Iodine in Organic Synthesis   Academic Press; San Diego: 1997. 

<A NAME="RZ20305SS-3C">3c</A> Stang PJ. Zhdankin VV. Chem. Rev.  1996,  96:  1123 

<A NAME="RZ20305SS-3D">3d</A> Zhdankin VV. Stang PJ. Chem. Rev.  2002,  102:  2523 

<A NAME="RZ20305SS-3E">3e</A> Stang PJ. J. Org. Chem.  2003,  68:  2997 

<A NAME="RZ20305SS-3F">3f</A> Hypervalent Iodine Chemistry, Topics in Current Chemistry   Vol. 224:  Wirth T. Springer Verlag; Berlin: 2003. 

<A NAME="RZ20305SS-3G">3g</A> Moriarty RM. J. Org. Chem.  2005,  70:  2893 

<A NAME="RZ20305SS-3H">3h</A> Wirth T. Angew. Chem. Int. Ed.  2005,  44:  3645 

<A NAME="RZ20305SS-4">4</A> Skulski L. Molecules  2000,  5:  1331 

<A NAME="RZ20305SS-5">5</A> Skulski L. Molecules  2003,  8:  45 

<A NAME="RZ20305SS-6">6</A> Eco-friendly oxidative iodinations of various arenes with a urea-hydrogen peroxide adduct (UHP) as the oxidant: Lulinski P. Kryska A. Sosnowski M. Skulski L. Synthesis  2004,  441 

<A NAME="RZ20305SS-7">7</A> Oxidative iodinations of various deactivated arenes in 90% H₂SO₄: Kraszkiewicz L. Sosnowski M. Skulski L. Tetrahedron  2004,  60:  9113 

<A NAME="RZ20305SS-8">8</A> Oxidative iodinations of various arenes with I₂/NaIO₄ or NaIO₃/Ac₂O/AcOH/ H₂SO₄ iodinating systems: Lulinski P. Skulski L. Bull. Chem. Soc. Jpn.  2000,  73:  951 

For NMR spectra of iodinated arenes, see:

<A NAME="RZ20305SS-9A">9a</A> Lulinski P. PhD Thesis   Medical University of Warsaw; Poland: 2002. 

<A NAME="RZ20305SS-9B">9b</A> Sosnowski M. PhD Thesis   Medical University of Warsaw; Poland: 2005. 

<A NAME="RZ20305SS-9C">9c</A> Zielinska A. PhD Thesis   Medical University of Warsaw; Poland: 2005. 

<A NAME="RZ20305SS-10">10</A> Dictionary of Organic Compounds   Buckingham J. Chapman & Hall; London: 1996.  p.6th ed 

<A NAME="RZ20305SS-11">11</A> Langmuir AC. Ber. Dtsch. Chem. Ges.  1895,  28:  90 

4-Fluoro-3-iodobenzaldehyde (its mp not given), a valuable pharmaceutical intermediate, was prepared in high yield (not specified) and selectively by the regioselective iodination of 4-FC₆H₄CHO with NIS in an acid medium (e.g. AcOH and H₂SO₄):

<A NAME="RZ20305SS-12A">12a</A> Wittenberger SJ, Chang S.-J, and Wayne GS. inventors; PCT Int. Appl.  WO 0370678.  ; Chem. Abstr. 2003, 139, 214207

<A NAME="RZ20305SS-12B">12b</A> Wayne GS, Wittenberger SJ, and Chang S.-J. inventors; U.S. Pat. Appl. Publ. US  2003220526.  ; Chem. Abstr. 2004, 140, 4848