Mild and regioselective iodination of electron-rich aromatics with N-iodosuccinimide and catalytic trifluoroacetic acid
Anne-Sophie Castanet, Françoise Colobert* and Pierre-Emmanuel Broutin
*Laboratoire de stéréochimie associé au CNRS, URA 7509, Université Louis
Pasteur, ECPM, 25 rue Becquerel, 67087, Strasbourg Cedex 2, France, Email:
fcolober
chimie.u-strasbg.fr
A.-S. Castanet, F. Colobert, P.-E. Broutin, Tetrahedron Lett., 2002, 43, 5047-5048.
DOI: 10.1016/S0040-4039(02)01010-9
Abstract
Various methoxy- or methyl-substituted aromatic compounds were regioselectively iodinated with N-iodosuccinimide and a catalytic amount of trifluoroacetic acid with excellent yields under mild conditions and short reaction times.
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Details
The document discusses a study on the mild and regioselective iodination of electron-rich aromatic compounds using N-iodosuccinimide (NIS) and catalytic trifluoroacetic acid (CF3COOH). The research, conducted by Anne-Sophie Castanet, Françoise Colobert, and Pierre-Emmanuel Broutin at the Université Louis Pasteur, demonstrates that this method provides excellent yields under mild conditions and short reaction times. The iodination process is particularly effective for aromatic compounds substituted with methoxy or methyl groups, achieving high yields at room temperature within minutes to a few hours. The study highlights the importance of iodoarenes in organic synthesis due to their ease of functionalization through metal-catalyzed cross-coupling reactions and their potential as intermediates and bioactive materials. The authors note that previous methods often required hazardous reagents or high temperatures, whereas their approach using NIS and catalytic CF3COOH is more efficient and safer. The active species for the iodination is likely the in situ formed iodine trifluoroacetate, which acts as a highly reactive electrophile. The research was financially supported by Rhodia Chimie and includes references to various related studies in the field.
Key Words
aromatic iodination, N-iodosuccinimide, trifluoroacetic acid
ID: J72-Y2002-1760
