α-Aryliodonio Diazo Compounds: SN Reactions at the α-C Atom as a Novel Reaction Type for Diazo Compounds

✍ Scribed by Prof. Dr. Robert Weiss; Dipl.-Chem. Jörg Seubert; Dr. Frank Hampel

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 259 KB
• Volume: 33
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.199419521

✦ Synopsis

Three fundamental reaction types account for the versatility of diazo compounds as reagents in organic chemistry: S, reactions at the a-C atom, carbene generation, and cycloadditions. Although this class of compounds and their reactions have been known for well over 100 years,"] no examples of an S, reaction at the a-C atom with retention of the diazo function have been reported."' This type of reaction would require functionalization of the r-C atom of the diazo compound with a potent nucleofuge. Since the aryliodonio function is such a nucleof~ge,[~~ we thought that the previously unknown x-aryliodonio diazo compounds would be suitable for the realization of this type of reaction. As we report here. this proposed type of reaction succeeded.

The title compounds, the first r-aryliodonio diazo compounds, are easily accessible via bis(onio)-substituted aryliodine(II1) salts such as 1. which we described r e ~e n t 1 y . I ~~ Compound 1 reacted rapidly at room temperature with tert-butyl diazoacetate (3) and ethyl diazoacetate (4) to give the corresponding x-aryliodonio diazo compounds 5 and 6, respectively (path A, Scheme 1).