穏やかなヨウ素化・酸化試薬 (Barluenga試薬)

ビス(ピリジン)ヨードニウムテトラフルオロボラートは，Barluengaらによって開発されたヨウ素化・酸化試薬です。温和な条件下で，種々のアルケン類や芳香族化合物に位置選択的にヨウ素を導入することができます。また酸化試薬としても有用であり，種々のアルコール類から対応するケトン，アルデヒド類への変換も報告されています。

[1] “Transferring iodine: more than a simple functional group exchange in organic synthesis”

J. Barluenga, Pure Appl. Chem. 1999, 71, 431. DOI: 10.1351/pac199971030431

[2] “α-Iodination of enaminones with bis(pyridine)iodonium(I) tetrafluoroborate”

P. J. Campos, J. Arranz, M. A. Rodríguez, Tetrahedron Lett. 1997, 38, 8397. DOI: 10.1016/S0040-4039(97)10231-3

Primary, secondary and tertiary enaminones react with bis(pyridine)iodonium(I) tetrafluoroborate in methylene chloride at room temperature to give α-iodo enaminones in almost quantitative yields. The reported reaction is the first known example of direct iodination of tertiary enaminones.

[3] “Bis(pyridine)iodonium Tetrafluoroborate (IPy2BF4): A Versatile Oxidizing Reagent”

J. Barluenga, F. González-Bobes, M. C. Murguía, S. R. Ananthoju, J. M. González, Chem. Eur. J. 2004, 10, 4206. DOI: 10.1002/chem.200400136

A multitalented reagent for several transformations (see scheme), IPy2BF4 can act as a versatile oxidizing reagent, selectively affording ω-iodinated carbonyl derivatives, α,ω-dialdehydes, ketones, aldehydes or esters, depending on the structures of the starting materials and the experimental conditions.