Silver tetrakis(hexafluoroisopropoxy)aluminate as hexafluoroisopropyl transfer reagent for the chlorine/hexafluoroisopropyl exchange in imino phosphanes

Treating 1,3-dichloro-2,4-bis[tris(trimethylsilyl)silyl]-cyclo-diphosphadiazane, [HypNPCl]2 ((Me3Si)3Si = Hyp), or N-(2,4,6-tri-tert-butylphenyl)imino(chloro)phosphane, Mes∗–NP–Cl (Mes∗ = 2,4,6-tri-tert-butylphenyl), with Ag[Al(OCH(CF3)2)4] leads to the abstraction of [OCH(CF3)2]− from the counter ion [Al(OCH(CF3)2)4]− in a formal Lewis acid/Lewis base reaction. The final products Hyp2N2P2(Cl)(OCH(CF3)2), Mes∗–NP–OCH(CF3)2 and the dimeric Lewis acid [Al(OCH(CF3)2)3]2 have been characterized by means of X-ray analysis.

Highly reactive hypersilylated cyclo-diphosphadiazenium [Hyp2N2P2Cl]+ and supermesityl substituted iminophosphenium [Mes∗–NP]+ cations, which are capable of abstracting [OCH(CF3)2]− from the [Al(OCH(CF3)2)4]− counter ion in formal Lewis acid/Lewis base reactions are discussed. By this approach the hitherto unknown Mes∗–NP–OCH(CF3)2 and Hyp2N2P2(Cl)OCH(CF3)2 as well as the dimer of the free Lewis acid [Al(OCH(CF3)2)3]2 have been obtained and fully characterized.Figure optionsDownload as PowerPoint slide