Isolable Phospha- and Arsaalumenes

Abstract

The combination of (AlCp*)₄, a source of monomeric :AlCp* at elevated temperatures, with ^DipTerPnPMe₃ (Pn = P, As), so-called pnicta-Wittig reagents, at 80 °C cleanly gives the pnictaalumenes ^DipTerPnAlCp* with polarized Pn-Al double bonds and intramolecular stabilization through interactions of Al with a flanking aryl group of the terphenyl substituent on Pn. In contrast, using ^MesTerPPMe₃, the reaction with 2 equiv of :AlCp^3t or :AlCp* afforded the three-membered 2π-aromatic ring systems ^MesTerP(AlCp^<i>x</i>)₂ (<i>x</i> = 3t, *).