Formation of a [4.3.0]-bicyclic aluminum-phosphorus compound with annulated C3P2 and Al2C2PH heterocycles and a 3c-2e Al-H-Al bond

Uhl W., Roters S., Hepp A.

Abstract

Treatment of the dialkynylphosphine Mes-P(-C≡C-CMe3) 2 (1) with diethylaluminum hydride (2) in an equimolar ratio afforded a mixture of compounds, in which a [3.2.0]-bicyclic compound 3 with annulated four-membered AlC2P and five-membered P2C3 heterocycles could be identified by NMR spectroscopy. Excess of the hydride 2 yielded small quantities of the zwitterionic [4.3.0]-bicyclic compound 4, which formally resulted from the unique insertion of a diethylaluminum hydride molecule into the Al-C(vinyl) bond of the strained four-membered heterocycle of 3. A six-membered ring is formed which contains an Al-H-Al 3c-2e bond. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.