1214751-26-4Relevant academic research and scientific papers
C≡C triple bond activation by heterocyclic aluminum phosphinides
Westenberg, Hauke,Chris Slootweg,Hepp, Alexander,Koesters, Jutta,Roters, Steffi,Ehlers, Andreas W.,Lammertsma, Koop,Uhl, Werner
, p. 1323 - 1330 (2010)
Treatment, of aryl-di(tert-butylethynyl)phosphines Aryl-P(C≡C- CMe3)2 [Aryl = C6H5 (4) 2,4,6-Me3C6H2 (5)] with dialkylaluminum hydrides, R2Al-H (R = CMe3, CH2CMe 3), afforded heterocyclic, zwitterionic compounds 6-9 by hydroalumination and release of the corresponding dimeric tert-butylethynyl- dialkylaluminum derivatives, [R2Al-C≡C-CMe3] 2 (10 and 11). The molecular structures of 6-8 reveal a P 2C2Al ring with a tetracoordinated aluminum atom, two exocyclic C=C double bonds, a tricoordinated phosphorus atom, and a phosphonium cation carrying an aryl and an alkynyl group. The C≡C triple bond of 7 was inserted into the Al-P bonds of the heterocycles upon warming to give the bicyclic compound 13. A similar compound (12) was directly formed when the bisalkyne 4 was treated with dineopentylaluminum hydride. Their molecular structures show the annulated four- (AlC2P) and five-membered heterocycles (P2C3) to contain three different C=C double bonds. The sterically most shielded monocyclic compound (8; Aryl = 2,4,5-Me 3C6H2; R = CMe3) decomposed upon warming. DFT calculations were used to examine these reactions.
