Reactions of β-diketiminatoaluminum hydrides with tert-butyl hydrogenperoxide – Facile formation of dialuminoxanes containing Al–O–Al groups
摘要:
Treatment of diphenyl-beta-diketiminatoaluminum dihydride, LAlH(2) [1, L = {H(5)C(6)-N = C(Me)}(2)CH] with neo-pentyl- or trimethylsilylmethyllithium afforded the corresponding alkylderivatives LAlH(R) [R = CH(2)-SiMe(3) (2), CH(2)-CMe(3) (3)] by the precipitation of lithium hydride. Deprotonation of a methyl group instead of salt elimination occurred by the similar reaction of the more basic alkyllithium compound LiC (SiMe(3))(3). The reactions of the hydrides 1-3 with tert-butyl hydrogenperoxide did not yield the expected peroxo derivatives, instead the dialuminoxanes LAl(R)-O-Al(R)L [R = OCMe(3) (5), CH(2)SiMe(3) (6), CH(2)CMe(3) (7)] were isolated in high yields. Their Al-O-Al bridges deviated from linearity and had Al-O-Al bond angles of about 155 degrees on average. (C) 2008 Elsevier B.V. All rights reserved.