Si–O-Bindungsspaltung in einem Siloxamin durch Aluminiumhydrid

Si–O Bond Fission in a Siloxamine by Aluminium Hydride When the alkoxyaminosilane tBu-OtBuN(H)]SiMe₂ ( 1 ) reacts with aluminium hydride the expected cyclic alkoxyaluminosilane tBuO(tBuN)(AlH₂)SiMe₂ ( 2 ) is not obtained. Instead 1 reacts directly with two equivalents of aluminiumhydride to the alkoxyaminodialane 3 , (tBuO)(AlH₂)N(SiMe₂H)tBu](AlH₂). The compound 3 is characterized by spectroscopic methods and by a single crystal X-ray diffraction analysis: the molecule has a four-membered OAl₂N cycle (Al–O 1.817(2) Å, Al–N 1.970(1) Å) as central unit. On the oxygen and nitrogen atom a tertbutyl or a tert-butyl and HMe₂Si group are attached, while the aluminium atoms have exclusively hydrogen as further ligands. The Si–O bond in the starting compound 1 has thus been cleaved, the oxygen atom being coordinated by aluminium and the silicon atom by hydrogen.