Aluminum(III) complexes containing O,O chelating ligand

The stoichiometric reactions of trimethylaluminum with 2,6‐(MeOCH 2 ) 2 C 6 H 3 OH (LH) revealed compounds L 3 Al ( 1 ) and L 2 AlMe ( 2 ). On the other hand reaction of 1 equiv. of LH with trimethylaluminum did not lead to the formation of complex LAlMe 2 ( 3 ), rather 2 together with Me 3 Al were observed as a result of a disproportionation of 3 . Compounds 1 and 2 were characterized by elemental analysis, 1 H and 13 C NMR spectroscopy and in the case of 1 by X‐ray diffraction. Derivative 2 underwent transmetalation with Ph 3 SnOH, giving LSnPh 3 ( 4 ) as the result of a migration of ligand L from the aluminum to the tin atom. The identity of 4 was established by elemental analysis, 1 H, 13 C and 119 Sn NMR spectroscopy and 1 H, 119 Sn HMBC experiments. The system 2 and B(C 6 F 5 ) 3 in a 1:1 molar ratio was shown to be active in the polymerization of propylene oxide and ε‐caprolactone. Copyright © 2007 John Wiley & Sons, Ltd.