Synthese und Charakterisierung chiraler Organogallium- und -aluminiumalkoholate mit intramolekularer Stickstoffstabilisierung. Röntgenstrukturanalyse von Dimethylgallium-(S)-2-dimethylamino-3-methyl-1-butanolat, Dimethylgallium-(S)-2-dimethylamino-3-pheny

The reactions of trimethylgallium and trimethylaluminium with optically active alcohols yield [Me2GaOCH2CHRNMe2]2 [R=Me (S) 6, iPr (S) 7, iBu (S) 8, Bz (S) 9, Et (R:S>90:10) 10] and [Me2AlOCH2CHRNMe2]2 [R=iBu (S) 11, Et (R:S>90:10) 12], respectively. The compounds have been characterized by 1H-,13C-NMR and mass spectroscopy. They undergo a dynamic process with respect to the dissociation and association of the GaN or AlN dative bond resulting in equilibria between four- and five-coordinate metal atoms. The structures of 7, 9 and 10 were determined by single crystal X-ray diffraction. The molecules exist as dimers containing a M2O2 four-membered ring. 6–11 exclusively consist of dimers with enantiomerically equal ligands; 12, on the contrary contains diastereomeric dimers featuring different NMR spectra.