QUANTUM-CHEMICAL MODELING OF CHIRAL CATALYSIS .14. ON THE COORDINATION OF CARBONYL-COMPOUNDS TO DIAZALUMINOLIDINE, OXAZALUMINOLIDINE AND DIOXALUMINOLIDINE OF POTENTIAL USE AS CHIRAL CONTROLLERS IN ORGANIC SYNTHETIC CHEMISTRY

Conformers of 4-coordinate adducts of carbonyl compounds and diaza-, o xaza- and dioxaluminolidines were investigated by means of ab initio M O methods (RHF). Formaldehyde was used as a model of carbonyl compound s. Relative stabilities of the conformers indicate formation of syn ad ducts of carbonyl compounds and aluminolidines (C-c=o and aluminolidin e ring syn about the Al-O-c=o bond) to be favoured over that of the co rresponding anti ones (all synlanti ratios higher than 99:1, 6-31G//6- 31G). The energetic preference for the formation of syn adducts of oxa zaaluminolidines was about twice as high as that of diaza- or dioxalum inolidines of which the synlanti selectivities were found to be practi cally equal.