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Abstract (English)

P,N-chelating systems are widely used ligands in catalytic reactions. Oxazoline containing systems such as PHOX-ligands are very important. In this work atropisomeric P,N-containing ligands based on an imidazol backbone are presented. BIMNAP (Sₐ-1), one of the first axial chiral P,N-ligand with imidazole backbone, was synthesised by separating the enantiomers by diastereoselective resolution. BIMNAP catalysed the asymmetric allylic substitution of diphenylallylacetate (100) with dimethylmalonate with 80 % yield and 94 % ee. Furthermore it was tested in the catalytic hydroboration of styrene and resulted in 50% ee in this reaction. Some other atropisomeric imidazole containing ligands with different substituents and a tetrazole containing ligand were easily produced but could not be separated into their enantiomers.

Besides, based on molecules of the chiral pool, new enantiomerically pure P,N-systems were designed. On a route adopted from Casey and Pfaltz PHIM related products were synthesised from aminoalkohols and 2-benzyloxy-naphthaline-1-carboxylic acid chloride, but they could not be purified to test them in catalysis. From L-proline and o-phenylendiamine diphenylphosphinamine- and alkylphosphinamiditesystems (Me. Et, i-Pr) were generated. These ligands catalysed the above mentioned asymmetric allylic substitution with 80 % yield and 74 % ee. The asymmetric hydroboration of styrene was catalysed with an enantiomeric excess up to 50 % ee.