Catalytic asymmetric synthesis of optically active amines and their derivatives

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For the development of the asymmetric synthesis of optically active amines and their derivatives, we examined the enanioselective addition of trimethylsilyl cyanide to a variety of N-substituted imines. At first, we investigated the reaction catalyzed by chiral Schiff base-titanium alkoxide complexes which was very effective for enantioselective trimethylsilylcyanation of aldehydes. We found that by using chiral titanium complexes, high chemical yield was attained, but only unsatisfied optical yield (20% ee) was obtained. The chiral titanium complex bearing chiral binaphthol derivatives was also found to give only low optical yield. Then we examined the reaction catalyzed by cationic chiral BINAP- palladium complex. By using complex of in-situ preparation and isolated one, low optical yield was obtained in both cases though chemical yield was high. Based on the above results we changed the strategy for the synthesis of optically active amines, that is, catalytic asymmetric allylic amination catalyzed by palladium complexes. We have succeeded in the synthesis of novel palladium catalyst having P, N-bidentate ligands. These new catalyst was found to have high catalytic activity and enantioselectivity in catalytic allylic alkylation. The optical yields of the allylic alkylation products were over 80% ee. At present, the asymmetric amination is being examined.