One-step synthesis of chiral azamacrocycles via palladium-catalyzed enantioselective amination of 1,5-dichloroanthraquinone and 1,5- dichloroanthracene

Asymmetric amination of 1,5-dichloroanthraquinone and 1,5-dichloroanthracene with di- and trioxadiamines catalyzed by palladium complexes with various chiral phosphine ligands gave chiral macrocycles with ee values of up to 60%. The dependence of the chemical yields and enantiomeric excess on the nature of the starting compounds and the phosphine ligands employed was demonstrated. An unexpected spontaneous resolution upon crystallization of the macrocycle comprising anthraquinone and dioxadiamine moieties was observed while in the case of the macrocycle with a trioxadiamine linker racemic monocrystals were obtained. Crystallization of the enantiomerically enriched mixtures afforded chiral macrocycles with 88-99% ee.