Resolution of Planar Chiral Cationic (η6-Arene)tricarbonylmanganese Complexes

This contribution describes the first resolution of cationic (η6-arene)Mn(CO)3 complexes through addition of d-(+)-camphor enolate, isomerization of the stereogenic center, and separation and recrystallization of the corresponding η5 diastereoisomers followed by rearomatization and elimination of the chiral auxiliary. This general unprecedented chiral nucleophile addition/elimination (η6−η5)/(η5−η6) “round trip” sequence uses a cheap, commercialy available chiral nucleophile. As it is compatible with the presence of halide and alkoxy groups, a huge number of applications are envisaged. Some of them, such as the synthesis of enantiopure substituted cyclohexenones, are reported in the present work.