Asymmetric Synthesis of Axially Chiral Compound Utilizing Planar Chiral Transition Metal Complexes and Their Development for Dynamic Complexes

Abstract

Axially chiral biaryls and N-aryl indoles are stereoselectively prepared by utilizing planar chiral transition metal complexes. Both enantiomers of axial biaryls and N-aryl indoles could be synthesized starting from an identical enantiomerically pure arene chromium complex. We applied this method to the synthesis of vancomycin A-B ring system and korupensamines. Kinetically controlled biaryl and N-aryl indole transition metal complexes with sp³ heteroatom at the side chain could be converted to thermodynamically stable complexes involving the inversion or transfer of planar chirality. These results indicate that transition metal fragment in planar chiral η⁶-transition metal complexes can be utilized as dynamic complexes with mobile chiral auxiliary.