Selective monolithiation of 1,1 '-dibromoferrocene applied to the synthesis of new unsymmetrical 1,1 '-disubstituted ferrocenyl ligands

A novel convenient method for preparing unsymmetrical 1,1'-disubstituted fe rrocenyl ligands by using the readily accessible 1,1'-dibromoferrocene as a precursor is described. The method is of interest for modifying the chelat ing ferrocenyl ligands in view of the growing influence of homogeneous cata lysis in organic synthesis, manipulation of materials and production of hig h optical yield.