Enantiospecific synthesis of a planar chiral fluorenylzirconium ansa-metallocene: synthesis and structures of [1-(9-fluorenyl)- and [1-(1-methyl-9-fluorenyl)-2-(2-indenyl)naphthalene]zirconium dichloride

摘要

Di-lithiation of +ac(R)-1-methyl-9-[2-(2-indenyl)-1-naphthyl]fluorene, +ac(R)-6, generates an axially chiral fluorenyl ligand, (a-S)-10, which on reaction with ZrCl4 enantiospecifically provides the planar chiral ansa-zirconocene (p-S)-[1-(1-methyl-9-fluorenyl)-2-(2-indenyl)naphthalene]zirconium dichloride, (p-S)-8; single crystal X-ray structures have been determined for the racemic ansa-zirconocene rac-8 and the related C-s-symmetric ansa-zirconocene 7. [References: 12]