Synthesis of novel chiral cyclopentadienes: synthesis of chiral iron complexes and the crystal structures of compund (8) and [(?5-C5(Me)4C(H)(CH3)(C 2H5))Fe(CO)-(?4-diphenylbutadiene)] +[BF4]-

Two new functionalized tetramethylcyclopentadiene (FTMCP) ligands are described: optically active (1S)-1-(6-methoxynaphthalenyl)-1-(2,3,4,5-tetramethylcyclopentadienyl)-ethane (2) and racemic 1-methyl-1-(2,3,4,5-TMCP)propane (3). These ligands were used to synthesize cationic diene complexes [(è5-FTMCP)Fe(CO)(è4-diene)]+[BF4]- (diene ) diphenylbutadiene (11), methyl hexa-2,4-dienoate (10)). The absolute configuration of the ligand 2 was determined from the crystal structure of complex [(è5-(1S)-1-(6-methoxynaphthalenyl)-1-(2,3,4,5-tetramethylcyclopentadienyl)-ethane)Fe(CO)2SnCl3] (8).