Metallocene is a well known sandwich complex with two cyclopentadienyl ligands such as ferrocene. Recently, such metallocene compounds have been found to be very characteristic and they have become very important, not only in the area of organic synthesis, but also in polymerization in industry. Metal complexes with one cyclopentadienyl ligand have also become popular as half sandwich complexes. The number of researchers in the field of metallocenes has increased rapidly. However, the origin of the characteristic reactivity of metallocenes is not fully understood. In this volume, the chemistry of metal complexes with at least one cyclopentadienyl ligand is comprehensively covered by leading experts. Reactions discussed here are (i) natural product synthesis, (ii) catalytic asymmetric synthesis, (iii) cyclization reactions, (iv)catalytic reactions, (iv) polymerization reactions and (v) carbon-carbon bond cleavage reactions. The reader will have access to useful information about the current state of metallocene chemistry.