"Metallocenes" have been used for complexes which have sandwich structures with two cyclopentadienyl ligands since the discovery offerrocene. Recently metal complexes having one cyclopentadienyl ligand have also been classified as a member ofmetallocene derivatives.One important discovery in this area is the olefin polymerization catalyzed by metallocene complexes ofearly transition metals such as zirconium and titanium.In particular,the structure of the metallocene catalyst has a remarkable effect on the structure ofthe polymers.This discovery has had a strong impact on the industry. The area oforganic synthesis using metallocenes ofearly transition metals has been lagging behind synthesis using late transition metals.Many ofthe reactions have been stoichiometric for some time.Among them hydrozirconation ofunsaturated compounds has been widely used.In the last two decades,however,a lot ofcatalytic reactions including asymmetric synthesis
have been developed.Now this area has become quite attractive for many researchers in organic synthesis. This book is presented as a volume of Topics in Organometallic Chemistry, aiming at giving an overview ofthe chemistry ofmetallocenes.In particular, in this book we focused on,(i) hydrozirconation and its application to natural product synthesis,(ii) the asymmetric carboalumination reaction,(iii) the cyclization reaction using metallocenes,(iv) catalytic reactions using metallocenes,(v) olefin polymerization and (vi) carbon-carbon bond cleavage reactions using metallocenes.I would like to express my thanks to all contributors to this book.