There are only few topics in organometallic chemistry, which have stimulated research activities in as many areas, as transition-metal carbene (alkylidene) complexes. About 25 years after the first planned synthesis of a carbene complex in E.O. Fischer's laboratory in Munich the NATO Advanced Research Workshop on Transition-Metal Carbene Complexes was the first meeting which,brought together scientists from different disciplines to discuss inorganic, organic, theoretical structural catalysis-related aspects of metal carbene chemistry. The 70th birthday of Professor E.O. Fischer was a good occasion for this enterprise. The organizers of the meeting (K.D. Dotz, Marburg; F.R. KreiBl, Munchen; U. Schubert, Wurzburg) were encouraged by the fact that most of the leading scientists in this area were able to participate in the workshop. The very high standard of the contributions is reflected in this book, which contains papers from the majority of the participants. The Proceedings show the state of the art in metal carbene chemistry and will hopefully be a landmark in the development of this area of chemistry. Generous financial support for the workshop and for the preparation of this book was provided by the Scientific Affairs Division of NATO and some companies. The organizers also acknowledge the efforts of the staff of the Bildungs zentrum der Hans-Seidel-Stiftung in Wild bad Kreuth for creating a pleasant and stimulating atmosphere during the conference.

Zusammenfassung
Proceedings of the NATO Advanced Research Workshop on Transition-Metal Carbene Complexes, Wildbad Kreuth, Germany, September 25-30, 1988

Inhalt
Early Days of Transition-Metal Carbene Complexes.- Carbyne to Carbene Conversion Reactions at Hetero-Nuclear Dimetal Centres.- Stable, Terminal Methylene (=CH2) Complexes of Ruthenium, Osmium and Iridium.- Metal-Mediated Cyclization of Alkynes and Carbenes: A New Route Toward Highly Substituted Cyclopentanoids.- N, N?,N?, N?-Functionalised Electron-Rich Alkenes and Their Role in Transition-Metal Chemistry.- Synthesis and Properties of Chlorotris(1,3 Dibenzylimidazolidin-2-Ylidene)Rhodium(I) and of Some Related Compounds.- Synthesis of Cyclic and Acyclic Carbene Complexes Derived from Isocyanide Ligands in Complexes of Palladium(II) and Platinum(II).- Hydridocarbene Complexes of Platinum(II) Derived from Electrophilic Cleavage of C-F Bonds in Hydridotrifluoromethyl Compounds by Proton Acids.- Potential Role of Metal-Carbene Complexes in the Development of Polymer-Supported Coordination Chemistry.- Carbene Complexes Derived from the Activation of Isocyanides and Alkynes by Electron-Rich Metal Centres.- Synthesis of Isonitrile Substituted Tungsten Carbyne Complexes and Their Reactions with Electrophiles.- Metal Carbene Complexes from Alkynes.- Carbene Ligands and Metal-Carbon-Sulfur Ring Compounds of Tungsten and Iron.- Synthesis and Reactions of ?2-Carbene Complexes.- Cyanocarbene Dinuclear Derivatives of Iron.- Organometallic Synthons for Anionic Thiocarbene and ?-Deprotonated Thione Complexes.- Opening of Oxirane and Oxetane Rings by the Conjugate Base of the Pentacarbonyl(Methoxy-Methyl)Chromium Complex in the Presence of BF3.Et2O.- Formation of Metal-Carbon Double Bonds by R3SiX Elimination.- Ligand Migrations to Coordinated Carbene.- New (Butadiene)Zirconocene Carbene Complex Chemistry.- Structure and Reactivity of the Tungsten Vinylcarbene Complexes[W(=CPh-CH=CRMe)Br2(CO)2L] (R = H,Me; L = 4-Picoline). Is the Vinyl Group Acting as a Pure ?-Donor Ligand?.- Dioxophosphinomethylidene Molybdenum(VI)Complexes.- Reactions of Benzylidene(Pentacarbonyl) Complexes.- In-Situ Generation of the Benzylidene Complex [Cp(CO)2W=CH(Tol)]+ and Its Reactions with Alkynes.- Carbene Complexes in Selective Organic Synthesis: Novel Applications of Carbene Annulation Reactions.- Formation of C=C Double Bonds by Novel Insertion Reactions of Allenes, Heterocumulenes and Acid Amides Into M=C Bonds of Fischer Carbene Complexes.- Photolytic Reactions of Chromium Carbene Complexes in the Synthesis of Optically Active, Biologically Active Compounds.- 53Cr Nuclear Magnetic Resonance Studies of Pentacarbonylchromium Carbene Complexes.- Synthesis, Structure and Reactivity of Highly Electrophilic Carbene Complexes of the Type C5H5(CO)(L)Fe=CHR+.- The Carbene Complex Route To Donor-Acceptor-Substituted Cyclopropanes.- Reaction between Pentacarbonylchromium or Tungsten Complexes of Carbenes and Terminal Phosphinidenes.- Alkene-Carbene Complexes of Tungsten and Chromium: Their Reaction with Alkynes.- Reactions of Acetylenes and Alkenes Induced by Catalysts of Olefin Metathesis.- The Reactions of Mo(NtBu)(=CHtBu)(CH2But)2 with Alcohols: Competition between Molybdenum to Carbon Single and Double Bond Reactivities.- The Metathesis Polymerization of Norbornene and Its Derivatives Initiated by Tungsten-Carbene Complexes: Relative Stability of the Intermediate Tungstenacyclobutane Complexes.- The Preparation and Reactivity of Several Alkylidene Complexes of the Type W(CHR?)(N-2, 6-C6H3-iPr2)(OR)2 and Related Tungstacyclobutane Complexes: How the Choice of or Ligand Controls Structure and Metathesis Activity.- On the Presence of Dichloro-W-Carbenes inPhoto-Catalytic Olefin Metathesis Reactions.- Studies on Stoichiometric and Catalytic Metathesis and other Reactions of Imines with Fischer Type Carbene Tungsten Complexes. Part XVI.- Metathesis of Alkenes and Polymerisation of Alkynes with Heterogeneous and Homogeneous Schrock-Type Carbene Complexes. Part XVII.- Easily Accessible Methylene Complexes of Molybdenum and Tungsten: Structure and Application in Organic Synthesis.- Organometallic Reagents Prepared by the Reduction of Dihaloalkanes with Low Valent Titanium or Chromium.- Carbene Synthons in Monothioacetal Reactions.- The Determination of Electron Density Distributions in Organometallic Compounds Recent Experimental Results.