The chemistry of the carbon-transition metal double and triple bond: annual survey covering the year 1998

This survey is intended to be a comprehensive summary of articles, which re port on the synthesis, reactivity, or properties of compounds that feature a multiple bond between carbon and a transition metal. Reactions that emplo y metal carbene complexes as transient intermediates generated through well -established routes [this subject was reviewed in 1998: M.P. Doyle, M.N. Pr otopopova, Tetrahedron 54 (1998) 7919] are not covered unless there is some effort to characterize the carbene complex intermediate. Although a determ ined effort has been made to include patents, in general only patents that focus on carbene complexes and not polymer products will be included. Only compounds which feature a multiple bond between one carbon atom and one tra nsition metal are discussed in this survey, thus bridging carbene and carby ne complexes are not covered unless there is a multiple bond to at least on e transition metal. The complexes of stable carbenes with transition metals have not been included; since the pi -donation component of these complexe s is minimal, there is no formal carbon-metal multiple bond [see J.C. Green , R.G. Scurr, P.R. Arnold, F.G.N. Cloke, J. Chem. Sec. Chem. Commun. (1997) 1963, and A.A. Danopoulos, D.M. Hankin, G. Wilkinson, S.M. Cafferkey, T.K. N. Sweet, M.B. Hursthouse, Polyhedron 16 (1997) 3879]. This survey has been divided into two sections, metal carbene (or alkylidene) complexes and met al carbyne (or alkylidyne) complexes; the carbene complex section represent s the vast majority of this article. The metal carbene section has been org anized according to metal, starting from the left side of the periodic tabl e. A special section focusing on alkene metathesis has been included prior to the discussion of carbene complexes of individual metals. The metal carb yne section has been organized according to reaction type. (C) 2000 Elsevie r Science B.V. All rights reserved.