Carbene complexes of titanium group metals - formation and reactivity

The principles in the formation of carbene complexes of titanium group meta ls are summarized. Characteristic examples of isolated as well as carbene c omplexes as intermediates are given. Selected structures and reactivity pat terns are discussed. Starting from the Tebbe-type chemistry, new aspects of carbene complexes with only one or without cyclopentadienyl ligands are il lustrated. In that direction, the formation of carbene complexes with N and O-donor ligands is described. Applications in co-ordination chemistry, org anic syntheses and material sciences are summarized. (C) 2001 Elsevier Scie nce B.V. All rights reserved.