A series of new titanium, Zirconium and hafnium complexes with the heteroatom chelating ligands hydroxyquinolines, hydroxypyridines and hydroxyimines were synthesized. The complexes were activated with MAO and successfully tested for the catalytic CH activation reactions of cyclooctane. They gave TONs of 1.7-18.7 (300 degrees C, 16 h) in homogeneous Solution. The TONs were clearly influenced by the ligand Structure. The endothermic CH activation reaction with group 4 metal catalysts is preferably carried out at higher reaction temperatures (300-400 degrees C). (C) 2008 Elsevier B.V. All rights reserved.