INTERMOLECULAR C-H ACTIVATION BY REACTIVE TITANOCENE ALKYLIDENE INTERMEDIATES

Thermal alpha-H abstraction from (C(5)H(4)R)(2)Ti(CH(2)CMe(3))(2) (R = H, Me) produces reactive titanocene neopentylidene intermediates unde r mild conditions, that can either be trapped with PMe(3) to yield the alkylidene complexes (C(5)H(4)R)(2)Ti(CHCMe(3))PMe(3), or add C-H bon ds of hydrocarbon substrates R'H (R'H = benzene, p-xylene) to the Ti=C double bond to produce (C(5)H(4)R)(2)Ti(CH(2)CMe(3))R'; an alternativ e reaction pathway, insertion of the alkylidene moiety into the cyclop entadienyl C-C bond, has been observed in the presence of THF.