Intermolecular C-H Activation by Reactive Titanocene Alkylidene Intermediates

Thermal α-H abstraction from (C5H4R)2Ti(CH2CMe3)2 (R = H, Me) produces reactive titanocene neopentylidene intermediates under mild conditions, that can either be trapped with PMe3 to yield the alkylidene complexes (C5H4R)2Ti(CHCMe3)PMe3, or add C-H bonds of hydrocarbon substrates R´H (R´H = benzene, p-xylene) to the Ti=C double bond to produce (C5H4R)2Ti(CH2CMe3)R´; an alternative reaction pathway, insertion of the alkylidene moiety into the cyclopentadienyl C-C bond, has been observed in the presence of THF.