Reactivity of fully methylated eta~3:eta~4-allylidene-(eta~5-cyclopentadienyl)titanium(II) towards alkynylketones. The crystal structure of an unexpected 1:2 adduct

摘要

Fully methylated eta~3:eta~4-allylidene-(eta~5-cyclopentadienyl)titanium(II) (1) racts with alkynylketones RC ident to CC(O)Me (R = SiMe_3 (3a) and ferrocenyl (3b)) to give the expected products of the C=O group inseriton into one Ti-CH_2 bond 4a and 4b, respectively. Compound 4a could not be isolated in pure form due to its high solubility; a minor product of two-fold addition (5) was isolated instead. Complex 5, formally [1 + 2 3a], was characterized as a monocyclopentadienyl bis(alkoxy)organyl complex, where the alkoxyorganyl ligand arises from C = O insertion into one Ti-CH_2 and the Ti-C(cyclopentadienyl) bonds. The structures of compouns 4b and 5 were determined by single-crystal X-ray diffraction.