Facile functionalizations of permethyltitanocene dichloride to chiral persubstituted titanocene complexes

The new class of compounds arising from unconventinal additions of 1,4-disu bstituted 1,3-butadiynes to activated permethylmetallocene species of Ti an d Zr can be used in facile functionalizations. For example, the chiral prod uct 5, obtained from the addition of tBuC=CC=CtBu to activated permethyltit anocene, has been derivatized by simple means, e.g., hydrogen chloride, bro mine, or dihydrogen, affording practically useful functionalized titanocene compounds containing a chiral auxiliary ligand with an intramolecularly co ordinated (compound 7) or a free double bond (compounds 8a,b). The new comp lexes have been characterized spectroscopically. Additionally, X-ray crysta l structure analyses were performed for 7 and 8a,b.