Intramolecular activation of pendant alkenyl group as a tool for modification of the zirconocene framework
摘要:
The diphenyl zirconocene [(eta(5)-C(5)H(5)){eta(5)-C(5)H(4)CMe(2)(CH(2))(2)CH=CH(2)}ZrPh(2)] (2) was readily obtained from the corresponding zirconocene dichloride 1 and two equivalents of phenyllithium. Upon thermal treatment at 80 degrees C, complex 2 released benzene, with concomitant activation of the pendant double bond and formation of intramolecularly alpha-tethered zirconaindane [(eta(5)-C(5)H(5)){eta(5), eta(1), eta(1)-C(5)H(4)CMe(2)(CH(2))(2)CHCH(2)C(6)H(4)}Zr] (3). Both Zr-C sigma-bonds in 3 easily undergo nucleophilic reactions with two equivalents of HCl or one equivalent of Cl(2)PPh giving rise to zirconocene dichlorides with pendant phenyl group [(eta(5)-C(5)H(5)){eta(5)-C(5)H(4)CMe(2)(CH(2))(4)Ph}ZrCl(2)] (4) or with 1-phenylphosphindolinyl moiety [(eta(5)-C(5)H(5)){eta(5)-C(5)H(4)CMe(2)(CH(2))(2)cyclo-CHCH(2)C(6)H(4)P(Ph)}ZrCl(2)] (5), respectively. (C) 2011 Published by Elsevier B.V.