Carbenoid insertions and cyclometallations of zirconacycles

The synthesis of zirconacycles and further elaborations to produce a wide variety of<br/>carbocyclic and heterocyclic systems is well established. This thesis focuses on the<br/>insertion of chloro(aryl)methyllithiums (benzyl carbenoids) into a range of<br/>zirconacyclopentenes and zirconacyclopentanes.<br/><br/>Benzyl carbenoid insertion into a zirconacyclopentene generated the<br/>zirconacyclohexene via a 1,2-metalate rearrangement. A low temperature quench<br/>afforded the expected benzyl inserted product. Quenching at higher temperatures<br/>afforded a styrene containing product. It was proposed that the styrene product was<br/>formed via a novel endocyclic cyclometallation to afford a zirconocene n2-alkene<br/>complex followed by decomplexation. A wide variety of zirconacyclopentenes and<br/>benzyl carbenoids have been investigated.<br/><br/>A range of benzyl carbenoids were inserted into a zirconacyclopentane to afford the<br/>expected benzyl inserted product. Double benzyl carbenoid insertion was also observed<br/>and afforded a mono-alkene product. It was speculated that the bis-inserted products<br/>were formed via a zirconacycloheptane followed by a novel endocyclic<br/>cyclometallation.<br/><br/>Having shown that zirconacyclohexenes underwent an endocyclic cyclometallation to<br/>afford a zirconocene n2-alkene complex, the concept of intramolecular trapping of the<br/>zirconocene n2-alkene complex, to generated bicyclic compounds, was investigated.

Name dc:type.qualificationname

Ph.D.

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Southampton

Year dc:date.issued

2009

Author dc:creator

• Norman, Louise Daisey

Advisor dc:contributor.advisor

• Whitby, Richard J.