Synthetic applications of organozirconocenes

Abstract

Alkenyl- and alkylzirconocenes are readily available by hydrozirconation of alkynes and alkenes, respectively. Due to the relatively low nucleophilicity of the carbon-zirconium bond in these organometallics, transmetalation schemes have been developed for carbon-carbon bond formations. Especially, in situ transmetalation to copper(I) and zinc(II) species can be used for selective alkylation reactions with organic electrophiles. Alternatively, conversion of organozirconocenes to the corresponding cationic complexes enhances their reactivity considerably. Synthetic applications include protocols for orthoester formations and Diels-Alder catalysis as well as natural products (Curacin A, Manumycin) synthesis.