Organozirconium compounds,

Review Comprehensive Organic Synthesis, Eds. B. M. Trost and I. Fleming, Pergamon, Oxford (1991), Vol 5, Part 9.5, p 1163 

2 MeMgCl / ThCu(CN)Li / ROTf 2 MeMgCl / ThCu(CN)Li / PhCHjBr 

UC=CCH2C1/HC1 C1CHROR, ZnCl2 RCHO, cat Aga04 R2Zn (R = Me, Et)/RCHO 

HiCi CHCOR1, cat Ni(acac 2 H2C—CHCOR1. cat Ni(acac)2-i-Bu2AlH H2C=CHCOR CuOTf, Lil 

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The simplest reaction of zirconacyclopentadienes is their hydrolysis. It is characteristic for organo-early transition metal compounds the metal—carbon bond is easily hydrolyzed with acids to give free organic compounds. Similarly, deuterolysis of zirconacyclopentadienes, rather than protonolysis, affords deuterated compounds as expected (Eq. 2.9). The position of the deuterium is indicative of the position of the metal—carbon bond in the organozirconium compound. 

The use of organozirconium compounds as carbanion equivalents is greatly facilitated by trans metallations to the more reactive aluminum [11,100], copper [104—106], nickel [96—98], and palladium [99] derivatives. Copper-catalyzed carbon—carbon bond-forming reactions of alkyl- and alkenylzirconocene compounds have been particularly well studied, and have found considerable application in organic synthesis [107,108]. 

Although there are many different types of Zr(IV) and Zr(II) compounds, roughly 75—80% of the currently known well-characterized organozirconium compounds are zircono-cene derivatives [2]. They are even more dominant in the application of Zr to organic synthesis (Generalization 3). For this reason, essentially all the Zr compounds discussed in this chapter are ZrCp2 derivatives. 

Review. This review covers preparation and recent synthetically useful reactions of organozirconium compounds (178 references). Many of the recent bondforming reactions involve zirconocene derivatives. 

Review. Negishi and Takahashi1 have reviewed the preparation and synthetic uses of organozirconium compounds, mainly of the type RZrCp2X. Because of the high cost of Zr compounds, most stoichiometric applications allow for recovery of the metallic compounds. The review covers more than 100 research papers, all published since 1970. 

A benzoylation of an organozirconium compound is achieved by condensation with ben-zaldehyde, followed by the in situ Oppenauer oxidation of the resulting zirconium alkoxide... 

Introduction.—A text describing the chemistry of hafnium has been published.226 The structural,30,227 synthetic,3 and organometallic4 chemistry of zirconium and hafnium have been reviewed, and the compilation of the chemistry of organozirconium compounds has been revised.228 An account of the controversy following Urbain s claim, in 1911, to have isolated and identified element 72 has appeared.229... 

Herein is described how organoboron and additionally organozirconium compounds have proved to be valuable precursors to a variety of amines via hydrobora-tion-amination, or less frequently hydrozirconation-amination. 

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