Boriozirconocene Complexes

During the last ten years, the chemistry of 1,1-boriozirconocene complexes has been studied. Both hydrozirconation and hydroboration reactions are well established, and are widely applicable to a wide variety of vinyl and acetylene derivatives [1], Alkenylboranes and alkenyl zirconium compounds can also be readily prepared. Therefore, hydrometalla-tion of the corresponding alkenyl metals should offer a convenient method for preparing gem-boriozirconocenes [24]. 

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Stereospecific syntheses of temarotene (a retinoid) [130] and of chokols A and G (fun-gitoxic sesquiterpenes) [131—133] have been developed using 1,1-boriozirconocene complexes 45. 

Bimetallic Boriozirconocene Complexes with Planar Tetracoordinate Carbon... 

Preparation of Boriozirconocene Complex 16 (Scheme 7.5) [33] To a stirred ice-cooled suspension of the Schwartz reagent (0.26 g, 1 mmol) in dry CH2C12 (1 mL) was added a solution of B-hexenyl-9-BBN 15 (0.20 g, 1 mmol) in dry CH2C12 (1 mL). The resulting cloudy mixture became a dear yellow solution in 1 h at 0 °C (or 10 min at ambient temperature), indicating the formation of 16. 

Other classical reactions such as halogenation or amination with zirconium and boron compounds respectively are possible starting from 1,1-boriozirconocene complexes. 

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