Synthesis of Cyclopentadienyl Borate Ligands and Their Reactivity with Cp*Zr(CH3)3

This paper describes the synthesis of the new anionic cyclopentadienyl ligands Li[1,3-(CH 3 ) 3 SiC 5 H 4 B(C 6 F 5 ) 3 ] ( 3 ) and Li[C 5 H 5 B(C 6 F 5 ) 3 ] ( 4 ), in which the tris(perfluorophenyl)boron moiety has been linked directly to the Cp ring. The structure of 3 has been confirmed by X-ray crystallography. The reaction of 3 with Cp*Zr(CH 3 ) 3 produces the known sandwich complex [(CH 3 ) 3 SiCp)(Cp*)Zr(CH 3 ) 2 ] via loss of Li[CH 3 B(C 6 F 5 ) 3 ]. In contrast, reaction of 4 with Cp*Zr(CH 3 ) 3 produces the known complex (CH 3 Cp)(Cp*)Zr(CH 3 ) 2 .