TY - JOUR
T1 - Silicon-Carbon bond cleavage reactions of Ansa tungstenocene compounds
T2 - The [Me2Si] bridge as a site for metallocene functionalization
AU - Zachmanoglou, Cary E.
AU - Lee, Hyosun
AU - Seung, Ho Jang
AU - Pang, Keliang
AU - Parkin, Gerard
PY - 2008/8/12
Y1 - 2008/8/12
N2 - [Me2Si(CpMe2)2]W(H)Cl is obtained via reaction of WCl6 with a mixture of [Me2Si(Cp Me2)2]Li2 and NaBH4, from which the dichloride [Me2Si(CpMe2)2]WCl2 is obtained via treatment with CHCl3. [Me2Si(Cp Me2)2]WCl2 provides a means to access other ansa tungstenocene compounds, such as [Me2Si(CpMe2) 2]WH2, [Me2Si(CpMe2) 2]WMe2, and [Me2Si(CpMe2) 2]WCO. Of most interest, the reactions of [Me2Si(Cp Me2)2]W(H)Cl with organolithium reagents do not yield simple ansa tungstenocene derivatives. Specifically, the reactions of [Me 2Si(CpMe2)2]W(H)Cl with MeLi, BunLi, or PhLi result in the formation of mixed-ring tungstenocene compounds resulting from C-Si cleavage and functionalization of the ansa bridge, namely (Cp Me2)(η5,κ1-C5H 2Me2SiMe2CH2)WH, (Cp Me2)[η5,κ1-C5H 2Me2Si(Me)(Bun)CH2]WH, and (Cp Me2)[η5,κ1-C5H 2Me2SiMe2(C6H4]WH, respectively. In contrast to the C-Si cleavage achieved by MeLi, Bu nLi, and PhLi, the ansa bridge of [Me2Si(Cp Me2)2]W(H)Cl is inert to ButLi and the product obtained is the fulvene ("tuck-in") complex [Me2Si(Cp Me2)(η6-C5MeH2CH2)] WH derived from dehydrohalogenation.
AB - [Me2Si(CpMe2)2]W(H)Cl is obtained via reaction of WCl6 with a mixture of [Me2Si(Cp Me2)2]Li2 and NaBH4, from which the dichloride [Me2Si(CpMe2)2]WCl2 is obtained via treatment with CHCl3. [Me2Si(Cp Me2)2]WCl2 provides a means to access other ansa tungstenocene compounds, such as [Me2Si(CpMe2) 2]WH2, [Me2Si(CpMe2) 2]WMe2, and [Me2Si(CpMe2) 2]WCO. Of most interest, the reactions of [Me2Si(Cp Me2)2]W(H)Cl with organolithium reagents do not yield simple ansa tungstenocene derivatives. Specifically, the reactions of [Me 2Si(CpMe2)2]W(H)Cl with MeLi, BunLi, or PhLi result in the formation of mixed-ring tungstenocene compounds resulting from C-Si cleavage and functionalization of the ansa bridge, namely (Cp Me2)(η5,κ1-C5H 2Me2SiMe2CH2)WH, (Cp Me2)[η5,κ1-C5H 2Me2Si(Me)(Bun)CH2]WH, and (Cp Me2)[η5,κ1-C5H 2Me2SiMe2(C6H4]WH, respectively. In contrast to the C-Si cleavage achieved by MeLi, Bu nLi, and PhLi, the ansa bridge of [Me2Si(Cp Me2)2]W(H)Cl is inert to ButLi and the product obtained is the fulvene ("tuck-in") complex [Me2Si(Cp Me2)(η6-C5MeH2CH2)] WH derived from dehydrohalogenation.
UR - http://www.scopus.com/inward/record.url?scp=49649105020&partnerID=8YFLogxK
U2 - 10.1073/pnas.0803089105
DO - 10.1073/pnas.0803089105
M3 - Article
C2 - 18635687
AN - SCOPUS:49649105020
SN - 0027-8424
VL - 105
SP - 11060
EP - 11065
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 32
ER -