Mixed Disilyl‐Substituted Cyclopentadiene Derivatives and Corresponding Zirconium, Molybdenum and Tungsten Compounds

Abstract

AbstractThe mixed disilyl‐substituted cyclopentadiene C5H4[SiMe2(CH=CHCH3)](SiMe3) (2) has been synthesized in a one‐pot reaction by alkylation, deprotonation and silylation of C5H5(SiMe2Cl). The analogous olefin‐tethered cyclopentadiene C5H4[SiMe2(CH2CH=CH2)](SiMe3) (3) has been obtained through traditional metathesis routes from Li[C5H4(SiMe3)] and the chloroallylsilane SiMe2(CH2CH=CH2)Cl. The corresponding mixed disilyl‐substituted cyclopentadienyllithium salts Li[C5H3‐1‐SiMe2R‐3‐SiMe3] [R = CH=CHCH3 (cis+trans‐4); R = CH2CH=CH2 (5)] were used to isolate the chiral zirconium compounds [ZrX(η5‐C5H4SiMe2‐η1‐NtBu)(η5‐C5H3‐1‐SiMe2R‐3‐SiMe3)] [X = Cl, R = CH=CHCH3 (cis+trans‐6); R = CH2CH=CH2 (7); X = CH3, R = CH=CHCH3 (cis+trans‐8); R = CH2CH=CH2 (9)] and group 6 derivatives [MH(η5‐C5H3‐1‐SiMe2R‐3‐SiMe3)(CO)3] [R = CH=CHCH3, M = Mo (cis+trans‐10), M = W (cis+trans‐11); R = CH2CH=CH2, M = Mo (12) and M = W (13)], which have been fully characterized. The behaviour of metal compounds 8–13 has beenstudied and compared with that previously reported for monosubstituted alkene–silylcyclopentadienyl systems [Zr(CH3)(η5‐C5H4SiMe2‐η1‐NtBu)[(η5‐C5H4SiMe2)(CH2CH=CH2)] and [MH(η5‐C5H4SiMe2‐η1‐NtBu)[(η5‐C5H4SiMe2)(CH2CH=CH2)](M = Mo, W).