摘要:
Reaction of the disilylcyclopentadiene 1,1-[SiMe2(CH2CH=CH2)](2)C5H4 with NbCl5 gave the new allylsilyl-substituted monocyclopentadienyl niobium complex [Nb{eta(5)-C5H4SiMe2(CH2CH=CH2)}Cl-4]. This compound was reacted with LiNHtBu or NH(2)tBu to give the imido derivative [Nb{eta(5)-C5H4SiMe2(CH2CH=CH2) (NtBu)Cl-2], which was further alkylated to the imido alkyl complexes [Nb{eta(5)-C5H4SiMe2(CH2CH=CH2)}(NtBu)Cl-2] (R=Me, CH2Ph) and [Nb{eta(5)-C5H4SiMe2(CH2CH=CH2)}(NtBu)Cl (CH2Ph)]. Reaction of the imido complexes with the corresponding lithium cyclopentadienides gave the dicyclopentadienyl-imido complexes [M(eta(5)-C5R5){eta(5)-C5H4SiMe2(CH2CH=CH2)}(NtBu)Cl] (M = Nb, Ta; R = H, Me). Metallocene dichlorides [M(eta(5)-C5R5){eta(5)-C5H4SiMe2(CH2CH=CH2)}Cl-2] (M = Nb, Ta; R = H, Me) were easily prepared by reduction with Na/Hg and simultaneous transmetallation of [Ta(eta(5)-C5R5)Cl-4] with Li[C5H4SiMe2(CH2CH=CH2)] and of [Nb{eta(5)-C5H4SiMe2(CH2CH=CH2)}Cl-4] with Li(C5R5). All of the new compounds have been characterized by elemental analysis, and IR and NMR spectroscopy. (c) 2004 Elsevier B.V. All rights reserved.