192649-53-9Relevant articles and documents
Polyelement substituted cyclopentadienes and indenes - Novel ligand precursors for organotransition metal chemistry
Rufanov, Konstantin,Avtomonov, Evgeni,Kazennova, Nadezhda,Kotov, Vasilij,Khvorost, Alexander,Lemenovskii, Dmitry,Lorberth, Joerg
, p. 361 - 373 (2007/10/03)
A series of polyelement substituted cyclopentadienyl and indenyl boranes and arsanes containing Me3Si-, Me3Sn-was synthesised; (C5H4SiMe3)BX2 (2, X = Cl; 3, X = Br) and (C9H6SiMe3)BX2 (4, X = Cl; 5, X = Br) were obtained by Si/B exchange reaction in a low yield when X = Cl and in a moderate yield when X = Br, whereas Flu(SiMe3)2 does not react with BBr3 at all. PhB(C5H4SiMe3)2 (6) and PhB[C5H3(SiMe3)2]2 (7) were synthesised using appropriate thallium cyclopentadienides in high yields, 81% and 99% respectively. More bulky indenyl derivatives TrsB(C9H7)2 (8, Trs = (Me3Si)3C-), PhB(C9H6SiMe3)2 (9), Ph2B(C9H6SiMe3) (10) were prepared by metathesis reactions of lithium indenides with boron halides in high yields. A subsequent transmetallation of C9H6(SnMe3)2 with PhBCl2 followed by addition of ZrCl4 gave (η-5-C9H6SnMe2Cl)2ZrCl2 (11) in the form of one of two possible diastereomers in high yield. C9H6(SiMe3)SnMe3 reacts with BCl3 to give the appropriate bis-indenyl derivative, that was easily converted to the ansa-zirconocene complex [MeB(η5-C9H6)2]ZrCl2 (12). The sterically demanding bis-indenyl ligand 8 underwent direct deprotonation by t-BuLi, affording [TrsB(η5-C9H6)2]ZrCl2 (13) by in situ reaction with Me3SnCl and ZrCl4. Indenylarsanes (C9H7)3As (14), t-BuAs(C9H7)2 (15), C9H7AsMe2 (16) and (C9H6SiMe3)AsMe2 (17) were synthesised by reactions of lithium indenides with asenic halides in good to excellent yields. All these compounds were characterized by analytical and spectroscopic data (NMR, MS). 14 and 15 exist as complex isomeric mixtures with the arsenic atom in the allylic position of the indenyl ring; the crystal structure of a meso form of 15 was determined by X-ray diffraction methods. 17 consists of two isomers with a vinylic (17a) and an allylic (17b) Me3Si substituent. Stannylation of 16 by Me3SnNEt2 led exclusively to the diallylic derivative (C9H6AsMe2)SnMe3 (18) in quantitative yield. The latter was readily converted to a polymeric, half-sandwich indenyl zirconocene [η5-(C9H6AsMe2)ZrCl3]n (19) in high yield. Further reaction of 19 with Cp * Li resulted in the formation of a new arsano substituted bent metallocene complex [η5-(C9H6AsMe2)-η5-(C5Me5)]ZrCl2 (20) in good yield.
