| Abstrakt: |
The reaction of the titanacycle CpTi(NPt-Bu3)(C4H8) (1) with benzyl halides, 4-bromo-1-butene, and allyl chloride proceeds with loss of ethylene to give CpTiX(NPt-Bu3)(CH2Ph) (X Cl, 3; Br,4), CpTiBr(NPt-Bu3)(CH2CH2CHCH2) (5), and CpTiCl(NPt-Bu3)(CH2CHCH2) (6), respectively. Complexes 4 and 6 were readily alkylated to CpTiMe(NPt-Bu3)(CH2Ph) (7) and CpTiMe(NPt-Bu3)(CH2CHCH2) (8), respectively. Loss of ethylene also occurs on reaction of 1with bipyridine to give CpTi(NPt-Bu3)(bipy) (9). In contrast, reaction of 1 with ClSiMePh2in the presence of PMe3gave CpTiCl(NPt-Bu3)(CH2CH2SiPh2Me) (10). In a similar fashion, the two-carbon derivatives CpTiCl(NPt-Bu3)(CH2CH2SiMe3) (11), CpTiCl(NPt-Bu3)(CH2CH2Si(SiMe3)3) (12), CpTi(NPt-Bu3)(CH2CH2SiMe3)(OSO2CF3) (13), CpTiCl(NPt-Bu3)(CH2CH2Snn-Bu3) (14), CpTiCl(NPt-Bu3)(CH2CH2SiCl3) (15), and CpTiCl(NPt-Bu3)(CH2CH2)2SiCl2(16) were produced. In the absence of PMe3, reaction of 1 with SiCl4and ClSnMe3gave the four-carbon derivatives CpTiCl(NPt-Bu3)(CH2CH2CH2CH2SiCl3) (17) and CpTiCl(NPt-Bu3)(CH2CH2CH2CH2SnMe3) (18), while reaction of 1 with ClSnPh3gave only the two-carbon chain derivative CpTiCl(NPt-Bu3)(CH2CH2SnPh3) (19). Nonetheless, in the presence and absence of PMe3reaction of 1 with ClBcat or ClPPh2gave the analogous two- and four-carbon derivatives CpTiCl(NPt-Bu3)(CH2CH2Bcat) (20), CpTiCl(NPt-Bu3)(CH2CH2CH2CH2Bcat) (21), CpTiCl(NPt-Bu3)(CH2CH2PPh2)(22), and CpTiCl(NPt-Bu3)(CH2CH2CH2CH2PPh2) (23), respectively. The corresponding species CpTiCl(NPt-Bu3)(CH2CH(CH3)CH(CH3)CH2PPh2) (24) was prepared from CpTi(NPt-Bu3)(CH2CHMe)2(2), while complexation of 23 and 24 afforded CpTiCl(NPt-Bu3)(CH2CH2CH2CH2PPh2)RhCl(cod) (25) and CpTiCl(NPt-Bu3)(CH2CH(CH3)CH(CH3)CH2PPh2)RhCl(cod) (26). The mechanisms affording the functionalized two- and four-carbon derivatives above are discussed and the implications considered. |
