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Alkoxyalumoxanes (ROAIO)n-Synthesis and Properties

Kunicki A., Pasynkiewcz S., Jankowski J., Mańk B.

Polish Journal of Chemistry

2004

Vol. 78 / nr 10

1857-1864

Two reaction methods were employed to prepare alumoxanes of general formula [(RO)AlO]n. The first one from Et3Al, H2O and ROH [R = CH3, (CH3)2CH]; the second one from Et3Al, ROH [R = (CH3)2CH, CH3(CH2)9] and H2O. The properties, chemical composition, aggregation and proposed structure of the final products are discussed based on gel permeation chromatography, molecular weight determination and spectroscopic data.

Nickel Mediated Coupling of Organic Ligands

Pasynkiewcz S., Pietrzykowski A., Olędzka E., Wang J.

Polish Journal of Chemistry

2003

Vol. 77 / nr 5

701-707

Reactions of nickelocene, NiCp2, with organolithium compounds RLi (R = -C_CPh; -CPh=CPh2; -CPh3, -CPh2SiMe3), where R does not contain _- and _-hydrogen atoms, have been studied. It was found that {CpNiR}, formed in the first step of the reaction, underwent coupling with the formation of {(NiCp)2} and R-R. As organolithium substrates are readily available, and yield of coupling products was high (from over 60% to ~ 90%), the studied reactions could be applied as synthetic methods for preparation of wide range of R-R type organic compounds. In order to improve yield of the products and to prevent very active {(NiCp)2} species from further reactions, NiCp2 and LiR were reacted in the presence of PhC_CMe, what led to the formation of only two products: (NiCp)2_PhC_CMe complex and R-R. These products were easily separated by column chromatography on neutral alumina, leading to the isolation of R-R in high yield.