59474-22-5Relevant academic research and scientific papers
Selective Oligomerization and [2 + 2 + 2] Cycloaddition of Terminal Alkynes from Simple Actinide Precatalysts
Batrice, Rami J.,McKinven, Jamie,Arnold, Polly L.,Eisen, Moris S.
, p. 4039 - 4050 (2015/09/01)
A catalyzed conversion of terminal alkynes into dimers, trimers, and trisubstituted benzenes has been developed using the actinide amides U[N(SiMe3)2]3 (1) and [(Me3Si)2N]2An[κ2-(N,C)-CH2Si(CH3)N(SiMe3)] (An = U (2), Th (3)) as precatalysts. These complexes allow for preferential product formation according to the identity of the metal and the catalyst loading. While these complexes are known as valuable precursors for the preparation of various actinide complexes, this is the first demonstration of their use as catalysts for C-C bond forming reactions. At high uranium catalyst loading, the cycloaddition of the terminal alkyne is generally preferred, whereas at low loadings, linear oligomerization to form enynes is favored. The thorium metallacycle produces only organic enynes, suggesting the importance of the ability of uranium to form stabilizing interactions with arenes and related π-electron-containing intermediates. Kinetic, spectroscopic, and mechanistic data that inform the nature of the activation and catalytic cycle of these reactions are presented. (Chemical Equation Presented).
Et2SiH2 assisted the selective dimerization of terminal alkynes catalyzed by Cp*2UMe2
Wang, Ji Quan,Eisen, Moris S.
, p. 97 - 107 (2007/10/03)
A practical approach has been developed for the catalytic synthesis of short oligomers, dimers and/or trimers of terminal alkynes. The method allows control of the extent and, in some cases, the regiospecificity in the catalyzed oligomerization of terminal alkynes promoted by bis(pentamethylcyclopentadienyl)uranium dimethyl complex (Cp*2U(CH3)2, Cp= C5Me5). The metallocene precursor is known to promote the simultaneous production of a large number of differently sized oligomers in the presence of terminal alkynes. However, the addition of a specific secondary silane ensures the selective synthesis of short oligomers.
