55682-74-1Relevant academic research and scientific papers
Lanthanide-Catalyzed Reversible Alkynyl Exchange by Carbon–Carbon Single-Bond Cleavage Assisted by a Secondary Amino Group
Shao, Yinlin,Zhang, Fangjun,Zhang, Jie,Zhou, Xigeng
supporting information, p. 11485 - 11489 (2016/10/24)
Lanthanide-catalyzed alkynyl exchange through C?C single-bond cleavage assisted by a secondary amino group is reported. A lanthanide amido complex is proposed as a key intermediate, which undergoes unprecedented reversible β-alkynyl elimination followed by alkynyl exchange and imine reinsertion. The in situ homo- and cross-dimerization of the liberated alkyne can serve as an additional driving force to shift the metathesis equilibrium to completion. This reaction is formally complementary to conventional alkyne metathesis and allows the selective transformation of internal propargylamines into those bearing different substituents on the alkyne terminus in moderate to excellent yields under operationally simple reaction conditions.
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).
NbCl3-catalyzed [2+2+2] intermolecular cycloaddition of alkynes and alkenes to 1,3-cyclohexadiene derivatives
Obora, Yasushi,Takeshita, Keisuke,Ishii, Yasutaka
experimental part, p. 428 - 431 (2009/06/28)
NbCl3(DME)-catalyzed [2+2+2] intermolecular cycloaddition of alkynes and alkenes was successfully achieved to give 1,4,5-trisubstituted-1,3- cyclohexadiene derivatives in good yields. The Royal Society of Chemistry 2009.
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.
