925-55-3Relevant academic research and scientific papers
Lewis-acid assisted cross metathesis of acrylonitrile with functionalized olefins catalyzed by phosphine-free ruthenium carbene complex
Bai, Chen-Xi,Lu, Xiao-Bing,He, Ren,Zhang, Wen-Zhen,Feng, Xiu-Juan
, p. 4139 - 4142 (2005)
The exchange of the PPh3 ligand in the complex [1,3-bis(2,6-dimethylphenyl)4,5-dihydroimidazol-2-ylidene](PPh 3)-(Cl)2Ru=CHPh (7) for a pyridine ligand at ambient temperature leads to the formation of the stable phosphine-free carbene ruthenium complex [1,3-bis(2,6-dimethylphenyl)4,5-dihydroimidazol-2-ylidene] (C5H5N)2(Cl)2 Ru=CHPh (8). The resulted ruthenium complex exhibits highly catalytic activity for the cross metathesis of acrylonitrile with various functionalized olefins under mild conditions, and its activity can be further improved by the addition of a Lewis acid such as Ti(O′Pr)4. In the mixture products, the Z-isomer predominates. The Royal Society of Chemistry 2005.
Catalytic Hydrocyanation of Activated Terminal Alkynes
Tejedor, David,Delgado-Hernández, Samuel,Colella, Lucía,García-Tellado, Fernando
supporting information, p. 15046 - 15049 (2019/11/22)
A universal, practical and scalable organocatalytic hydrocyanation manifold to provide β-substituted acrylonitriles bearing an electron-withdrawing functionality has been implemented. The catalytic manifold operates under the reactivity generation principle “a good nucleophile generates a strong base”, and it uses 1,4-diazabicyclo[2.2.2]octane (DABCO) as the catalyst, activated terminal alkynes as substrates and acetone cyanohydrin as the cyanide source. The acrylonitriles obtained as E,Z mixtures are straightforwardly resolved by simple flash chromatography delivering the pure isomers in preparative amounts.
Evolution of structure and reactivity in a series of iconic carbenes
Zhang, Min,Moss, Robert A.,Thompson, Jack,Krogh-Jespersen, Karsten
scheme or table, p. 843 - 850 (2012/03/26)
We present experimental activation parameters for the reactions of six carbenes (CCl2, CClF, CF2, ClCOMe, FCOMe, and (MeO) 2C) with six alkenes (tetramethylethylene, cyclohexene, 1-hexene, methyl acrylate, acrylonitrile, and α-chloroacrylonitrile). Activation energies range from -1 kcal/mol for the addition of CCl2 to tetramethylethylene to 11 kcal/mol for the addition of FCOMe to acrylonitrile. A generally satisfactory analysis of major trends in the evolution of carbenic structure and reactivity is afforded by qualitative applications of frontier molecular orbital theory, although the observed entropies of activation appear to fall in a counterintuitive pattern. An analysis of computed cyclopropanation transition state parameters reveals significant nucleophilic selectivity of (MeO)2C toward α-chloroacrylonitrile.
Highly active phosphine-free carbene ruthenium catalyst for cross-metathesis of acrylonitrile with functionalized olefins
Bai, Chen-Xi,Zhang, Wen-Zhen,He, Ren,Lu, Xiao-Bing,Zhang, Zhi-Qiang
, p. 7225 - 7228 (2007/10/03)
The carbene ruthenium complex [1,3-bis(2,6-dimethylphenyl)-4,5- dihydroimidazol-2-ylidene](C5H5N)2(Cl) 2RuCHPh (8) was prepared by the reaction of [1,3-bis (2,6-dimethylphenyl)-4,5-dihydroimidazol-2-ylidene](PPh3)(Cl) 2RuCHPh (7) with pyridine and used as a highly effective catalyst for the cross-metathesis of acrylonitrile with various functionalized olefins.
