20067-98-5Relevant academic research and scientific papers
Olefin metathesis catalysts containing acyclic diaminocarbenes
Rosen, Evelyn L.,Sung, Daphne H.,Chen, Zheng,Lynch, Vincent M.,Bielawski, Christopher W.
scheme or table, p. 250 - 256 (2010/04/04)
The first examples of ruthenium-based olefin metathesis catalysts containing acyclic diaminocarbene (ADC) ligands are reported. Complexes of the type (ADC)(SIMeS)Cl2Ru=CHPh and (ADC)Cl2Ru=CH(2- isopropoxy)Ph (ADC = N,N'-dimethylformamidin-2-ylidene or N,N'-bis(2,6-di- isopropylphenyl)-N,N'-dimethylformamidin-2-ylidene; SIMes = 1,3- dimesitylimidazolin-2-ylidene) were synthesized and studied in solution as well as in the solid state. Depending on their N-substituents and the metal center to which they were coordinated, the aforementioned ADC ligands were found to adopt different conformations. Preliminary investigations revealed that these Ru complexes exhibited high catalytic activities in a variety of olefin metathesis reactions at elevated temperatures and afforded cross-metathesis products with significantly lower E:Z ratios than catalysts containing analogous N-heterocyclic carbene ligands.
Comparative investigation of Hoveyda-Grubbs catalysts bearing modified N-heterocyclic carbene ligands
Ledoux, Nele,Linden, Anthony,Allaert, Bart,Vander Mierde, Hans,Verpoort, Francis
, p. 1692 - 1700 (2008/02/11)
This paper reports the structural modification of Hoveyda-Grubbs complexes through the introduction of either an N-alkyl-N′-mesityl heterocyclic carbene, an N-alkyl-N′-(2,6-diisopropylphenyl) heterocyclic carbene, or an N-alkyl-N′-alkyl heterocyclic carbe
Chloro-substituted Hoveyda-Grubbs ruthenium carbene: Investigation of electronic effects
Ettari, Roberta,Micale, Nicola
, p. 3574 - 3576 (2008/02/12)
A series of applications of cross and ring-closing metathesis has been made to investigate the application profile of the chloro-substituted Hoveyda-Grubbs ruthenium carbene in order to evaluate electronic effects resulting from the introduction of a chlorine atom para to the isopropoxy moiety of its parent catalyst.
Palladium-catalyzed, copper(I)-mediated coupling of boronic acids and benzylthiocyanate. A cyanide-free cyanation of boronic acids
Zhang, Zhihui,Liebeskind, Lanny S.
, p. 4331 - 4333 (2007/10/03)
(Equation Presented) A new method for the synthesis of nitriles is described. As a complement to the classic cyanation of aryl halides using cyanide sources and a transition metal catalyst, the palladium-catalyzed cross-coupling of thiocyanates with boronic acids in the presence of copper(I) thiophene-2-carboxylate (CuTC) affords nitriles in good to excellent yields.
Cross-metathesis of olefins directly substituted with an electron-withdrawing group using transition metal carbene catalysts
-
Page/Page column 14, (2008/06/13)
The invention pertains to the use of Group 8 transition metal alkylidene complexes as catalysts for olefin cross-metathesis reactions. In particular, ruthenium and osmium alkylidene complexes substituted with an N-heterocyclic carbene ligand and at least
New results on the functionalization of terminal alkenes by cross- metathesis reactions
Blanco, Olga M.,Castedo, Luis
, p. 557 - 558 (2007/10/03)
The ruthenium-catalyzed reaction of allylbenzene with several types of alkene provides good yields of the cross-metathesis products regardless of the structural characteristics of the alkene.
Highly Reactive Metallic Nickel: Reductive Homocoupling Reagent for Benzylic Mono- and Polyhalides
Inaba, Shin-ichi,Matsumoto, Hideyuki,Rieke, Reuben D.
, p. 2093 - 2098 (2007/10/02)
Metallic nickel, prepared by the reduction of nickel halides with lithium in glyme using naphthalene as an electron carrier, was found to be a useful reagent for the homocoupling of benzylic mono- and polyhalides.Benzyl halides reacted with metallic nickel at room temperature to give the corresponding 1,2-diarylethanes in good to high yields and functional groups on the aromatic ring such as methoxy, chloro, bromo, nitro, cyano, and alkoxycarbonyl groups were not affected under the conditions employed.Benzylic monohalides (1-(chloromethyl)- or 2-(bromomethyl)naphthalene, chlorodiphenylmethane, and 9-bromofluorene) also underwent coupling reactions with metallic nickel at room temperature to give the corresponding ethane derivatives.On the other hand, benzylic di- and trihalides such as α,α-dibromotoluene and α,α,α-trichlorotoluene yielded mixtures of cis and trans isomers of substituted ethenes.The intermediate of the reaction, benzylnickel complex, was trapped with electron deficient olefins such as methyl acrylate and acrylonitrile.
