885-24-5Relevant articles and documents
Application of aromatic nitroethylene compound
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Paragraph 0487-0490, (2019/11/13)
The invention provides an application of an aromatic nitroethylene compound. Specifically, the invention provides the application of a compound as shown in a formula (I) and a stereoisomer or pharmaceutically-acceptable salt thereof in preparation of a medicament for regulating the dimer activity of a nuclear receptor RXR or treating neurodegenerative diseases.
Remarkable Ability of the Benzylidene Ligand To Control Initiation of Hoveyda–Grubbs Metathesis Catalysts
Basak, Tymoteusz,Grudzień, Krzysztof,Barbasiewicz, Micha?
supporting information, p. 3513 - 3523 (2016/07/29)
The structure of the chelating benzylidene ligand offers the unique ability to control the initiation of Hoveyda–Grubbs metathesis catalysts. Apart from steric and electronic effects acting on the step involving opening of the chelate ring, changes related to the following ligand-exchange process may also play a critical role. Our mechanistic model reveals that ligands substituted at the 6-position of the benzylidene ring enter the metathesis cycle in a nonoptimal chelating conformation, and thus the coordination number of the ruthenium center transiently increases to six (associative mechanism). In effect, the synthesis and initiation of the catalysts becomes difficult, and the energy barrier of the ligand-exchange process is controlled by the structure of the coordinating OR group. Moreover, we explain how isomeric naphthalene ligands affect the catalytic performance by an indivisible combination of steric and π-electron delocalization effects.
Is the Hoveyda-Grubbs complex a vinylogous fischer-type carbene? Aromaticity-controlled activity of ruthenium metathesis catalysts
Barbasiewicz, Michal,Szadkowska, Anna,Makal, Anna,Jarzembska, Katarzyna,Wozniak, Krzysztof,Grela, Karol
supporting information; experimental part, p. 9330 - 9337 (2009/10/01)
Three naphthalene-based analogues (4a-c) of the Hoveyda-Grubbs metathesis catalyst exhibited immense differences in reactivity. Systematic structural and spectroscopic studies revealed that the ruthenafurane ring present in all 2-isopropoxyarylidene chelates possesses some aromatic character, which inhibits catalyst activity. This aromatic stabilization within the chelate ring may be controlled by variation of the polycyclic core topology as was demonstrated for tetraline and phenanthrene derivatives (4d,e). General conclusions about a new mode of ligand-structure tuning in catalytic systems are presented.