154735-85-0Relevant articles and documents
Ruthenium-catalysed ortho alkylation of hydroxyacetophenones; The functionalisation of ring C aromatic diterpenoids
Harris, Paul W. R.,Woodgate, Paul D.
, p. 339 - 341 (1996)
Reaction of 2-, 3-, or 4-hydroxyacetophenone with a catalytic amount of a ruthenium complex and excess of a vinyltrialkoxysilane results in ortho alkylation in high yield, providing that a suitable protecting group is used. Bicyclic and tricyclic analogues react similarly.
Alkylation of monomeric, dimeric, and polymeric lignin models through carbon-hydrogen activation using Ru-catalyzed Murai reaction
Zuleta, Ernesto C.,Bozell, Joseph J.
supporting information, (2021/10/05)
In this study, we have assessed directed carbon-hydrogen activation (CHA) for alkylation of monomeric, dimeric, and polymeric lignin models using Murai's catalyst [RuH2(CO)(PPh3)3]. Based on related work from our laboratory showing that isolated organosolv lignin bears benzylic directing groups ideal for CHA reactions, this approach could offer new methodology for the valorization of biorefinery lignin. Monomeric and dimeric models bearing a keto group at the benzylic position undergo Ru-catalyzed alkylation in good to excellent yield. Similarly, models bearing a benzylic OH group also undergo alkylation via a tandem oxidation/alkylation process enabled by the Ru catalyst. Polymeric models show low levels of functionalization as a result of the poor solubility of the starting polymer. With unsymmetrical models, functionalization occurs first at the least sterically hindered ortho-site, but a subsequent alkylation, leading to disubstituted products can occur at the more sterically hindered site, leading to hexasubstituted arenes. The reaction shows sensitivity to free phenolic OH groups, which appears to reduce the yield in some reactions, and is also a contributing factor to the low yields observed with polymeric lignin models. Combining CHA methodology with lignin isolation technology able to introduce appropriate directing groups for catalytic functionalization will form the basis for improved conversion of lignin to high value chemical products.
C-C bond formation via C-H bond activation using an in situ-generated ruthenium catalyst
Martinez, Remi,Simon, Marc-Olivier,Chevalier, Reynald,Pautigny, Cyrielle,Genet, Jean-Pierre,Darses, Sylvain
supporting information; experimental part, p. 7887 - 7895 (2009/10/17)
We report here our full results concerning the possibility of generatingin situ from a stable and readily available ruthenium(II) source a high ly active ruthenium catalyst for C-H bond activation. The versatility ofthis catalytic system has been demonstrated, as it offers the possibili ty of modifying the electronic and steric properties of the catalyst by fine-tuning of the ligands, allowing functionalization of various substrates. Aromatic ketones and imines could be easily functionalized by the reaction with either vinylsilanes or styrenes, depending on the electronic and steric nature of the ligand. Moreover, variable-temperature NMR experiments and the isolation of a ruthenium intermediate complex provided some insights into the generation of the active catalytic ruthenium species in this reaction.
