Karmel, Caleb published the artcileIridium-Catalyzed Silylation of C-H Bonds in Unactivated Arenes: A Sterically Encumbered Phenanthroline Ligand Accelerates Catalysis, Formula: C8H10O2, the main research area is phenanthroline ligand iridium catalyzed silylation unactivated arene.
We report a new system for the silylation of aryl C-H bonds. The combination of [Ir(cod)(OMe)]2 and 2,9-Me2-phenanthroline (2,9-Me2-phen) catalyzes the silylation of arenes at lower temperatures and with faster rates than those reported previously, when the hydrogen byproduct is removed, and with high functional group tolerance and regioselectivity. Inhibition of reactions by the H2 byproduct is shown to limit the silylation of aryl C-H bonds in the presence of the most active catalysts, thereby masking their high activity. Anal. of initial rates uncovered the high reactivity of the catalyst containing the sterically hindered 2,9-Me2-phen ligand but accompanying rapid inhibition by hydrogen. With this catalyst, under a flow of nitrogen to remove hydrogen, electron-rich arenes, including those containing sensitive functional groups, undergo silylation in high yield for the first time, and arenes that underwent silylation with prior catalysts react over much shorter times with lower catalyst loadings. The synthetic value of this methodol. is demonstrated by the preparation of key intermediates in the synthesis of medicinally important compounds in concise sequences comprising silylation and functionalization. Mechanistic studies demonstrate that the cleavage of the aryl C-H bond is reversible and that the higher rates observed with the 2,9-Me2-phen ligand are due to a more thermodynamically favorable oxidative addition of aryl C-H bonds.
Journal of the American Chemical Society published new progress about Benzenoid aromatic compounds Role: PEP (Physical, Engineering or Chemical Process), PRP (Properties), RCT (Reactant), SPN (Synthetic Preparation), PROC (Process), RACT (Reactant or Reagent), PREP (Preparation). 151-10-0 belongs to class isoquinoline, name is 1,3-Dimethoxybenzene, and the molecular formula is C8H10O2, Formula: C8H10O2.
Referemce:
Isoquinoline – Wikipedia,
Isoquinoline | C9H7N – PubChem