1841-56-1Relevant academic research and scientific papers
ortho-C?H Arylation of Benzoic Acids with Aryl Bromides and Chlorides Catalyzed by Ruthenium
Biafora, Agostino,Krause, Thilo,Hackenberger, Dagmar,Belitz, Florian,Goo?en, Lukas J.
supporting information, p. 14752 - 14755 (2016/11/23)
A system consisting of catalytic amounts of [(p-cym)RuCl2]2/PEt3?HBF4, K2CO3as the base, and NMP as the solvent efficiently mediates the ortho-C?H arylation of benzoic acids with aryl bromides at 100 °C. Replacing the phosphine ligand with the amino acid dl-pipecolinic acid enables the analogous transformation with aryl chlorides. The key advantage of this broadly applicable transformation is the use of an inexpensive ruthenium catalyst in combination with simple carboxylates as directing groups, which can either be tracelessly removed or used as anchor points for decarboxylative ipso substitutions.
Room-temperature cobalt-catalyzed arylation of aromatic acids: overriding the ortho-selectivity via the oxidative assembly of carboxylate and aryl titanate reagents using oxygen
Liu, Kun-Ming,Zhang, Rui,Duan, Xin-Fang
supporting information, p. 1593 - 1598 (2016/02/09)
A room temperature phosphine or NHC ligand-free cobalt-catalyzed arylation of (hetero)aromatic acids has been developed. It involves an oxidative cross-coupling between carboxylate and aryl titanate reagents using oxygen as an oxidant, and the arylation at the position ortho, meta and para to the carboxylic acid group could all be achieved. As application, various (hetero)aromatic acids including xenalipin, tafamidis and the key intermediate for a cardioprotective compound have been efficiently synthesized.
General and practical carboxyl-group-directed remote C-H oxygenation reactions of arenes
Wang, Yang,Gulevich, Anton V.,Gevorgyan, Vladimir
, p. 15836 - 15840 (2014/04/03)
Two methods for remote aromatic C-H oxygenation reactions, have been developed. Method1, the Cu-catalyzed oxygenation reaction, is highly efficient for cyclization of electron-neutral and electron-rich biaryl carboxylic acids into 3,4-benzocoumarins. Method2, the K2S2O 8-mediated oxygenation reaction, is more general and practical for cyclization of substrates with electron-donating and -withdrawing groups (see scheme). Copyright
