Rhodium(II)-Catalyzed Aryl C−H Carboxylation of 2-Pyridylphenols with CO<sub>2</sub>
作者:Zhihua Cai、Shangda Li、Yuzhen Gao、Gang Li
DOI:10.1002/adsc.201800611
日期:2018.10.18
A protocol for C−H carboxylation of electron‐deficient 2‐pyridylphenols with CO2 through a Rh(II)‐catalyzed C−H bond activation under redox‐neutral conditions has been developed. A suitable phosphine ligand was crucial for this reaction. This method provided, in generally high yields, an access to a class of pyrido‐coumarins that are key structural motifs in biologically important molecules. Facile
Compounds and methods of preparing compounds represented by structural formula (I):
wherein X represents any suitable counter-anion;
R1 and R2 independently represent hydrogen, C1-6 alkoxy or nitro;
R3, R4, R5 and R6 each independently represents hydrogen, hydroxy, halo, C1-6 alkyl,
C2-6 alkenyl or C1-6 alkoxy; and
R7, R8, R9 and R10 each independently represents hydrogen, hydroxy, halo, C1-6 alkyl, C2-6 alkenyl or C1-6 alkoxy.
Compounds represented by structural formula (I) are useful in treating or preventing free radical-associated diseases or conditions in mammals.