Metal-free access to 3-allyl-2-alkoxychromanones <i>via</i> phosphine-catalyzed alkoxy allylation of chromones with MBH carbonates and alcohols
作者:Ling Meng、Xiaoyong Chang、Zhenyang Lin、Jun (Joelle) Wang
DOI:10.1039/d1ob00215e
日期:——
A phosphine-catalyzed alkoxy allylation of chromones with MBH carbonates and alcohols is established for the metal-free synthesis of 3-allyl-2-alkoxychromanones with high diastereoselectivity.
Pd-Catalyzed asymmetric decarboxylative cycloaddition of vinylethylene carbonates with 3-cyanochromones
作者:Ijaz Khan、Can Zhao、Yong Jian Zhang
DOI:10.1039/c8cc02456a
日期:——
of vinylethylene carbonates with 3-cyanochromones. By using a palladium complex generated in situ from [Pd2(dba)3]·CHCl3 and phosphoramidite L3 as a catalyst under mild reaction conditions, the process afforded furanobenzodihydropyrans bearing vicinal quaternary stereocenters in high yields with good to high enantio- and diastereoselectivities.
(3-Carboxy-5-oxo-5H[1]benzopyrano[2, 3-b]pyridin-2-yl)acetic acid derivatives (3 and 4) were found to possess potent antiarthritic activity in the rat adjuvant arthritis model. The mode of action of these compounds differs from that of acidic antiinflammatory drugs. Various modifications in these compounds (e.g., elongation, removal, or substitution of the methylene group of the acetic acid moiety; and substitution of the benzene ring) were made in order to study the structure-activity relationships. However, it was found that the structural requirements for the compounds to show activity are rather severe.