The arylation of chroman-4-one and 4-hydroxycoumarin derivatives by pentavalent arylbismuth reagents has been carried out. Chroman-4-one gives the 3-diphenyl derivative, whereas 3-formyl and 3-oxalyl derivatives are phenylated to isoflavanones in moderate to high yields. Arylation of 4-hydroxycoumarins by various Bi (V) reagents gives rise to functionally substituted 3-aryl-4-hydroxycoumarins in high yields.
