The three-step one-pot α-arylation-annulation sequence leading to the reaction of 4-hydroxycoumarins with in situ generated 2-(bromomethyl)aryllead triacetates carried out in the presence of a combination of ortho-phenantroline-potassium tert-butoxide afforded tetracyclic benzo[b]pyran compounds in good to high yields.
4-hydroxycoumarins - arylboronic acids - aryllead triacetates - reductive ligand coupling reactions