Synthesis of Dihydrophosphaisocoumarins through a Palladium‐Catalyzed Oxidative Cyclization of Arylphosphonic Acid Monoethyl Esters with 1,3‐Dienes

An efficient synthetic method for the selective preparation of dihydrophosphaisocoumarins and their derivatives was developed through a palladium-catalyzed oxidative cyclization reaction of a wide range of arylphosphonic acid monoethyl esters with activated and unactivated 1,3-dienes, including 1-aryl-substituted 1,3-dienes and 1-alkyl-substituted 1,3-dienes, thus opening a new avenue for the synthesis of phosphaheterocyclic compounds.