Palladium-Catalyzed Intermolecular Carbene Insertion Prior to Intramolecular Heck Cyclization: Synthesis of 2-Arylidene-3-aryl-1-indanones

A domino process that converges the migratory insertion of carbene with a Heck reaction has been established as a versatile tool for the synthesis of 2-arylidene-3-aryl-1-indanones from very stable and easily accessible N-tosylhydrazones and 2′-iodochalcones. The reaction selectively proceeds through 5-exo-trig cyclization and delivers the products selectively with the E configuration of the double bond in excellent yields. The one-pot synthesis of 2-arylidene-3-aryl-1-indanones involving in situ synthesis of both 2′-iodochalcones and N-tosylhydrazones has also been demonstrated.