Synthesis of Oxa‐ and Azapalladacycles from Organostannanes

An intramolecular Pd–C coupling reaction yields the oxapalladacycle 1. This is the first time that the transmetalation intermediate in the Stille coupling reaction has been isolated. Complexes of type 1 react readily with alkyl, allyl, benzyl, and acyl halides to form aryl-carbon bonds. This reaction can be extended to the preparation of substituted derivatives of 1 and the aza analogue 2.