An efficient method for the Heck-Catellani reaction of aryl halides.

We describe herein a new method that allows selective production of Catellani-Heck isomers from various aryl halides, including ones without ortho-groups. Under previous conditions, unhindered aryl halides were plagued with the formation of simple Heck isomers and multiple arylation and norbornene insertion. The use of a bulky PtBu3 ligand accelerates C-C reductive elimination from the key palladacycle.