Palladium-Catalyzed Alkynylation and Concomitant ortho Alkylation of Aryl Iodides

We report an efficient alkynylation reaction of aryl iodides with simultaneous ortho-alkylaton of aryl rings. The reaction between three simple reagents—aryl halides, alkynes, and alkyl halides—formed aryl–alkynyl bonds carrying hindered aryl rings in one step. The reaction proceeded via a Catellani-type pathway in the presence of norbornene. From a synthetic perspective, this reaction allows quick access toward many 1,2,3-substituted arenes and multiply substituted benzofurans, after manipulation of alkyne groups. These compounds are difficult to synthesize otherwise. MOE (Min. of Education, S’pore)