查看文章

Alkynes are recurring structural motifs in a variety of natural products, bioactive molecules, and functional materials.[1] Among the many methods for the synthesis of substituted alkynes, the transition-metal-catalyzed Sonogashira coupling has proven to be one of the most popular and efficient.[2] While early studies focused on canonical C (sp) ÀC (sp2) bond formation, recent attention has been paid to the C (sp) ÀC (sp3) coupling of terminal alkynes with non-activated alkyl electrophiles. In a pioneering study Fu et al. discovered that N-heterocyclic carbene ligands could promote palladium-catalyzed Sonogashira coupling of primary alkyl bromides and iodides.[3] Later on Glorius and co-workers extended the work of Fu to even more challenging substrates, that is, nonactivated secondary alkyl halides.[4] The work of the group of Glorius represents an extraordinary example in palladium chemistry, because palladium …