<p>In this preprint, we present our initial results
concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and
alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline
directing group. Efficient C–H alkenylation was
achieved with a wide range of vinyl iodides bearing different aliphatic,
aromatic and heteroaromatic substituents, to furnish the corresponding C3
alkenylated products in good to high yields. In addition, we were able show
that this protocol can also be used to install an alkynyl group into the pyrrolidine
scaffold, when a TIPS-protected alkynyl bromide was used as the reaction
partner. Furthermore, two different methods for the removal of the 8-aminoquinoline
auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured
carboxylic acid building blocks from the C–H alkenylation products.</p>
Palladium-Catalyzed Multiple S-Arylation for the Synthesis of Macrocyclic Peptides
