Tunable carbon–carbon and carbon–sulfur cross–coupling of boronic acids with thioamide fragments

ORGN 10

C. Oliver Kappe, oliver.kappe@uni-graz.at and Hana Prokopcova. Institute of Chemistry, Karl-Franzens-University of Graz, Heinrichstrasse 28, Graz, A-8010, Austria
We have developed a Pd(0)-catalyzed, Cu(I)-mediated cross coupling of boronic acids with cyclic thioamide or thiourea fragments under neutral conditions. These microwave-assisted transformations are related to the Liebeskind-Srogl reaction and provide carbon-carbon bond formation in a very efficient and rapid way. In the absence of Pd(0), carbon-sulfur cross coupling is observed. The mechanism of both processes will be discussed, and an application toward the synthesis Bay 41-4109, a highly potent non-nucelosidic inhibitor of hepatitis B virus replication, outlined.