Heterogeneous catalysis for organic synthesis under continuous‐flow conditions becomes possible by a new reactor‐based approach. Continuous‐flow reactors with a monolithic glass/polymer composite interior are loaded with palladium particles by ion exchange followed by reduction. When incorporated into a continuous‐flow setup (PASSflow) this reactor allows the transfer‐hydrogenation of alkenes, alkynes, nitro‐substituted aromatic compounds and benzyl ethers in the flow‐through mode. In addition, the activity of the catalysts is well suited to achieve Suzuki, Sonogashira and Heck cross‐coupling reactions in the absence of phosphanes or any other ligands, resulting in a greatly simplified purification. As an extension to this concept a bifunctional support was prepared inside the reactor consisting of Pd particles and an ion‐exchange group (hydroxide form). In the Suzuki− Miyaura reaction the reactor serves as a base for immobilisation and activation of the boronic acid as boronate and as a catalyst for promoting the C−C coupling reaction under continuous‐flow conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

No abstract

A novel synthesis of mappicine ketone, which possesses strong selective activity against the herpes viruses HSV-1 and HSV-2, including those Acyclovir-resistant, and human cytomegalovirus (HCMV) has been efficiently accomplished. The synthesis highlights a new pyridone approach that effectively combines a double, intramolecular Michael addition in a conjugated ester-conjugated amide with oxidation-decarboxylation of the resulting piperidone.