Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Cover Picture: Fluorous Synthesis of 18F Radiotracers with the [18F]Fluoride Ion: Nucleophilic Fluorination as the Detagging Process (Angew. Chem. Int. Ed. 3/2009)
Time is of the essence in preparing 18F-labeled radiotracers when the half-life of 18F is 109.7 minutes. In their Communication on page 586, V. Gouverneur and co-workers report the radiosynthesis of various prosthetic groups and 18F radiotracers from fluorous-tagged precursors. This approach allows for fast and convenient purification of 18F-radiolabeled material (FSPE=fluorous solid phase extraction). Cover illustration produced by Dr. Karl Harrison (Chemistry Department, University of Oxford).
Also of Interest
Aqueous Olefin Metathesis
K. Grela and D. Burtscher review developments in aqueous olefin metathesis in their Minireview on p. 442. They focus on methods for synthesis “on water” and the targeted design of polar ruthenium catalysts which are stable and active in aqueous media.
A nonlinear effect is observed in asymmetric catalysis when the enantiomeric excess of the reaction product is not proportional to that of the chiral auxiliary or ligand. The consequences for the reaction mechanism are described by H. B. Kagan et al. in their Review on page 456.
Chemistry on Solid Support
Wada et al. describe in their Communiation on p. 496. the first stereocontrolled synthesis of oligonucleoside H-phosphonates. These compounds can be converted into multiple analogues through stereospecific modification at the phosphorous center.