6A Chemical Reviews, 2000, Vol. 100, No. 6
In Color on the Front Cover (Top left) Cleavage of methyl red from a single bead. See “Linkers and Cleavage Strategies in Solid-Phase Organic Synthesis and Combinatorial Chemistry” by Fabrice Guillier, David Orain, and Mark Bradley, p 2091. (Bottom left and right) Studies by Ludwig Claisen (1851−1930) on oxymethylene compounds laid the foundations of what became later known as vinylogy. Claisen’s investigations in this area were initiated in Munich 1887 and first reported in 1894 (Justus Liebigs Ann. Chem. 1894, 281, 306−313; Reprinted with permission. Copyright 1936 (photograph of Ludwig Claisen) and 1894 (copy of the first page of the article) Wiley-VCH.). As depicted in the scheme, the vinylogy concept did not go unnoticed in nature. Two articles in this issue deal with this subject. See “The Vinylogous Aldol Reaction: A Valuable, Yet Understated Carbon−Carbon Bond-Forming Maneuver” by Giovanni Casiraghi, Franca Zanardi, Giovanni Appendino, and Gloria Rassu, p 1929, and “Acylvinyl and Vinylogous Synthons” Rafael Chinchilla and Carmen Na´jera, p 1891. In Color on the Back Cover (Middle left) The cover picture shows the Mexican-hat-type potential energy surface of gold trifluoride, AuF3. See “Molecular Structure of Metal Halides” by Magdolna Hargittai, p 2233. (Bottom left) Equilibrium between free and bound water in micelles and reverse micelles in water. See “Dielectric Relaxation and Solvation Dynamics of Water in Complex Chemical and Biological Systems” by Nilashis Nandi, Kankan Bhattacharyya, and Biman Bagchi, p 2013. (Top right) Atomic force microscopy image of a (111) face of a ferritin crystal recorded in situ during growth from a solution with supersaturation C/Ceq ) 43, where C is the protein concentration and Ceq is the solubility. The image width is 9.5 µm (Reprinted with permission from ref 83). See “Dynamics of Layer Growth in Protein Crystallizations” by Peter G. Vekilov and J. Iwan D. Alexander, p 2061. (Second row right) View of MFI structure with modifying Ga species. See “Incorporation of Gallium into Zeolites: Syntheses, Properties, and Catalytic Application” by Rolf Fricke, Hendrik Kosslick, Gu¨nter Lischke, and Manfred Richter, p 2303. (Fourth row right) X-ray crystal structure of the ionomycin thallium complex (Reprinted with permission from Sakurai, T.; Kobayashi, K.; Nakamura, G.; Isono, K. Acta Crystallogr., Sect. B 1982, 38, 2471.). See “Strategy and Methodology Development for the Total Synthesis of Polyether Ionophore Antibiotics” by Margaret M. Faul and Bret E. Huff, p 2407. (Bottom right) Nitrogen-containing ligands for asymmetric catalysis. See “Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis” by Fabienne Fache, Emmanuelle Schulz, M. Lorraine Tommasino, and Marc Lemaire, p 2159.