Cover Picture: “Bottom-Up” Embedding of the Jørgensen–Hayashi Catalyst into a Chiral Porous Polymer for Highly Efficient Heterogeneous Asymmetric Organocatalysis (Chem. Eur. J. 22/2012)
Article first published online: 23 MAY 2012
Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chemistry - A European Journal
Volume 18, Issue 22, page 6693, May 29, 2012
How to Cite
Wang, C. A., Zhang, Z. K., Yue, T., Sun, Y. L., Wang, L., Wang, W. D., Zhang, Y., Liu, C. and Wang, W. (2012), Cover Picture: “Bottom-Up” Embedding of the Jørgensen–Hayashi Catalyst into a Chiral Porous Polymer for Highly Efficient Heterogeneous Asymmetric Organocatalysis (Chem. Eur. J. 22/2012). Chem. Eur. J., 18: 6693. doi: 10.1002/chem.201290088
- Issue published online: 23 MAY 2012
- Article first published online: 23 MAY 2012
- asymmetric catalysis;
- heterogeneous catalysis;
- Michael addition;
- supported catalysts
Lewis base catalyzed cyclization reactions of allenoates with electron-deficient olefins and imines have been used to prepare biologically active natural products and pharmaceutically interesting substances and have emerged as powerful synthetic tools in the rapid construction of cyclic molecular complexity. In the Concept article on p. 6712 ff., M. Shi and C.-K. Pei summarize the recent progress in this emerging field and outline the challenges ahead.
Iridium complexes consisting of N,P-ligands are shown to be efficient catalysts for the hydrogenation of pinacol-derived boronic esters. Whereas a phosphinoimidazoline ligand is identified as highly efficient for the asymmetric hydrogenation of terminal vinyl boronic esters, trisubstituted bis- and monoboronates can be reduced with high activity and good to excellent selectivity employing a pyridine–phosphinite ligand. For more details see the Communication by A. Pfaltz and A. Ganić on page 6724 ff.
The copper-mediated Ullmann coupling of 1,7-dibromoperylene bisimides afforded structurally perfect singly-linked perylene bisimide (PBI) arrays, whereas the homocoupling of 1,12-dibromoperylene bisimides gave doubly-linked and triply-linked diperylene bisimides. The degree of interaction in the neutral and the reduced forms of bay-linked perylene bisimides, which differed in their linkage, was due to the different degrees of twisting and flexibility between the PBI moieties and was evidenced by experimental and computed results. For more details see the Full Paper by Z. Wang, C. Lambert, F. Negri et al. on page 6764 ff.