Angewandte Chemie International Edition

Cover image for Vol. 51 Issue 39

September 24, 2012

Volume 51, Issue 39

Pages 9701–9940

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Editorial
    4. Graphical Abstract
    5. Flashback
    6. News
    7. Author Profile
    8. News
    9. Book Review
    10. Highlights
    11. Minireview
    12. Review
    13. Communications
    1. You have free access to this content
      Cover Picture: Magnesium Borohydride: From Hydrogen Storage to Magnesium Battery (Angew. Chem. Int. Ed. 39/2012) (page 9701)

      Dr. Rana Mohtadi, Dr. Masaki Matsui, Dr. Timothy S. Arthur and Dr. Son-Jong Hwang

      Article first published online: 11 SEP 2012 | DOI: 10.1002/anie.201206771

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      Reversible electrochemical magnesium deposition and stripping from a Mg(BH4)2 electrolyte is reported by R. Mohtadi and co-workers in their Communication on page 9780 ff. High coulombic efficiency of up to 94 % was achieved. This Mg(BH4)2 electrolyte was used in the first rechargeable magnesium battery utilizing a borohydride.

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      Inside Cover: Hexaphyrin Fused to Two Anthracenes (Angew. Chem. Int. Ed. 39/2012) (page 9702)

      Koji Naoda, Hirotaka Mori, Dr. Naoki Aratani, Byung Sun Lee, Prof. Dr. Dongho Kim and Prof. Dr. Atsuhiro Osuka

      Article first published online: 7 SEP 2012 | DOI: 10.1002/anie.201206773

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      π-Expanded porphyrinoids, in which aromatic units are fused to the porphyrin ring, have become the focus of recent attention. In their Communication on page 9856 ff., D. Kim, A. Osuka, et al. report the formation of a hexaphyrin fused to two anthracenes by an oxidative fusion reaction. Owing to the flat and elongated rectangular conjugated network, this fused hexaphyrin exhibits a remarkably red-shifted and unusual, sharp Q-band-like band at 1467nm. (The photos are courtesy of kyoto-design.jp.)

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      Inside Back Cover: Magnesium Nanocrystals Embedded in a Metal–Organic Framework: Hybrid Hydrogen Storage with Synergistic Effect on Physi- and Chemisorption (Angew. Chem. Int. Ed. 39/2012) (page 9941)

      Dae-Woon Lim, Dr. Ji Woong Yoon, Keun Yong Ryu and Prof. Myunghyun Paik Suh

      Article first published online: 11 SEP 2012 | DOI: 10.1002/anie.201206983

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      Hexagonal-disk-shaped Mg NCs (magnesium nanocrystals) have been fabricated within a porous MOF (metal–organic framework). In their Communication on page 9814 ff, M. P. Suh et al. report on the adsorption of hydrogen gas by Mg NCs@MOF both by physi- and chemisorption. Compared to pristine MOF, Mg NCs@MOF increases isosteric heat and uptake capacities of H2 physisorption, and decreases chemisorption/desorption temperatures by 200 K compared to bare Mg powder.

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      Back Cover: Two Interconvertible Structures that Explain the Spectroscopic Properties of the Oxygen-Evolving Complex of Photosystem II in the S2 State (Angew. Chem. Int. Ed. 39/2012) (page 9942)

      Dr. Dimitrios A. Pantazis, Dr. William Ames, Dr. Nicholas Cox, Prof. Dr. Wolfgang Lubitz and Prof. Dr. Frank Neese

      Article first published online: 7 SEP 2012 | DOI: 10.1002/anie.201206873

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      The structural flexibility of water oxidase is demonstrated by a combination of quantum chemistry and spectroscopy. In their Communication on page 9935 ff., D. A. Pantazis, F. Neese et al. show that the core of the photosynthetic oxygen-evolving complex exists in two interconvertible structures with distinct spectroscopic properties. This solves the puzzle of the two interconvertible signals in the S2 oxidation state of the catalyst, and paves the way for a deeper understanding of its function.

  2. Editorial

    1. Top of page
    2. Cover Pictures
    3. Editorial
    4. Graphical Abstract
    5. Flashback
    6. News
    7. Author Profile
    8. News
    9. Book Review
    10. Highlights
    11. Minireview
    12. Review
    13. Communications
    1. You have free access to this content
  3. Graphical Abstract

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    3. Editorial
    4. Graphical Abstract
    5. Flashback
    6. News
    7. Author Profile
    8. News
    9. Book Review
    10. Highlights
    11. Minireview
    12. Review
    13. Communications
    1. Graphical Abstract: Angew. Chem. Int. Ed. 39/2012 (pages 9709–9721)

      Article first published online: 19 SEP 2012 | DOI: 10.1002/anie.201290068

  4. Flashback

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    1. 50 Years Ago... (page 9718)

      Article first published online: 19 SEP 2012 | DOI: 10.1002/anie.201206190

      Angewandte Chemie International Edition was first published in 1962, the mother journal first in 1888. In this monthly flashback, we feature some of the articles that appeared 50 years ago. This look back can open our eyes, stimulate discussion, or even raise a smile.

  5. News

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    5. Flashback
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    9. Book Review
    10. Highlights
    11. Minireview
    12. Review
    13. Communications
  6. Author Profile

    1. Top of page
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    3. Editorial
    4. Graphical Abstract
    5. Flashback
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    7. Author Profile
    8. News
    9. Book Review
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    13. Communications
    1. Dietmar Stalke (pages 9730–9731)

      Article first published online: 13 JUN 2012 | DOI: 10.1002/anie.201202478

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      “If I were not a scientist, I would be a carpenter or a goldsmith. My favorite food is the Bratwurst at the Göttingen Christmas market …” This and more about Dietmar Stalke can be found on page 9730.

  7. News

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    12. Review
    13. Communications
  8. Book Review

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    13. Communications
    1. Nanotechnology. An Introduction. By Jeremy J. Ramsden. (page 9733)

      Thomas Schimmel

      Article first published online: 19 SEP 2012 | DOI: 10.1002/anie.201206358

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      Elsevier, Amsterdam, 2011. 288 pp., hardcover, € 71.95.—ISBN 978-0080964478

  9. Highlights

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    13. Communications
    1. Organocatalysis

      Asymmetric Synthesis of Cyclobutanes by a Formal [2+2] Cycloaddition Controlled by Dienamine Catalysis (pages 9734–9736)

      Dr. Alejandro Parra, Dr. Silvia Reboredo and Dr. José Alemán

      Article first published online: 22 AUG 2012 | DOI: 10.1002/anie.201203489

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      Trap it: A combination of aminocatalysis with H-bonding activation is used in two new approaches to carry out formal enantioselective organocatalyzed [2+2] cycloaddition reactions. This cooperative catalysis solves the inconveniences associated with this transformation. These two new reactions will open opportunities to find reactivities involving other organocatalytic cycloadditions.

    2. Conducting Materials

      Can We Understand the Molecule in Molecular Electronics? (pages 9737–9738)

      Prof. Steven L. Bernasek

      Article first published online: 15 AUG 2012 | DOI: 10.1002/anie.201204516

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      Using molecules as individual components in electronic devices promises the ultimate in miniaturization coupled with the flexibility of organic synthesis to tune the individual component. Examination of metal/molecule/metal junctions (see figure) show that organic functionality has little effect on the conductivity and rectification behavior of molecular electronic junctions, thus questioning the possible tunability of molecular electronic devices.

  10. Minireview

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    1. Water Chemistry

      Mononuclear Water Oxidation Catalysts (pages 9740–9747)

      Dr. Dennis G. H. Hetterscheid and Prof. Dr. Joost N. H. Reek

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201202948

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      One is enough: Mononuclear water oxidation catalysts are noteworthy as they can achieve turnover frequencies similar to those of the oxygen-evolving center of Photosystem II. Several of these mononuclear catalysts are highlighted, as well as studies on their incorporation into a device that splits water upon irradiation with visible light (see scheme)—an important first step towards efficient solar energy to fuel conversion.

  11. Review

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    1. Asymmetric Organocatalysis

      Cinchona-based Primary Amine Catalysis in the Asymmetric Functionalization of Carbonyl Compounds (pages 9748–9770)

      Prof. Dr. Paolo Melchiorre

      Article first published online: 15 AUG 2012 | DOI: 10.1002/anie.201109036

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      Primary choice: In only five years, cinchona-based primary amine catalysis has almost equaled the high level of efficiency and reliability of aminocatalysis by proline-derived catalysts, offering the unique possibility of effecting reactions between sterically demanding carbonyl compounds (see picture).

  12. Communications

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    1. Molecular Receptors

      99TcO4: Selective Recognition and Trapping in Aqueous Solution (pages 9772–9776)

      Prof. Roger Alberto, Dr. Greta Bergamaschi, Dr. Henrik Braband, Dr. Thomas Fox and Dr. Valeria Amendola

      Article first published online: 15 AUG 2012 | DOI: 10.1002/anie.201205313

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      Too hot to handle: Unprecedented affinity and specificity for 99TcO4 in aqueous solution was shown with the p-xylyl azacryptand in the hexaprotonated form (see scheme). A crystal structure of the complex reveals how the anion fits within the cavity of the cage, and the formation of multiple H-bond interactions with protonated amino groups stabilize the adduct.

    2. Cluster Compounds

      Synthesis of Gold–Silver Luminescent Honeycomb Aggregates by Both Solvent-Based and Solvent-Free Methods (pages 9777–9779)

      Dr. M. Carmen Blanco, Dr. Jéssica Cámara, Prof. Dr. M. Concepción Gimeno, Prof. Dr. Antonio Laguna, Prof. Stuart L. James, Dr. M. Cristina Lagunas and Dr. M. Dolores Villacampa

      Article first published online: 24 AUG 2012 | DOI: 10.1002/anie.201204859

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      Heterometallic clusters with strong luminescence have been synthesized (see picture: Au(C[TRIPLE BOND]CPh)2 yellow-red, Ag2 blue, O red) from the metalloligand unit [Au(C[TRIPLE BOND]CPh)PPh3] (yellow/red bars) by using both standard solvent-based and solvent-free reactions. The aggregates are stabilized only by acetylide–metal or metal–metal interactions, and their nuclearity is controlled through the addition of different donor ligands.

    3. Electrochemistry

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      Magnesium Borohydride: From Hydrogen Storage to Magnesium Battery (pages 9780–9783)

      Dr. Rana Mohtadi, Dr. Masaki Matsui, Dr. Timothy S. Arthur and Dr. Son-Jong Hwang

      Article first published online: 21 AUG 2012 | DOI: 10.1002/anie.201204913

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      Beyond hydrogen storage: The first example of reversible magnesium deposition/stripping onto/from an inorganic salt was seen for a magnesium borohydride electrolyte. High coulombic efficiency of up to 94 % was achieved in dimethoxyethane solvent. This Mg(BH4)2 electrolyte was utilized in a rechargeable magnesium battery.

    4. Hypergolicity

      Graphene and Graphene Oxide Can “Lubricate” Ionic Liquids based on Specific Surface Interactions Leading to Improved Low-Temperature Hypergolic Performance (pages 9784–9787)

      Parker D. McCrary, Preston A. Beasley, Spencer A. Alaniz, Chris S. Griggs, Dr. Rachel M. Frazier and Prof. Dr. Robin D. Rogers

      Article first published online: 5 SEP 2012 | DOI: 10.1002/anie.201205126

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      Space-qualified lubricants: Graphene and graphene oxide (r-GO) can strongly improve the low-temperature performance of hypergolic ionic liquids by reduction of viscosity. Key to success is to match the graphene type to the specific ionic-liquid functionality.

    5. Biosynthesis

      Regio- and Stereoselective Oxidative Phenol Coupling in Aspergillus niger (pages 9788–9791)

      Dr. Christian Gil Girol, Dr. Katja M. Fisch, Dr. Thorsten Heinekamp, Jun.-Prof. Dr. Stefan Günther, Dr. Wolfgang Hüttel, Prof. Dr. Jörn Piel, Prof. Dr. Axel A. Brakhage and Prof. Dr. Michael Müller

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201203603

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      Piecing it together: Aspergillus niger produces kotanin (see structure) by dimerization of the monomeric, polyketide-synthase-derived (PKS) 7-demethylsiderin. A combined approach, comprising bioinformatics and gene-deletion experiments, identified the biosynthetic cluster responsible for kotanin production. Homology modeling and substrate docking provide a rationale for the regio- and stereoselective phenol coupling reaction.

    6. Carbon Dioxide Reduction

      An Organic Hydride Transfer Reaction of a Ruthenium NAD Model Complex Leading to Carbon Dioxide Reduction (pages 9792–9795)

      Dr. Hideki Ohtsu and Prof. Koji Tanaka

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201204348

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      Ruthenium will fix it: CO2 undergoes reduction to HCO2 when placed over a solution of a ruthenium complex bearing an NADH model ligand 1 (black in right structural formula). The organic hydride transfer is triggered by the addition of benzoate anion, which rapidly forms a complex with 1, a complex that is a stronger reductant than 1. A photocatalytic variant of the reaction using triethanolamine as a sacrificial reagent has also been developed.

    7. Imaging Agents

      Metal Carbonyl–Gold Nanoparticle Conjugates for Live-Cell SERS Imaging (pages 9796–9799)

      Dr. Kien Voon Kong, Zhiyong Lam, Wenda Douglas Goh, Prof. Weng Kee Leong and Prof. Malini Olivo

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201204349

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      Conjugates of organometallic osmium carbonyl clusters and gold nanoparticles (see picture) show a strong carbonyl signal in surface-enhanced Raman spectroscopy. The ease of bio-functionalization and the high stability and good dispersibility in aqueous solution make these conjugates excellent candidates for biomedical applications, as demonstrated by live-cell imaging with the carbonyl signals of OM-NP(PEG)-L conjugates.

    8. mRNA splicing

      An RNA Splicing Enhancer that Does Not Act by Looping (pages 9800–9803)

      Helen Lewis, Andrew J. Perrett, Dr. Glenn A. Burley and Prof. Dr. Ian C. Eperon

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201202932

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      Out of the loop: Do the proteins bound to an enhancer site on pre-mRNA interact directly with the splice site by diffusion (looping), as is generally accepted, or does the intervening RNA play a role (see scheme)? By inserting a PEG linker between an enhancer sequence and alternative splice sites, the interaction of these two elements can be studied. Intervening RNA was essential for the enhancer activity, which rules out the looping model.

    9. CO2 Capture

      Low-Energy Selective Capture of Carbon Dioxide by a Pre-designed Elastic Single-Molecule Trap (pages 9804–9808)

      Dr. Mario Wriedt, Julian P. Sculley, Andrey A. Yakovenko, Dr. Yuguang Ma, Dr. Gregory J. Halder, Prof. Dr. Perla B. Balbuena and Prof. Dr. Hong-Cai Zhou

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201202992

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      Single-molecule trap: Easy activation of the water-stable metal–organic framework PCN-200 provides a new route to low-energy selective CO2 capture through stimuli-responsive adsorption behavior. This elastic CO2 trapping effect was confirmed by single-component and binary gas-adsorption isotherms and crystallographic determination.

    10. Flexible Materials

      Soft Janus Colloidal Crystal Film (pages 9809–9813)

      Dr. Syuji Fujii, Dr. Michael Kappl, Prof. Dr. Hans-Jürgen Butt, Tatsuya Sugimoto and Prof. Dr. Yoshinobu Nakamura

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201204358

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      Two-faced character in a film: Soft “Janus” two-dimensional colloidal crystal films were made using polystyrene (PS) particles, on an air–water interface as a mold for a flexible polypyrrole layer. By removing the PS particles, an array of femtoliter-sized cups was produced. These two-dimensional colloidal crystal films can also be transferred onto substrates with curvature.

    11. Hydrogen Storage

      Magnesium Nanocrystals Embedded in a Metal–Organic Framework: Hybrid Hydrogen Storage with Synergistic Effect on Physi- and Chemisorption (pages 9814–9817)

      Dae-Woon Lim, Dr. Ji Woong Yoon, Keun Yong Ryu and Prof. Myunghyun Paik Suh

      Article first published online: 7 SEP 2012 | DOI: 10.1002/anie.201206055

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      Hexagonal-disk-shaped magnesium nanocrystals (Mg NCs) are fabricated within a porous metal–organic framework (MOF, see picture). The Mg NCs@MOF stores hydrogen by both physi- and chemisorptions, exhibiting synergistic effects to decrease the isosteric heat of H2 physisorption compared with that of pristine MOF, and decrease the H2 chemisorption/desorption temperatures by 200 K compared with those of bare Mg powder.

    12. Near-Infrared Imaging

      In Vivo Fluorescence Imaging with Ag2S Quantum Dots in the Second Near-Infrared Region (pages 9818–9821)

      Guosong Hong, Dr. Joshua T. Robinson, Yejun Zhang, Shuo Diao, Alexander L. Antaris, Prof. Qiangbin Wang and Prof. Hongjie Dai

      Article first published online: 5 SEP 2012 | DOI: 10.1002/anie.201206059

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      Hits the dot: Ag2S quantum dots (QDs) with bright near-infrared-II fluorescence emission (around 1200 nm) and six-arm branched PEG surface coating (see scheme) were synthesized for in vivo small-animal imaging. The 6PEG-Ag2S QDs afforded a tumor uptake of approximately 10 % injected dose/gram, owing to a long circulation half-life of approximately 4 h. Clearance of the injected 6PEG-Ag2S QDs occurs mainly through the biliary pathway in mice.

    13. Palladium Catalysis

      Activator-Free Olefin Oligomerization and Isomerization Reactions Catalyzed by an Air- and Water-Tolerant Wacker Oxidation Intermediate (pages 9822–9824)

      Matthew S. Winston, Paul F. Oblad, Dr. Jay A. Labinger and Prof. John E. Bercaw

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201206215

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      A bench-stable, hydroxy-bridged α-diimine-Pd dimer can self-activate to an olefin oligomerization and isomerization catalyst in the presence of substrate (see scheme). A cationic Pd-hydride is generated principally through a Wacker oxidation of olefin to ketone, and with C4+ olefins, lesser amounts of allylic C-H activation, β-H transfer, and release of diene products are observed.

    14. Natural Product Synthesis

      Total Synthesis of (−)-Jiadifenin (pages 9825–9828)

      Dr. Yang Yang, Dr. Xingnian Fu, Dr. Jianwei Chen and Prof. Dr. Hongbin Zhai

      Article first published online: 24 AUG 2012 | DOI: 10.1002/anie.201203176

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      As easy as ABCD: (−)-Jiadifenin was synthesized in eighteen reaction steps from 1-[(E)-(4′-bromo-2′-butenyl)oxy]-4-methoxybenzene. Key features of this synthesis include: 1) Ireland–Claisen rearrangement to produce the two contiguous quaternary centers at C5 and C6 simultaneously, 2) intramolecular Pauson–Khand reaction (IMPKR) to concurrently construct the A and B rings, and 3) [2+2] photo-cycloaddition to generate the all-carbon quaternary center at C9.

    15. Cascade Catalysis

      Synthesis of Tetrahydropyridazines by a Metal–Carbene-Directed Enantioselective Vinylogous N[BOND]H Insertion/Lewis Acid-Catalyzed Diastereoselective Mannich Addition (pages 9829–9833)

      Dr. Xinfang Xu, Dr. Peter Y. Zavalij and Prof. Michael P. Doyle

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201203962

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      A versatile cascade of reactions, triggered by RhII-catalyzed diazo decomposition followed by a vinylogous N[BOND]H insertion/Lewis acid catalyzed Mannich addition, that produces highly substituted 1,2,3,6-tetrahydropyridazines in up to 97 % ee with high yield and diastereocontrol has been developed.

    16. Hydrostannylation

      Studies on the Mechanism of B(C6F5)3-Catalyzed Hydrostannylation of Propargylic Alcohol Derivatives (pages 9834–9837)

      Martins S. Oderinde and Prof. Michael G. Organ

      Article first published online: 24 AUG 2012 | DOI: 10.1002/anie.201204060

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      Sleight of hydride: B(C6F5)3 catalyzes the hydrostannylation of propargylic alcohols in a regio- and stereoselective manner (see scheme). This Lewis acid first abstracts a hydride from the stannane, thus forming a borohydride/stannyl cation pair, the stability of which depends on solvent and ligands. Deuterium-labeling experiments showed that the source that delivers a hydride to the alkenyl cation is not the borohydride but rather a second molecule of stannane.

    17. Metallacycles

      Synthesis and Characterization of a Metallapyridyne Complex (pages 9838–9841)

      Tongdao Wang, Dr. Hong Zhang, Feifei Han, Dr. Ran Lin, Prof. Dr. Zhenyang Lin and Prof. Dr. Haiping Xia

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201204073

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      Building bridges: The first m-metallapyridine and the first metallapyridyne were synthesized under mild reaction conditions (see scheme). The two complexes are metal-bridged polycyclic metallabenzenoid aromatics, in which the transition-metal center is shared by both six-membered rings. The synthetic method permits the use of metallabenzene as a starting material to access higher π-electron metallaaromatics.

    18. Enantioselective Synthesis

      Enantioselective Synthesis and Stereoselective Ring Opening of N-Acylaziridines (pages 9842–9845)

      Jennifer Cockrell, Christopher Wilhelmsen, Heather Rubin, Allen Martin and Prof. Jeremy B. Morgan

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201204224

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      Kinetic resolution of N-acylaziridines by nucleophilic ring opening was achieved with (R)-BINOL as the chiral modifier under boron-catalyzed conditions (see scheme; Ar=3,5-dinitrophenyl). The consumed enantiomer of aziridine can be further converted to an enantioenriched 1,2-chloroamide with recovery of (R)-BINOL.

    19. Domino Reactions

      Expeditious Synthesis of Tetrasubstituted Helical Alkenes by a Cascade of Palladium-Catalyzed C[BOND]H Activations (pages 9846–9850)

      Dr. Hongqiang Liu, Mohamed El-Salfiti and Prof. Dr. Mark Lautens

      Article first published online: 24 AUG 2012 | DOI: 10.1002/anie.201204226

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      Twisted molecules: A modular approach for the synthesis of tetrasubstituted helical alkenes by a palladium-catalyzed norbornene-mediated domino reaction is presented. This intermolecular domino process allows the formation of three C[BOND]C bonds in one operation through a C[BOND]H activation/carbopalladation/C[BOND]H activation sequence.

    20. Synthetic Methods

      Reductive Cleavage of the Cmath image[BOND]Cmath image Bond of Secondary Benzyl Alcohols: Rhodium Catalysis Directed by N-Containing Groups (pages 9851–9855)

      Kang Chen, Hu Li, Zhi-Quan Lei, Yang Li, Wen-He Ye, Li-Sheng Zhang, Prof. Jian Sun and Prof. Dr. Zhang-Jie Shi

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201204338

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      Cutting loose: 1,1-Biarylmethanol substrates undergo reductive cleavage of the C[BOND]C bond in the presence of a cationic RhIII catalyst and H2 (see scheme; DG=directing group). Various functional groups are tolerated in the reaction system. Preliminary studies indicate that a five-membered rhodacycle intermediate, which then converts into a RhIII hydride species for the reduction, is involved in the catalytic cycle.

    21. Porphyrinoids

      Hexaphyrin Fused to Two Anthracenes (pages 9856–9859)

      Koji Naoda, Hirotaka Mori, Dr. Naoki Aratani, Byung Sun Lee, Prof. Dr. Dongho Kim and Prof. Dr. Atsuhiro Osuka

      Article first published online: 2 AUG 2012 | DOI: 10.1002/anie.201204446

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      Gold standard: A bis(AuIII) complex containing the title compound was prepared and characterized (see scheme; DDQ=2,3-dichloro-5,6-dicyano-1,4-benzoquinone, Tf=trifluoromethanesulfonyl). Owing to the effective conjugative network over the flat and elongated rectangular molecular frame, this complex displays a remarkably red-shifted and sharp Q-band-like band at 1467 nm, multiple reversible redox potentials, and a large TPA cross-section value.

    22. Quantum Computer

      A Synthetic Two-Spin Quantum Bit: g-Engineered Exchange-Coupled Biradical Designed for Controlled-NOT Gate Operations (pages 9860–9864)

      Dr. Shigeaki Nakazawa, Dr. Shinsuke Nishida, Dr. Tomoaki Ise, Dr. Tomohiro Yoshino, Dr. Nobuyuki Mori, Dr. Robabeh D. Rahimi, Prof. Dr. Kazunobu Sato, Prof. Dr. Yasushi Morita, Dr. Kazuo Toyota, Prof. Dr. Daisuke Shiomi, Prof. Dr. Masahiro Kitagawa, Dr. Hideyuki Hara, Dr. Patrick Carl, Dr. Peter Höfer and Prof. Dr. Takeji Takui

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201204489

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      A quantum gate: A system of two coupled electron spins that is useful for simple quantum computing operations has been prepared by synthesis of a biradical 1 and co-crystallization with an isomorphous host molecule. The two weakly exchange-coupled quantum bits (target qubit blue and control qubit red) span four electron spin states. The electron spin transition is denoted by two black arrows.

    23. Photocatalysis

      Water Oxidation Using a Particulate BaZrO3-BaTaO2N Solid-Solution Photocatalyst That Operates under a Wide Range of Visible Light (pages 9865–9869)

      Prof. Dr. Kazuhiko Maeda and Prof. Dr. Kazunari Domen

      Article first published online: 5 SEP 2012 | DOI: 10.1002/anie.201204635

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      Tripping the light fantastic: Despite small band gap energies (1.7–1.8 eV), BaZrO3-BaTaO2N solid solutions (Zr/Ta≤0.1) are capable of photocatalyzing both water oxidation and reduction even under irradiation above 660 nm. Solar water splitting to form H2 and O2 was also demonstrated using a photoelectrochemical cell consisting of a BaZrO3–BaTaO2N solid solution as an anode and a Pt wire cathode.

    24. Carbohalogenation

      A Conjunctive Carboiodination: Indenes by a Double Carbopalladation–Reductive Elimination Domino Process (pages 9870–9872)

      Dr. Xiaodong Jia, David A. Petrone and Prof. Dr. Mark Lautens

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201204716

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      Something gained, nothing lost: A Pd0-catalyzed domino intermolecular/intramolecular process terminated by carbohalogenation is reported. In this reaction, two new C[BOND]C bonds, one new C[BOND]I bond and one five-membered ring are formed in a single step, and all of the atoms in the starting materials are incorporated into the product (see scheme).

    25. Organic Solar Cells

      Stable Dyes Containing Double Acceptors without COOH as Anchors for Highly Efficient Dye-Sensitized Solar Cells (pages 9873–9876)

      Jiangyi Mao, Nannan He, Dr. Zhijun Ning, Dr. Qiong Zhang, Fuling Guo, Long Chen, Dr. Wenjun Wu, Prof. Jianli Hua and Prof. He Tian

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201204948

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      The electron acceptor 2-(1,1-dicyanomethylene) rhodanine is a promising alternative to cyanoacrylic acid as an anchoring group for organic dyes. For example, the RD-II-based dye-sensitized solar cell has an overall conversion efficiency of 7.11 % and long-term stability.

    26. Natural Products

      Total Syntheses of Amphidinolides B, G, and H (pages 9877–9880)

      Akihiro Hara, Ryo Morimoto, Yuki Iwasaki, Dr. Tsuyoshi Saitoh, Dr. Yuichi Ishikawa and Prof. Dr. Shigeru Nishiyama

      Article first published online: 24 AUG 2012 | DOI: 10.1002/anie.201204992

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      Not one, not two, but three: Total syntheses of amphidinolides B, G, and H, which exhibit strong, nanogram-scale cytotoxicity against various tumor cell lines, have been executed. The synthetic strategy relied on implementation of a diene construction protocol and a diastereoselective aldol process. The 26- and 27-membered macrocyclic lactone rings were efficiently constructed by using ring-closing metathesis (RCM).

    27. Energetic Materials

      Tris(triazolo)benzene and Its Derivatives: High-Density Energetic Materials (pages 9881–9885)

      Dr. Venugopal Thottempudi, Dr. Farhad Forohor, Dr. Damon A. Parrish and Prof. Dr. Jean'ne M. Shreeve

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201205134

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      High-performance explosives: Tris(triazolo)benzene was synthesized and converted to its trinitro and trichloro derivatives (see scheme; R=NO2, Cl). The heats of formation of this “high-nitrogen” compounds were calculated and combined with experimentally determined densities to determine detonation pressures and velocities. They exhibit high density, good thermal stability, high heats of formation, and moderate to good detonation properties.

    28. Asymmetric Catalysis

      Synthesis of Enantiomerically Enriched Imidazolidin-2-Ones through Asymmetric Palladium-Catalyzed Alkene Carboamination Reactions (pages 9886–9890)

      Brett A. Hopkins and Prof. Dr. John P. Wolfe

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201205233

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      Positive water effect: A catalyst composed of [Pd2(dba)3] (dba=dibenzylideneacetone) and (S)-Siphos-PE is effective for the enantioselective coupling of N-allyl ureas with aryl bromides to afford 4-substituted imidazolidin-2-ones. Added water leads to significantly improved enantioselectivities with electron-poor aryl halide substrates. It is suggested that the C[BOND]C bond-forming reductive elimination is the enantiodetermining step in these reactions.

    29. Gold Catalysis

      One-Pot Gold-Catalyzed Synthesis of Azepino[1,2-a]indoles (pages 9891–9895)

      Gianpiero Cera, Stefano Piscitelli, Dr. Michel Chiarucci, Prof. Giancarlo Fabrizi, Dr. Antonella Goggiamani, Rubén S. Ramón, Prof. Dr. Steven P. Nolan and Prof. Marco Bandini

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201205463

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      Indoles from scratch: A gold(I)/N-heterocyclic carbene complex (IPr=1,3-di(isopropylphenyl)imidazol-2-ylidene) was found to be particularly effective as a catalyst, enabling the one-pot synthesis of tricyclic azepinoindoles by an unprecedented cascade reaction. Readily available substrates, high chemoselectivity, good yields, and water as the only stoichiometric by-product are some of the main advantages of this method.

    30. Solar Cells

      Efficient Dye-Sensitized Solar Cells Based on Hydroquinone/Benzoquinone as a Bioinspired Redox Couple (pages 9896–9899)

      Dr. Ming Cheng, Prof. Xichuan Yang, Dr. Fuguo Zhang, Dr. Jianghua Zhao and Prof. Licheng Sun

      Article first published online: 5 SEP 2012 | DOI: 10.1002/anie.201205529

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      A hybrid electrolyte involving tetramethylammonium (TMA) hydroquinone/benzoquinone redox couple is formulated. This electrolyte is more transparent than the traditional I/I3 electrolyte and has negligible absorption in the visible region. Dye-sensitized solar cells using the hybrid electrolyte show higher light-to-electricity conversion efficiency. FTO=fluorine-doped tin oxide.

    31. Silicates

      Aqueous Alkali-Metal Silicate Anions Containing Fully Condensed Four-Coordinate Sites (pages 9900–9903)

      Dr. Christopher T. G. Knight, Dr. Raymond J. Balec and Prof. Stephen D. Kinrade

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201205606

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      Conspicuous absence: 29Si NMR studies show that highly condensed, four-coordinate Si-containing anions are common in concentrated alkali-metal silicate solutions, but reveal no evidence for the existence of specialized zeolite building units. The results add to the mounting evidence that silicate polymerization simply proceeds through stepwise condensation of monosilicate tetrahedra.

    32. C[BOND]H Activation

      Rhodium-Catalyzed Direct C[BOND]H Amination of Benzamides with Aryl Azides: A Synthetic Route to Diarylamines (pages 9904–9908)

      Jaeyune Ryu, Kwangmin Shin, Sae Hume Park, Ji Young Kim and Prof. Dr. Sukbok Chang

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201205723

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      No muss, no fuss: A rhodium-catalyzed direct intermolecular C[BOND]H amination of benzamides and ketoximes using aryl azides as the amine source has been developed. The reaction exhibits a broad substrate scope with excellent functional-group tolerance, requires no external oxidants, releases N2 as the only by-product, and produces diarylamines in high yields.

    33. Cross-Coupling

      Nickel-Catalyzed Kumada Reaction of Tosylalkanes with Grignard Reagents to Produce Alkenes and Modified Arylketones (pages 9909–9913)

      Ji-Cheng Wu, Lu-Bing Gong, Dr. Yuanzhi Xia, Ren-Jie Song, Ye-Xiang Xie and Prof. Dr. Jin-Heng Li

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201205969

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      Open a new door: The first example of alkene synthesis from alkyl electrophiles with Grignard reagents using the Kumada cross-coupling reaction strategy is reported. This method opens a new door for the Kumada cross-coupling reaction, allowing alkenes to be prepared from the reaction of tosylalkanes with Grignard reagents.

    34. Enzyme Catalysis

      Enantioselective Oxidation of Aldehydes Catalyzed by Alcohol Dehydrogenase (pages 9914–9917)

      Dr. Paul Könst, Dr. Hedda Merkens, Dr. Selin Kara, Svenja Kochius, Dr. Andreas Vogel, Dr. Ralf Zuhse, Dr. Dirk Holtmann, Prof. Dr. Isabel W. C. E. Arends and Dr. Frank Hollmann

      Article first published online: 31 AUG 2012 | DOI: 10.1002/anie.201203219

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      Teaching old dogs new tricks: Alcohol dehydrogenases (ADHs) may be established redox biocatalysts but they still are good for a few surprises. ADHs can be used to oxidize aldehydes, and this was demonstrated by the oxidative dynamic kinetic resolution of profens. In the presence of a suitable cofactor regeneration system, this reaction can occur with high selectivity.

      Corrected by:

      Corrigendum: Corrigendum: Enantioselective Oxidation of Aldehydes Catalyzed by Alcohol Dehydrogenase

      Vol. 51, Issue 48, 11924, Article first published online: 21 NOV 2012

    35. Weak Interactions

      Discrete and Extended Supersandwich Structures Based on Weak Interactions between Phosphorus and Mercury (pages 9918–9921)

      Martin Fleischmann, Claudia Heindl, Michael Seidl, Dr. Gábor Balázs, Dr. Alexander V. Virovets, Dr. Eugenia V. Peresypkina, Mitsukimi Tsunoda, Dr. François P. Gabbaï and Prof. Dr. Manfred Scheer

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201204686

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      Supersized mercury: Adducts with polymeric (left) or discrete supersandwich structures (right) form from mixtures of the trinuclear mercury complex [(o-C6F4Hg)3] (A) with the triple-decker complex [(CpMo)2(μ-η66-P6)] (B) in the solid state. This arrangement arises from P⋅⋅⋅Hg interactions between opposing atoms of the P6 units and the Hg3 units (see picture; P purple, Hg orange, F green, Mo red, C gray).

    36. Lanthanide Anisotropy

      Differentiation of Highly Anisotropic TbIII and DyIII with 57Fe Mössbauer Spectroscopy (pages 9922–9925)

      Dr. Valeriu Mereacre

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201204838

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      Using 57Fe Mössbauer spectroscopy, three examples of coordination compounds with different topologies containing FeIII and LnIII ions (DyIII and TbIII; see diagram; insets: clusters cores) were analyzed. In the same crystal field environment, Dy and Tb ions show different degrees of anisotropy, which can be qualitatively detected using an indirect method.

    37. 1,2-Dimetallic Compounds

      InCl3-Catalyzed Synthesis of 1,2-Dimetallic Compounds by Direct Insertion of Aluminum or Zinc Powder (pages 9926–9930)

      Tobias D. Blümke, Thomas Klatt, Prof. Dr. Konrad Koszinowski and Prof. Dr. Paul Knochel

      Article first published online: 5 SEP 2012 | DOI: 10.1002/anie.201205169

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      In-sertion of metal: Catalytic amounts of InCl3 allow the insertion of aluminum and zinc into aromatic 1,2-dibromides or 1,2-bromotriflates (see scheme). These 1,2-dimetallic species can undergo Cu or Pd-catalyzed acylations, allylations, or cross-couplings.

    38. Diborenes

      Base-Stabilized Diborenes: Selective Generation and η2 Side-on Coordination to Silver(I) (pages 9931–9934)

      Dipl.-Chem. Philipp Bissinger, Prof. Dr. Holger Braunschweig, Dipl.-Chem. Alexander Damme, Dr. Thomas Kupfer and Dr. Alfredo Vargas

      Article first published online: 3 SEP 2012 | DOI: 10.1002/anie.201204449

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      (B)olefin complexes: Reductive coupling of designed monoborane precursors (see scheme; Dur=2,3,5,6-tetramethylphenyl) gives convenient access to N-heterocyclic carbene stabilized diborenes. The presence of B[BOND]B multiple bonds in the dark red diborenes is shown experimentally and theoretically. Reaction with AgCl afforded a AgI species with an unprecedented, olefin-like η2 coordination mode.

    39. Photosystem II

      Two Interconvertible Structures that Explain the Spectroscopic Properties of the Oxygen-Evolving Complex of Photosystem II in the S2 State (pages 9935–9940)

      Dr. Dimitrios A. Pantazis, Dr. William Ames, Dr. Nicholas Cox, Prof. Dr. Wolfgang Lubitz and Prof. Dr. Frank Neese

      Article first published online: 21 AUG 2012 | DOI: 10.1002/anie.201204705

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      Using models derived from the X-ray structure of photosystem II, it is shown that the oxygen evolving complex in the S2 state exists in two energetically similar and interconvertible forms. A longstanding question regarding the spectroscopy of the catalyst is thus answered: one form corresponds to the multiline g=2.0 EPR signal (see picture, right; O red, Mn purple, Ca yellow), and the other to the g≥4.1 signals (left).

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