© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Volume 2, Issue 9
Xufeng Lin, Cunyuan Zhao, Chi-Ming Che, Zhuofeng Ke and David Lee Phillips
Version of Record online: 27 AUG 2007 | DOI: 10.1002/asia.200790025
Singlet or triplet? That is the question asked by C.-M. Che and co-workers for the way dirhodium tetracarboxylates catalyze intramolecular CH bond amidation. These reactions, which involve nitrene insertion, are developing into an important alternative to classical methods of CN bond formation for building functionalized amines. Both metal–phenyliodinane and metal–nitrene intermediates have been suggested to be responsible for nitrene delivery, and concerted insertion via a singlet nitrenoid or radical recombination via a triplet nitrenoid may be feasible pathways in CN bond formation. For the answer, turn to their Full Paper on page 1101 ff.
Version of Record online: 27 AUG 2007 | DOI: 10.1002/asia.200790026
Version of Record online: 27 AUG 2007 | DOI: 10.1002/asia.200790027
Nicole Holub and Siegfried Blechert
Version of Record online: 16 JUL 2007 | DOI: 10.1002/asia.200700072
Anything's possible: Ring-rearrangement metathesis is highly efficient for constructing complex structures. An examination of the driving forces, limits, and scope of this reaction, as well as recent applications and future perspectives, is presented in this Focus Review. Ns=nitrobenzenesulfonyl.
Sadafumi Nishihara, Tomoyuki Akutagawa, Daisuke Sato, Sadamu Takeda, Shin-ichiro Noro and Takayoshi Nakamura
Version of Record online: 3 AUG 2007 | DOI: 10.1002/asia.200700010
Round and round we go: (Anilinium)-(crown-6) dynamic supramolecular cations undergo different modes of rotation in the solid state. The 180° flip-flop motion of anilinium and the rotation of crown-6 were confirmed from solid-state NMR spectra. Multimolecular rotations of different motional freedoms were also observed simultaneously.
Koushik Dhara, Santanu Karan, Jagnyeswar Ratha, Partha Roy, Goutam Chandra, Mario Manassero, Biswanath Mallik and Pradyot Banerjee
Version of Record online: 16 JUL 2007 | DOI: 10.1002/asia.200700152
A zinc sink: A selective fluorescent sensor for the detection of Zn2+ in cultured living cells (B16F10 mouse melanoma and A375 human melanoma) and rat hippocampal slices can be found in a 2D coordination compound that dissociates in solution to produce a metalloligand that binds with Zn2+. This system is highly selective and suitable for biological applications.
Version of Record online: 21 AUG 2007 | DOI: 10.1002/asia.200700068
Alone yet together: DFT calculations elucidate the catalytic process of a dirhodium tetracarboxylate catalyzed intramolecular CH bond-amidation reaction. Out of six reaction pathways that involve a metal–nitrene complex, the singlet concerted pathway that produces the product with retention of chirality at C is predicted to be the predominant one.
Ivan R. Corrêa Jr., Andrea Nören-Müller, Horst-Dieter Ambrosi, Sven Jakupovic, Krishna Saxena, Harald Schwalbe, Markus Kaiser and Herbert Waldmann
Version of Record online: 8 AUG 2007 | DOI: 10.1002/asia.200700125
Inspired by nature: The first class of inhibitors for a mycobacterial phosphatase required for survival of the bacterium in the host is developed by means of biology-oriented synthesis. The highly substituted indolo[2,3-a]quinolizidines are produced by a combination of a vinylogous Mannich–Michael reaction and phosgene- or acid-mediated ring closure.
Pauline C. Stanislawski, Anthony C. Willis and Martin G. Banwell
Version of Record online: 10 AUG 2007 | DOI: 10.1002/asia.200700155
A radical synthesis: The nonnatural enantiomer, (−)-1, of erythramine can be prepared thus: simultaneous forming of the A and C rings by AgI-induced electrocyclic ring opening of the key intermediate 2 followed by trapping of the resulting π-allyl cation by the tethered nitrogen atom (3). The derived iodide 4 undergoes radical addition/elimination to form the B ring. Alloc=allyloxycarbonyl.
Xuping Sun, Yan Du, Lixue Zhang, Shaojun Dong and Erkang Wang
Version of Record online: 6 JUL 2007 | DOI: 10.1002/asia.200700002
An electrifying attraction: [Ru(bpy)3]2+-containing microstructures can be formed through electrostatic assembly of [Ru(bpy)3]2+ and [Fe(CN)6]3− by direct mixing of aqueous [Ru(bpy)3]Cl2 and K3[Fe(CN)6]. Both the molar ratio and concentration of the reactants strongly influence the formation of these microstructures, which exhibit excellent electrochemiluminescent behavior.
Masaki Shimizu, Katsuhiro Shimono and Tamejiro Hiyama
Version of Record online: 2 AUG 2007 | DOI: 10.1002/asia.200700153
Melting pot: Triple-aldehyde addition of 1,2,3,4-tetraborylbut-2-ene upon heating at 100 °C gives 2,3-bis(alkylidene)alkane-1,5-diols as a single stereoisomer. The cascade reaction, which occurs in situ during preparation of the tetraborylbutene reagent, involves sequential conversion of four CB bonds into two CC bonds and one CC bond. B=pinacolatoboryl.
Yoshihiro Sohtome, Nobuko Takemura, Keisuke Takada, Rika Takagi, Toshitsugu Iguchi and Kazuo Nagasawa
Version of Record online: 16 JUL 2007 | DOI: 10.1002/asia.200700145
Helping each other: The guanidine–thiourea heterobifunctional compound 1 catalyzes diastereo- and enantioselective nitroaldol reactions at a chiral reaction interface. Addition of KI is crucial for inhibiting the retro-nitroaldol reaction and achieving high asymmetric induction. Bn=benzyl.
Taichi Kano, Youhei Tanaka and Keiji Maruoka
Version of Record online: 19 JUL 2007 | DOI: 10.1002/asia.200700122
It's cool to be different: The axially chiral diamine (R)-1 was designed and used successfully with p-TsOH⋅H2O as an organocatalyst in the Diels–Alder reaction of cyclopentadiene with α,β-unsaturated aldehydes. Although the Diels–Alder reaction of such compounds is inherently endo selective, (R)-1 exhibits unprecedented levels of exo selectivity. Ts=toluenesulfonyl.
Yasuhiro Morisaki, Yuko Ouchi, Kensuke Naka and Yoshiki Chujo
Version of Record online: 19 JUL 2007 | DOI: 10.1002/asia.200700095
Like Ps in a pod: Optically active oligophosphines with chiral phosphorus atoms and their corresponding optically inactive counterparts can be synthesized by a step-by-step oxidative-coupling reaction. Their properties depend on the enantiomeric purity as well as the oligomer chain length.
Takeji Takamura-Enya, Masanobu Kawanishi, Takashi Yagi and Yoshiharu Hisamatsu
Version of Record online: 21 AUG 2007 | DOI: 10.1002/asia.200700061
The Tropic of Cancer: 3-Nitrobenzanthrone (1) is a powerful carcinogen present in the atmosphere. With palladium-catalyzed aryl amination as a key step, several DNA adducts, the formation of which is recognized as a trigger of chemical carcinogenesis, can be synthesized. Some of these adducts are formed from the reaction of DNA with metabolic activation products of 1. dA=2′-deoxyadenosine, dG=2′-deoxyguanosine, R=H, Ac.
Version of Record online: 27 AUG 2007 | DOI: 10.1002/asia.200790028