Max Martin

Abstract

Extended family: The reaction of a calcium hydride complex with an N-heterocyclic olefin (NHO) gave a new bifunctional NHC-based ligand which shows strongly increased ylide character in comparison to the parent NHO.

[Communication]
Andrea Causero, Holger Elsen, Jürgen Pahl, Sjoerd Harder
Angew. Chem. Int. Ed., May 05, 2017, https://doi.org/10.1002/anie.201703037 Read article

Abstract

Metallosupramolecular ChemistryThe synthesis and properties of a supramolecular octanuclear cage exhibiting spin-crossover behavior in solution are demonstrated by A. Lützen and co-workers in their Communication on page 4930 ff.

[Frontispiece]
Niklas Struch, Christoph Bannwarth, Tanya K. Ronson, Yvonne Lorenz, Bernd Mienert, Norbert Wagner, Marianne Engeser, Eckhard Bill, Rakesh Puttreddy, Kari Rissanen, Johannes Beck, Stefan Grimme, Jonathan R. Nitschke, Arne Lützen
Angew. Chem. Int. Ed., April 18, 2017, https://doi.org/10.1002/anie.201781861 Read article

The synthesis of a carbon nanobelt, comprising a closed loop of fully fused edge-sharing benzene rings, has been an elusive goal in organic chemistry for more than 60 years. Here we report the synthesis of one such compound through iterative Wittig reactions followed by a nickel-mediated aryl-aryl coupling reaction. The cylindrical shape of its belt structure was confirmed by x-ray crystallography, and its fundamental optoelectronic properties were elucidated by ultraviolet-visible absorption, fluorescence, and Raman spectroscopic studies, as well as theoretical calculations. This molecule could potentially serve as a seed for the preparation of structurally well-defined carbon nanotubes. Authors: Guillaume Povie, Yasutomo Segawa, Taishi Nishihara, Yuhei Miyauchi, Kenichiro Itami

Abstract

Nature Chemistry. doi:10.1038/nchem.2758

Authors: Felix J. Rizzuto & Jonathan R. Nitschke

An interconverting system of three distinct stereoisomers of a cuboctahedral CoII-based cage is able to regulate the binding affinities of large anionic guests. Through cooperative templation with fullerene guests, the cage converts into a desymmetrized cage that in turn exhibits positive cooperativity in binding of an icosahedral anion; this interaction is anti-cooperative in the fullerene-free parent.

Sequence-selective encapsulation and protection of long peptides by a self-assembled Fe^II₈L₆ cubic cage

Nature Communications, Published online: 30 March 2017; doi:10.1038/ncomms14882

One of the challenges of synthetic self-assembled capsules is achieving selective recognition of specific cargoes. Here, authors synthesize a self-assembled porphyrin cubic cage that is capable of sequestering imidazole and thiazole-containing small molecules and peptides, protecting them from proteolysis.

As captivating as a butterfly: Different strategies toward stable superbenzoquinone (SBQ) derivatives were explored, and stable 4-tert-phenyl-substituted SBQ-Ph was obtained by appropriate kinetic blocking. SBQ-Ph (see structure) has an open-shell singlet ground state with moderate diradical character and adopts a butterfly-like geometry in the single crystal.

[Communication]
Guangwu Li, Hoa Phan, Tun Seng Herng, Tullimilli Y. Gopalakrishna, Chunchen Liu, Wangdong Zeng, Jun Ding, Jishan Wu
Angew. Chem. Int. Ed., March 30, 2017, https://doi.org/10.1002/anie.201700441 Read article

Subcomponent self-assembly results in octanuclear metallosupramolecular cages, which were structurally characterized by experimental and theoretical means. The iron(II) cages undergo spin-crossover in solution. This behavior is guest-dependent, as encapsulation of fullerene C₇₀ stabilizes the high-spin state and shifts the spin-transition temperature by as much as 20 K.

[Communication]
Niklas Struch, Christoph Bannwarth, Tanya K. Ronson, Yvonne Lorenz, Bernd Mienert, Norbert Wagner, Marianne Engeser, Eckhard Bill, Rakesh Puttreddy, Kari Rissanen, Johannes Beck, Stefan Grimme, Jonathan R. Nitschke, Arne Lützen
Angew. Chem. Int. Ed., March 30, 2017, https://doi.org/10.1002/anie.201700832 Read article

Doubly positive: The twofold Scholl cyclization of a 5,11-dinaphthyltetracene furnished an unsymmetrically cyclized product with a twisted π-surface and an absorption band reaching up to 950 nm. A combined experimental and theoretical study showed that such unsymmetric Scholl cyclizations can be rationalized by a mechanism that involves dicationic intermediates.

[Communication]
Chaolumen, Michihisa Murata, Atsushi Wakamiya, Yasujiro Murata
Angew. Chem. Int. Ed., March 30, 2017, https://doi.org/10.1002/anie.201701054 Read article

White whale of porphyrin researchers: The elusive cis tautomer of a free-base porphyrin has been isolated and structurally characterized for the first time. X-ray diffraction data show the presence of an unusual cis geometry. DFT calculations confirm the greater stability of this structure relative to the more commonly observed trans geometry.

[Communication]
Kolle E. Thomas, Laura J. McCormick, Hugo Vazquez-Lima, Abhik Ghosh
Angew. Chem. Int. Ed., March 29, 2017, https://doi.org/10.1002/anie.201701965 Read article

A BN-doped coronene derivative in which the central benzene ring has been replaced by a borazine core is described. UV/Vis absorption, emission, and electrochemical investigations show that the introduction of the central BN core induces a dramatic widening of the HOMO–LUMO gap and an enhancement of the blue-shifted emissive properties with respect to its all-carbon congener.

[Communication]
Jacopo Dosso, Jonathan Tasseroul, Francesco Fasano, Davide Marinelli, Nicolas Biot, Andrea Fermi, Davide Bonifazi
Angew. Chem. Int. Ed., March 21, 2017, https://doi.org/10.1002/anie.201700907 Read article

Confined coordination spaces in redox-active ruthenium(II) cages enable the photoinduced regio- and enantioselective coupling of naphthol and derivatives thereof. The photoreactions proceed under both aerobic and anaerobic conditions but by distinct pathways that nevertheless involve the same radical intermediates.

[Communication]
Jing Guo, Yao-Wei Xu, Kang Li, Li-Min Xiao, Sha Chen, Kai Wu, Xu-Dong Chen, Yan-Zhong Fan, Jun-Min Liu, Cheng-Yong Su
Angew. Chem. Int. Ed., March 01, 2017, DOI: 10.1002/anie.201611875. Read article