13125-68-3Relevant articles and documents
Affinity modulation of photoresponsive hosts for fullerenes: Light-gated corannulene tweezers
Barbero, Héctor,Ferrero, Sergio,álvarez-Miguel, Lucía,Gómez-Iglesias, Patricia,Miguel, Daniel,álvarez, Celedonio M.
, p. 12964 - 12967 (2016)
Six azobenzene derivatives bearing polyaromatic fragments have been prepared and their reversible photoisomerization has been assessed. Corannulene-functionalized molecules have demonstrated excellent switchable hosting abilities towards fullerenes in which an interesting range of affinities has been found. The success of this design relies upon the reversible formation and destruction of tweezer-like structures.
Rh(III)-Catalyzed bilateral cyclization of aldehydes with nitrosos toward unsymmetrical acridines proceeding with C-H functionalization enabled by a transient directing group
Hu, Weiming,Zheng, Qingheng,Sun, Song,Cheng, Jiang
, p. 6263 - 6266 (2017)
A Rh(iii)-catalyzed bilateral cyclization was developed for the efficient construction of acridines proceeding with C-H functionalization whereby in situ formation and removal of an imino transient directing group in the presence of catalytic amount of BnNH2 are achieved. In this transformation, a sequential Rh(iii)-catalyzed C-H amination, cyclization, and aromatization process was involved.
Photoswitchable Magnetic Resonance Imaging Contrast by Improved Light-Driven Coordination-Induced Spin State Switch
Dommaschk, Marcel,Peters, Morten,Gutzeit, Florian,Schütt, Christian,N?ther, Christian,S?nnichsen, Frank D.,Tiwari, Sanjay,Riedel, Christian,Boretius, Susann,Herges, Rainer
, p. 7552 - 7555 (2015)
We present a fully reversible and highly efficient on-off photoswitching of magnetic resonance imaging (MRI) contrast with green (500 nm) and violet-blue (435 nm) light. The contrast change is based on intramolecular light-driven coordination-induced spin state switch (LD-CISSS), performed with azopyridine-substituted Ni-porphyrins. The relaxation time of the solvent protons in 3 mM solutions of the azoporphyrins in DMSO was switched between 3.5 and 1.7 s. The relaxivity of the contrast agent changes by a factor of 6.7. No fatigue or side reaction was observed, even after >100 000 switching cycles in air at room temperature. Electron-donating substituents at the pyridine improve the LD-CISSS in two ways: better photostationary states are achieved, and intramolecular binding is enhanced.
Continuous Flow Synthesis of Azoxybenzenes by Reductive Dimerization of Nitrosobenzenes with Gel-Bound Catalysts
Schmiegel, Carsten J.,Berg, Patrik,Obst, Franziska,Schoch, Roland,Appelhans, Dietmar,Kuckling, Dirk
, p. 1628 - 1636 (2021/03/15)
In the search for a new synthetic pathway for azoxybenzenes with different substitution patterns, an approach using a microfluidic reactor with gel-bound proline organocatalysts under continuous flow is presented. Herein the formation of differently substituted azoxybezenes by reductive dimerization of nitrosobenzenes within minutes at mild conditions in good to almost quantitative yields is described. The conversion within the microfluidic reactor is analyzed and used for optimizing and validating different parameters. The effects of the different functionalities on conversion, yield, and reaction times are analyzed in detail by NMR. The applicability of this reductive dimerization is demonstrated for a wide range of differently substituted nitrosobenzenes. The effects of these different functionalities on the structure of the obtained azoxyarenes are analyzed in detail by NMR and single-crystal X-ray diffraction. Based on these results, the turnover number and the turnover frequency were determined.
Active ester functionalized azobenzenes as versatile building blocks
Schultzke, Sven,Staubitz, Anne,Walther, Melanie
supporting information, (2021/07/12)
Azobenzenes are important molecular switches that can still be difficult to functionalize selectively. A high yielding Pd-catalyzed cross-coupling method under mild conditions for the introduction of NHS esters to azobenzenes and diazocines has been established. Yields were consistently high with very few exceptions. The NHS functionalized azobenzenes react with primary amines quantitatively. These amines are ubiquitous in biological systems and in material science.
