932-98-9Relevant articles and documents
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.
Pt nanoparticles on Ti3C2T: X -based MXenes as efficient catalysts for the selective hydrogenation of nitroaromatic compounds to amines
Chen, Qian,Fan, Guangyin,Jiang, Weidong
supporting information, p. 14914 - 14920 (2020/11/11)
The development of Pt nanocatalysts for the selective hydrogenation of nitroaromatic compounds to the corresponding amines is of great significance to solve the drawbacks associated with a low reserve of Pt. Herein, we develop a protocol for the preparation of a Pt/titanium carbide-based MXene heterostructure for the selective reduction of nitroaromatic compounds. In the heterostructure, well-defined and nano-sized metallic Pt crystallites are uniformly decorated on Ti3C2Tx nanosheets using a mild reducing agent of ammonia borane without additional stabilizing agents. The selective hydrogenation of p-chloronitrobenzene (p-CNB) to p-chloroaniline (p-CAN) was employed as a model reaction to investigate the catalytic performance of the as-synthesized heterostructure, denoted as Pt/Ti3C2Tx-D-AB. Notably, this catalyst can catalyze the complete conversion of p-CNB to p-CAN with 99.5% selectivity, superior to that of Pt/Ti3C2Tx-D-SB synthesized with sodium borohydride. The high performance of the present catalytic system can be ascribed to the well-dispersed Pt nanoparticles, the abundant surface electron-efficient Pt(0), and the synergistic catalysis between Pt/Ti3C2Tx-D-AB and water. This catalyst also shows generality toward the selective hydrogenation of a series of nitroaromatic compounds to the corresponding amines with high efficiency. The present study provides a strategy to synthesize efficient catalysts for catalytic applications.
A Photoswitchable Agonist for the Histamine H3 Receptor, a Prototypic Family A G-Protein-Coupled Receptor
Hauwert, Niels J.,Mocking, Tamara A. M.,Da Costa Pereira, Daniel,Lion, Ken,Huppelschoten, Yara,Vischer, Henry F.,De Esch, Iwan J. P.,Wijtmans, Maikel,Leurs, Rob
supporting information, p. 4531 - 4535 (2019/03/07)
Spatiotemporal control over biochemical signaling processes involving G protein-coupled receptors (GPCRs) is highly desired for dissecting their complex intracellular signaling. We developed sixteen photoswitchable ligands for the human histamine H3 receptor (hH3R). Upon illumination, key compound 65 decreases its affinity for the hH3R by 8.5-fold and its potency in hH3R-mediated Gi protein activation by over 20-fold, with the trans and cis isomer both acting as full agonist. In real-time two-electrode voltage clamp experiments in Xenopus oocytes, 65 shows rapid light-induced modulation of hH3R activity. Ligand 65 shows good binding selectivity amongst the histamine receptor subfamily and has good photolytic stability. In all, 65 (VUF15000) is the first photoswitchable GPCR agonist confirmed to be modulated through its affinity and potency upon photoswitching while maintaining its intrinsic activity, rendering it a new chemical biology tool for spatiotemporal control of GPCR activation.