5728-46-1Relevant articles and documents
Understanding the remarkable difference in liquid crystal behaviour between secondary and tertiary amides: The synthesis and characterisation of new benzanilide-based liquid crystal dimers
Strachan, Grant J.,Harrison, William T. A.,Storey, John M. D.,Imrie, Corrie T.
, p. 12600 - 12611 (2021)
A number of liquid crystal dimers have been synthesised and characterised containing secondary or tertiary (N-methyl) benzanilide-based mesogenic groups. The secondary amides all form nematic phases, and we present the first example of an amide to show the twist-bend nematic (NTB) phase. Only two of the correspondingN-methylated dimers formed a nematic phase and with greatly reduced nematic-isotropic transition temperatures. Characterisation using 2D ROESY NMR experiments, DFT geometry optimisation and X-ray diffraction reveal that there is a change in the preferred conformation of the benzanilide core on methylation, fromZtoE. The rotational barrier around the N-C(O) bond has been measured using variable temperature1H NMR spectroscopy. This dramatic change in shape accounts for the remarkable difference in liquid crystalline behaviour between these secondary and tertiary amide-based materials.
Amplification of Elementary Surface Reaction Steps on Transition Metal Surfaces Using Liquid Crystals: Dissociative Adsorption and Dehydrogenation
Yu, Huaizhe,Szilvási, Tibor,Wang, Kunlun,Gold, Jake I.,Bao, Nanqi,Twieg, Robert J.,Mavrikakis, Manos,Abbott, Nicholas L.
, p. 16003 - 16013 (2019)
Elementary reaction steps, including adsorption and dissociation, of a range of molecular adsorbates on transition metal surfaces have been elucidated in the context of chemical catalysis. Here we leverage this knowledge to design liquid crystals (LCs) supported on ultrathin polycrystalline gold films (predominant crystallographic face is (111)) that are triggered to undergo orientational transitions by dissociative adsorption and dehydrogenation reactions involving chlorine and carboxylic acids, respectively, thus amplifying these atomic-scale surface processes in situ into macroscopic optical signals. We use electronic structure calculations to predict that 4′-n-pentyl-4-biphenylcarbonitrile (5CB), a room temperature nematic LC, does not bind to Au(111) in an orientation that changes upon dissociative adsorption of molecular chlorine, a result validated by experiments. In contrast, 4-cyano-4-biphenylcarboxylic acid (CBCA) is calculated to bind strongly to Au(111) in a perpendicular orientation via dehydrogenation of the carboxylic acid group, which we confirmed using polarization-modulation infrared reflection-absorption spectroscopy. A maximum coverage of 0.07 monolayer of CBCA on the gold surface is sufficient to cause a perpendicular orientation of the LC. Dissociative adsorption of Cl2 gas on the gold surface, resulting in 0.5 monolayer coverage of Cl, displaces CBCA from Au(111) and thus triggers a strikingly visible change in orientation of the LC. Infrared spectroscopy established the orientation of adsorbed CBCA to be parallel to the Cl covered surface, with the COOH plane perpendicular to the surface, as predicted by first-principles calculations. These results demonstrate the use of first-principles calculations and transition metal surfaces to design LCs that report in situ targeted atomic-scale surface processes.
Lead discovery, chemical optimization, and biological evaluation studies of novel histone methyltransferase SET7 small-molecule inhibitors
Cao, Liyuan,Ding, Hong,Han, Jie,Hou, Zeng,Li, Yuanqing,Luo, Cheng,Min, Wenjian,Niu, Ao,Yang, Peng,Zhang, Rukang
supporting information, (2020/03/23)
The post-translational modifications of histones, including histone methylation and demethylation, control the expression switch of multiple genes. SET domain-containing lysine methyltransferase 7 (SET7) is the only methyltransferase, which can specifically monomethylate lysine-4 of histone H3 (H3K4me1) and play critical roles in various diseases, including breast cancer, hepatitis C virus (HCV), atherosclerotic vascular disease, diabetes, prostate cancer, hepatocellular carcinoma, and obesity. However, several known SET7 inhibitors exhibit weak activity or poor selectivity. Therefore, the development of novel SET7 inhibitors is highly desirable and of great clinical value. In this study, we identified 2–79 as a new hit compound by structure-based virtual screening and further AlphaLISA-based biochemical evaluation. Via chemical optimization, the synthesized compound DC21 was confirmed as a potent SET7 inhibitor with an IC50 value of 15.93 μM. The interaction between DC21 and SET7 was also validated through SPR experiment. Especially, DC21 retarded proliferation of MCF7 cells with an IC50 value of 25.84 μM in cellular level. In addition, DC21 has good selectivity for several other epigenetic targets, such as SUV39H1, G9a, NSD1, DOT1L and MOF. DC21 can serve as a lead compound to develop more potential SET7 inhibitors and as a chemical probe for SET7 biological function studies.
Magnetite tethered mesoionic carbene-palladium (II): An efficient and reusable nanomagnetic catalyst for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions in aqueous medium
Kempasiddhaiah, Manjunatha,Kandathil, Vishal,Dateer, Ramesh B.,Sasidhar, Balappa S.,Patil, Shivaputra A.,Patil, Siddappa A.
, (2019/03/07)
In this paper, a highly active, air- and moisture-stable and easily recoverable magnetic nanoparticles tethered mesoionic carbene palladium (II) complex (MNPs-MIC-Pd) as nanomagnetic catalyst was successfully synthesized by a simplistic multistep synthesis under aerobic conditions using commercially available inexpensive chemicals for the first time. The synthesized MNPs-MIC-Pd nanomagnetic catalyst was in-depth characterized by numerous physicochemical techniques such as FT-IR, ICP-AES, FESEM, EDS, TEM, p-XRD, XPS, TGA and BET surface area analysis. The prepared MNPs-MIC-Pd nanomagnetic catalyst was used to catalyze the Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions and exhibited excellent catalytic activity for various substrates under mild reaction conditions. Moreover, MNPs-MIC-Pd nanomagnetic catalyst could be easily and rapidly recovered by applying an external magnet. The recovered MNPs-MIC-Pd nanomagnetic catalyst exhibited very good catalytic activity up to ten times in Suzuki–Miyaura and five times in Mizoroki–Heck cross-coupling reactions without considerable loss of its catalytic activity. However, MNPs-MIC-Pd nanomagnetic catalyst shows notable advantages such as heterogeneous nature, efficient catalytic activity, mild reaction conditions, easy magnetic work up and recyclability.
