21956-56-9Relevant articles and documents
Pd-Catalyzed Coupling of N-Tosylhydrazones with Benzylic Phosphates: Toward the Synthesis of Di- or Tri-Substituted Alkenes
Zhang, Kena,Provot, Olivier,Alami, Mouad,Tran, Christine,Hamze, Abdallah
, p. 1249 - 1261 (2022/02/07)
This study shows that various di- and tri-substituted alkenes with high chemoselectivity were obtained in good to high yields by coupling N-tosylhydrazones (NTHs) with benzylic phosphates as electrophilic partners. The obtained new catalytic system consis
Pd-Catalyzed Cross-Coupling of Organostibines with Styrenes to Give Unsymmetric (E)-Stilbenes and (1 E,3 E)-1,4-Diarylbuta-1,3-dienes and Fluorescence Properties of the Products
Zhang, Zhao,Zhang, Dejiang,Zhu, Longzhi,Zeng, Dishu,Kambe, Nobuaki,Qiu, Renhua
, p. 5317 - 5322 (2021/06/28)
A general and effective palladium-catalyzed cross-coupling of organostibines with styrenes to give (E)-olefins was disclosed. By the use of an organostibine reagent, this method can produce unsymmetric (E)-1,2-diarylethylenes and (1E,3E)-1,4-diarylbuta-1,3-dienes in good yields with high E/Z selectivity and good functional group tolerance. Resveratrol and DMU-212 were synthesized in high yield. The protocol can be extended to the synthesis of (1E,3E,5E)-1,6-diphenylhexa-1,3,5-triene in 40% yield. Products 5e, 5f, and 7a showed good photoluminescence quantum yields ranging from 72 to 99%.
Stereospecific Iron-Catalyzed Carbon (sp2)-Carbon (sp2) Cross-Coupling of Aryllithium with Vinyl Halides
Chen, Peng,Peng, Xiao-Shui,Wang, Zhi-Yong,Wong, Henry N. C.
supporting information, p. 4385 - 4390 (2021/06/27)
We present herein an efficient synthetic protocol involving iron-catalyzed cross-coupling of organolithium compounds with vinyl halides as key coupling partners. More than 30 examples were obtained with moderate to good yields and high stereoselectivities. The practicality of this method is evidenced by a gram-scale synthesis. In addition, a preliminary mechanistic investigation was also performed.
METHODS OF ARENE ALKENYLATION
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Page/Page column 18; 24; 52; 55-56; 64-65, (2021/11/26)
The present disclosure provides for a rhodium-catalyzed oxidative arene alkenylation from arenes and styrenes to prepare stilbene and stilbene derivatives. For example, the present disclosure provides for method of making arenes or substituted arenes, in particular stilbene and stilbene derivatives, from a reaction of an optionally substituted arene and/or optionally substituted styrene. The reaction includes a Rh catalyst or Rh pre-catalyst material and an oxidant, where the Rh catalyst or Rh catalyst formed Rh pre-catalyst material selectively functionalizes CH bond on the arene compound (e.g., benzene or substituted benzene).
Two resveratrol analogs, pinosylvin and 4,4′-dihydroxystilbene, improve oligoasthenospermia in a mouse model by attenuating oxidative stress via the Nrf2-ARE pathway
Cheng, C. Yan,Gong, Sheng-nan,Sang, Meng-meng,Sun, Fei,Wang, Cheng-niu,Yang, Jin-fei
, (2020/10/02)
Two synthesized resveratrol analogs from our laboratory, namely pinosylvin (3,5-dihydroxy-trans-stilbene, PIN) and 4,4′-dihydroxystilbene (DHS), have been carefully evaluated for treatment of oligoasthenospermia. Recent studies have demonstrated that PIN and DHS improved sperm quality in the mouse. However, the mechanism of action of PIN and DHS on oligoasthenospermia remains unknown. Herein, we investigated the mechanistic basis for improvements in sperm parameters by PIN and DHS in a mouse model of oligoasthenospermia induced by treatment with busulfan (BUS) at 6 mg/kg b.w. Two weeks following busulfan treatment, mice were administered different concentrations of PIN or DHS daily for 2 consecutive weeks. Thereafter, epididymal sperm concentration and motility were determined, and histopathology of the testes was performed. Serum hormone levels including testosterone (T), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were measured using corresponding specific enzyme-linked immunosorbent assay (ELISA) kits. Testicular mRNA expression profiles were determined by RNA sequencing analysis. These findings were validated by quantitative real-time PCR, western blotting and ELISA. Both PIN and DHS improved the epididymal sperm concentration and motility, enhanced testosterone levels, and promoted testicular morphological recovery following BUS treatment. PIN treatment was found to significantly reduce oxidative stress via the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE)-dependent antioxidant, glutathione peroxidase 3. DHS treatment significantly reduced oxidative stress via the Nrf2-ARE-dependent antioxidants glutathione S-transferase theta 2 and glutathione S-transferase omega 2. In summary, PIN and DHS ameliorated oligoasthenospermia in this mouse model by attenuating oxidative stress via the Nrf2-ARE pathway.
Novel resveratrol derivatives have diverse effects on the survival, proliferation and senescence of primary human fibroblasts
Birar, Vishal C.,Faragher, Richard G. A.,Ostler, Elizabeth L.,Sheerin, Angela N.
, p. 817 - 826 (2020/08/17)
Resveratrol alters the cytokinetics of mammalian cell populations in a dose dependent manner. Concentrations above 25–50 μM typically trigger growth arrest, senescence and/or apoptosis in multiple different cell types. In contrast, concentrations below 10 μM enhance the growth of log phase cell cultures and can rescue senescence in multiple strains of human fibroblasts. To better understand the structural features that regulate these effects, a panel of 24 structurally-related resveralogues were synthesised and evaluated for their capacity to activate SIRT1, as determined by an ex-vivo SIRT1 assay, their toxicity, as measured by lactate dehydrogenase release, and their effects on replicative senescence in MRC5 human fibroblasts as measured by their effects on Ki67 immunoreactivity and senescence-associated β galactosidase activity. Minor modifications to the parent stilbene, resveratrol, significantly alter the biological activities of the molecules. Replacement of the 3,5-dihydroxy substituents with 3,5-dimethoxy groups significantly enhances SIRT1 activity, and reduces toxicity. Minimising other strong conjugative effects also reduces toxicity, but negatively impacts SIRT1 activation. At 100 μM many of the compounds, including resveratrol, induce senescence in primary MRC5 cells in culture. Modifications that reduce or remove this effect match those that reduce toxicity leading to a correlation between reduction in labelling index and increase in LDH release. At 10 μM, the majority of our compounds significantly enhance the growth fraction of log phase cultures of MRC5 cells, consistent with the rescue of a subpopulation of cells within the culture from senescence. SIRT1 activation is not required for rescue to occur but enhances the size of the effect.
Synthesis of Stilbenes by Rhodium-Catalyzed Aerobic Alkenylation of Arenes via C-H Activation
Jia, Xiaofan,Frye, Lucas I.,Zhu, Weihao,Gu, Shunyan,Gunnoe, T. Brent
supporting information, p. 10534 - 10543 (2020/06/08)
Arene alkenylation is commonly achieved by late transition metal-mediated C(sp2)-C(sp2) cross-coupling, but this strategy typically requires prefunctionalized substrates (e.g., with halides or pseudohalides) and/or the presence of a directing group on the arene. Transition metal-mediated arene C-H activation and alkenylation offers an alternative method to functionalize arene substrates. Herein, we report a rhodium-catalyzed oxidative arene alkenylation from arenes and styrenes to prepare stilbene and stilbene derivatives. The reaction is successful with several functional groups on both the arene and the olefin including fluoride, chloride, trifluoromethyl, ester, nitro, acetate, cyanide, and ether groups. Reactions of monosubstituted arenes are selective for alkenylation at the meta and para positions, generally with approximately 2:1 selectivity, respectively. Resveratrol and (E)-1,2,3-trimethoxy-5-(4-methoxystyryl)benzene (DMU-212) are synthesized by this single-step approach in high yield. Comparison with palladium catalysis showed that rhodium catalysis is more selective for meta-functionalization for monosubstituted arenes and that the Rh catalysis has better tolerance of halogen groups.
Pinosylvine, application of the pinosylvine and preparation method of same
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Paragraph 0020, (2020/10/21)
The invention provides pinosylvine which is a crystal compound, and the temperature of the pinosylvine is 153-155 DEG C; EI-MS m/Z: 212(M+). The pinosylvine is used for preparing medicines for treating oligoasthenozoospermia, and can also be used for prep
Electro-Olefination—A Catalyst Free Stereoconvergent Strategy for the Functionalization of Alkenes
Baumann, Andreas N.,Dechent, Jonas,Didier, Dorian,Jagau, Thomas C.,Müller, Nicolas,Music, Arif
supporting information, (2020/07/04)
Conventional methods carrying out C(sp2)?C(sp2) bond formations are typically mediated by transition-metal-based catalysts. Herein, we conceptualize a complementary avenue to access such bonds by exploiting the potential of electrochemistry in combination with organoboron chemistry. We demonstrate a transition metal catalyst-free electrocoupling between (hetero)aryls and alkenes through readily available alkenyl-tri(hetero)aryl borate salts (ATBs) in a stereoconvergent fashion. This unprecedented transformation was investigated theoretically and experimentally and led to a library of functionalized alkenes. The concept was then carried further and applied to the synthesis of the natural product pinosylvin and the derivatization of the steroidal dehydroepiandrosterone (DHEA) scaffold.
Tetranuclear Palladium Complexes of Abnormal N-Heterocyclic Carbene Ligands and their Catalytic Activities in Mizoroki-Heck Coupling Reaction of Electron-Rich Aryl Chlorides
Lee, Jhen-Yi,Su, Yong-Siang,Wang, Yu-Shan,Lee, Hon Man
, p. 4714 - 4726 (2019/09/03)
Based on the ligand scaffold of an imidazolyl/benziimidazolyl moiety and a N-CH2C(=O)NHPh substituent, two series of ligand precursors with ortho hydroxy groups incorporated on the N-phenyl rings were prepared. The structural fine tuning of the ligand scaffold allowed the synthesis of tetranuclear palladium complexes with abnormal N-heterocyclic carbene (aNHC) ligands. For precursors with C2-methyl blocking groups, pyridine-assisted C?H bond activation led to the formation of mononuclear tridentate palladium aNHC complexes or tetranuclear complexes with tridentate CNO donors. Representative mononuclear and tetranuclearpalladium aNHC complexes were structurally characterized by X-ray diffraction studies, revealing very short Pd?C bond distances. The tetranuclear palladium aNHC complexes were very effective in catalyzing Mizoroki-Heck coupling reaction, and were capable of employing a range of aryl chlorides including deactivated substrates with low palladium loading of 0.2 mol%. (Figure presented.).
