74518-95-9Relevant articles and documents
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
supporting information, 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%.
Direct trans-Selective Ruthenium-Catalyzed Reduction of Alkynes in Two-Chamber Reactors and Continuous Flow
Neumann, Karoline T.,Klimczyk, Sebastian,Burhardt, Mia N.,Bang-Andersen, Benny,Skrydstrup, Troels,Lindhardt, Anders T.
, p. 4710 - 4714 (2016/07/12)
An efficient trans-selective hydrogenation of alkynes under low hydrogen pressure and low reaction temperatures is reported, applying a commercially available ruthenium hydride complex. The developed reaction conditions, which tolerate a variety of functional groups, are carried out in a two-chamber setup with ex situ generated hydrogen. The reaction setup is highly suitable for deuterium labeling. The trans-selective hydrogenation was extrapolated to a transfer hydrogenation protocol, employing a packed bed immobilized ruthenium hydride catalyst in continuous flow with a retention time of only 10 min.
Size controlled synthesis of Pd nanoparticles in water and their catalytic application in C-C coupling reactions
Sawoo, Sudeshna,Srimani, Dipankar,Dutta, Piyali,Lahiri, Rima,Sarkar, Amitabha
experimental part, p. 4367 - 4374 (2009/09/30)
Catalytically active Pd nanoparticles have been synthesized in water by a novel reduction of Pd(II) with a Fischer carbene complex where polyethylene glycol (PEG) was used as stabilizer. PEG molecules wrap around the nanoparticles to impart stability and prevent agglomeration, yet leave enough surface area available on the nanoparticle for catalytic activity. Our method is superior to others in terms of rapid generation and stabilization of Pd nanoparticles in water with a cheap, readily available PEG stabilizer. The size of the nanoparticles generated can be controlled by the concentration of PEG in water medium. The size decreased with the increase in the PEG: Pd ratio. This aqueous nano-sized Pd is a highly efficient catalyst for Suzuki, Heck, Sonogashira, and Stille reaction. Water is used as the only solvent for the coupling reactions.
The effects of 4′-alkyl substituents on the mutagenic activity of 4-amino- and 4-nitrostilbenes in Salmonella typhimurium
Ludolph, Bj?rn,Klein, Markus,Erdinger, Lothar,Boche, Gernot
, p. 195 - 209 (2007/10/03)
Six derivatives of trans-4-aminostilbene bearing different alkyl groups in the 4′-position and six of the corresponding nitro compounds were synthesized and tested for their mutagenic potency in Salmonella typhimurium strains TA98 and TA100. Regarding the test series in presence of S9-mix, maximum activity was observed for those trans-4-aminostilbenes and trans-4-nitrostilbenes bearing small alkyl substituents like methyl and ethyl. More bulky substituents reduced the mutagenic potential in the order iso-propyl ethyl > iso-propyl > sec-butyl > tert-butyl). These trends have been compared with quantitative structure activity relationship (QSAR) model predictions, leading to the conclusion that steric demand is an important factor for mutagenicity of substituted aminostilbenes and nitrostilbenes. The unexpected result for the tert-butyl nitrostilbene tested with metabolic activation may be attributed to a different metabolic pathway.
Metabolic N-Hydroxylation. Use of Substituent Variation to Modulate the in Vitro Bioactivation of 4-Acetamidostilbenes
Hanna, Patrick E.,Gammans, Richard E.,Sehon, Russell D.,Lee, Man-Kil
, p. 1038 - 1044 (2007/10/02)
N-Hydroxylation is an obligate step in the bioactivation of carcinogenic aryl amides.Previous reports from this laboratory demonstrated that variation of the 4' substituent of trans-4-acetamidostilbene (1) has a marked effect on the rate of its in vitro m
