18513-98-9Relevant academic research and scientific papers
Synthesis and structure of bis-crown-containing stilbenes
Vedernikov,Basok,Gromov,Kuz'mina,Avakyan,Lobova,Kulygina,Titkov,Strelenko,Ivanov,Howard,Alfimov
, p. 843 - 854 (2005)
An improved procedure was proposed for the synthesis of stilbenes fused to two crown ether fragments at both benzene rings. The structure of new homologous symmetric bis-crown-containing stilbenes was determined by X-ray analysis. Relations were revealed
Selenenate Anions (PhSeO?) as Organocatalyst: Synthesis of trans-Stilbenes and a PPV Derivative
Zheng, Zhipeng,Trofymchuk, Oleksandra S.,Kurogi, Takashi,Varela, Elena,Mindiola, Daniel J.,Walsh, Patrick J.
supporting information, p. 659 - 666 (2020/01/02)
The selenenate anion (RSeO?) is introduced as an active organocatalyst for the dehydrohalogen coupling of benzyl halides to form trans-stilbenes. It is shown that RSeO? is a more reactive catalyst than the previously reported sulfur analogues (sulfenate anion, RSO?) and selenolate anions (RSe?) in the aforementioned reaction. This catalytic system was also applied to the benzylic-chloromethyl-coupling polymerization (BCCP) of a bis-chloromethyl arene to form ppv (poly(p-phenylene vinylene))-type polymers with high yields, Mn (average molecular weight) up to 13,000 and ? (dispersity) of 1.15. (Figure presented.).
In vitro study and structure-activity relationship analysis of stilbenoid derivatives as powerful vasorelaxants: Discovery of new lead compound
Chan, Sock Ying,Loh, Yean Chun,Oo, Chuan Wei,Yam, Mun Fei
, (2020/10/12)
The development of vasorelaxant as the antihypertensive drug is important as it produces a rapid and direct relaxation effect on the blood vessel muscles. Resveratrol (RV), as the most widely studied stilbenoid and the lead compound, inducing the excellent vasorelaxation effect through the multiple signalling pathways. In this study, the in vitro vascular response of the synthesized trans-stilbenoid derivatives, SB 1-8e were primarily evaluated by employing the phenylephrine (PE)-precontracted endothelium-intact isolated aortic rings. Herein we report trans-3,4,4′-trihydroxystilbene (SB 8b) exhibited surprisingly more than 2-fold improvement to the maximal relaxation (Rmax) of RV. This article also highlights the characterization of the aromatic protons in terms of their unique splitting patterns in 1H NMR.
Direct Conversion of Alcohols into Alkenes by Dehydrogenative Coupling with Hydrazine/Hydrazone Catalyzed by Manganese
Das, Uttam Kumar,Chakraborty, Subrata,Diskin-Posner, Yael,Milstein, David
supporting information, p. 13444 - 13448 (2018/09/14)
We have developed unprecedented methods for the direct transformation of primary alcohols to alkenes in the presence of hydrazine, and for the synthesis of mixed alkenes by the reaction of alcohols with hydrazones. The reactions are catalyzed by a manganese pincer complex and proceed in absence of added base or hydrogen acceptors, liberating dihydrogen, dinitrogen, and water as the only byproducts. The proposed mechanism, based on preparation of proposed intermediates and control experiments, suggests that the transformation occurs through metal–ligand cooperative N?H activation of a hydrazone intermediate.
Aerobic Oxidative Intramolecular Aromatic Coupling via Heterogeneous Metal Catalysts
Fujimoto, Shigenobu,Matsumoto, Kenji,Shindo, Mitsuru
supporting information, p. 3057 - 3061 (2016/10/09)
An aerobic, heterogeneously catalyzed oxidative intramolecular coupling reaction of aromatic compounds is reported here. Using commercially available, recyclable heterogeneous metal catalysts, the coupling reactions of o-terphenyls and 1,ω-biarylalkanes proceeded quickly under mild conditions, i.e., at room temperature under oxygen as a co-oxidant almost all within 1 h, to provide the corresponding coupled products like triphenylenes and phenanthrenes in good to excellent yields. This reaction is an easily handled, practical, and atom-economical coupling method, which is of great importance in modern organic syntheses. (Figure presented.).
A facile and rapid access to resveratrol derivatives and their radioprotective activity
Uzura, Saori,Sekine-Suzuki, Emiko,Nakanishi, Ikuo,Sonoda, Motohiro,Tanimori, Shinji
supporting information, p. 3886 - 3891 (2016/08/01)
A facile and rapid access to resveratrol derivatives has been achieved based on palladium-catalyzed oxidative Heck reaction of aryl boronic acids with styrenes followed by demethylation in moderate to good yields. A series of resveratrol derivatives with various functional groups has been synthesized easily. The radioprotective activity of synthesized compounds has also been evaluated using rat thymocytes. The results revealed that some resveratrol derivatives efficiently protected the thymocytes from radiation-induced apoptosis.
Flash-metathesis for the coupling of sustainable (poly)hydroxyl β-methylstyrenes from essential oils
Hitce,Crutizat,Bourdon,Vivès,Marat,Dalko-Csiba
supporting information, p. 3756 - 3761 (2015/07/15)
A cross-metathesis procedure was developed to synthetize symmetrical and non symmetrical stilbenes from sustainable resources. The reaction proceeds under solvent-free conditions and at low catalyst loading (down to 0.01 mol%) within a couple of minutes only (TOF up to 6.9 s-1), on multi-gram scale. The highly reactive β-methylstyrene substrates were homo-coupled not only as pure synthons but also as components of essential oils that were reacted directly in order to eliminate prior substrate isolation from the overall process.
Synthesis of 2-bromo-1-aryl-1H-indenes via a Ag(I) promoted domino 2π-electrocyclic ring-opening/4π-electrocyclization reaction of 1,2-diaryl substituted gem-dibromocyclopropanes
Rosocha, Gregory,Batey, Robert A.
, p. 8758 - 8768 (2013/09/23)
2-Bromo-1-aryl substituted indenes can be synthesized from 1,2-diaryl substituted gem-dibromocyclopropanes via a domino reaction sequence. The cascade reaction involves silver(I) promoted ionization and 2π-disrotatory electrocyclic ring-opening, followed by a 4π-conrotatory electrocyclic ring closing reaction of the allylic carbocation intermediate. Reaction conditions utilize silver tetrafluoroborate (AgBF4) in dichloroethane at 65 C. Selectivity effects for the electrocyclization were also studied. The 2-bromoindenes can be further functionalized using cross-coupling reactions, such as the Suzuki-Miyaura protocol. The alkene π-bond of the indenes can also be isomerized to give the thermodynamically more stable 2-bromo-3-aryl-1H-indene isomers using triethylamine in dichloromethane at room temperature.
Phosphorus(V)-catalyzed deoxydichlorination reactions of aldehydes
An, Jie,Tang, Xiaoping,Moore, Joshua,Lewis, William,Denton, Ross M.
, p. 8769 - 8776 (2013/09/23)
A phosphine oxide-catalyzed conversion of aldehydes into 1,1-dichlorides is reported. The reaction proceeds via a phosphorus(V)-catalysis manifold in which phosphine oxide turnover is achieved using oxalyl chloride as a consumable reagent. The new method is applicable to a range of aldehydes and, in combination with palladium-catalyzed reductive dimerization, gives rise to a new catalytic approach to the synthesis of stilbenes and a short formal synthesis of resveratrol.
Testing the 1,1,3,3-tetramethyldisiloxane linker in olefin metathesis
Jab?onka-Gronowska, Ewa,Witkowski, Bart?omiej,Horeglad, Pawe?,Gierczak, Tomasz,Grela, Karol
, p. 566 - 572 (2013/07/26)
Compounds 12-15, possessing two styrenes connected by a silicon linker [1,1,3,3 tetramethyl-di-siloxane], were synthesized, characterized and used as model compounds for the ring-closing metathesis (RCM) catalyzed by commercially available ruthenium catalysts 1, 2 and 3. The RCM reactions of 12 and 15 in the presence of catalysts 1 or 2 resulted exclusively in the formation of (E)-stilbenes. The RCM reactions of 13 and 14, compounds possessing alkoxide substituents in the ortho position to styrene functionality, were not observed in the presence of 2, presumably due to the formation of inactive Hoveyda type ruthenium complexes. The RCM of mixture of 12 and 15, with 2, was used for the detailed examination of the mechanism of metathesis reactions investigated in this work. They revealed that both inter- and intramolecular metathesis is possible, in this case, despite the use of siloxane linker.
