16721-45-2Relevant articles and documents
Efficient access to novel furanofurone compounds from quinic acid: Studies of inter-and intramolecular Wittig reactions on lactones
Baptistella, Lúcia Helena Brito,Jorge, André De Carvalho
, p. 3045 - 3049 (2007)
(-)-Quinic acid has been converted into derivatives of a furo[3,2-b]furan-2-one system using Wittig olefination reactions of lactones. Studies for this transformation included the use of microwave-assisted reactions. Georg Thieme Verlag Stuttgart.
Strong deshielding in aromatic isoxazolines
Ungvarská Ma?u?ká, Lucia,Vilková, Mária,Ko?í?ek, Jozef,Imrich, Ján
, p. 17 - 27 (2016)
Very strong proton deshielding was found in di/tri-aromatic isoxazoline regioisomers prepared from acridin-4-yl dipolarophiles and stable benzonitrile oxides (BNO). Three alkenes, (acridin-4-yl)-CH=CH-R (R = COOCH3, Ph, and CONH2), r
Novel photocyclization of β,γ-unsaturated oximes
Armesto, Diego,Ramos, Ana,Ortiz, Maria J.,Mancheno, Maria J.,Mayoral, Elena P.
, p. 514 - 516 (1995)
Previously, β,γ-unsaturated oximes were thought to be photochemically unreactive.The present study reports the first three examples of photocyclization of β,γ-unsaturated ketoximes to yield 4,5-dihydroisoxazole derivatives.Typically, acetophenone-sensitiz
Ylide-Stabilized Phosphenium Cations: Impact of the Substitution Pattern on the Coordination Chemistry
Stalder, Tobias,Krischer, Felix,Steinert, Henning,Neigenfind, Philipp,Gessner, Viktoria H.
, (2022/01/11)
Although N-heterocyclic phosphenium (NHP) cations have received considerable research interest due to their application in organocatalysis, including asymmetric synthesis, phosphenium cations with other substitution patterns have hardly been explored. Her
Quaternary Phosphonium Carboxylates: Structure, Dynamics and Intriguing Olefination Mechanism
Vetter, Anna C.,Müller-Bunz, Helge,Muldoon, Jimmy,Nikitin, Kirill
, p. 1745 - 1752 (2022/01/12)
We have earlier shown how the Wittig chemistry can be done using novel Eigenbase phosphonium carboxylate reagents. Here we discuss the phenomenon of ion pairing, their solution tautomerism, solid-state structure, and mechanistic aspects of olefination. The results point to a complex process involving unfamiliar H-bond-driven ion-pair equilibria followed by standard Wittig reaction steps.
Silver-Catalysed Hydroarylation of Highly Substituted Styrenes
Dalton, Toryn,Gre?ies, Steffen,Das, Mowpriya,Niehues, Maximilian,Schrader, Malte L.,Gutheil, Christian,Ravoo, Bart Jan,Glorius, Frank
supporting information, p. 8537 - 8541 (2021/03/16)
Hydroarylation is an effective strategy to rapidly increase the complexity of organic structures by transforming flat alkene moieties into three-dimensional frameworks. Many strategies have already been developed to achieve the hydroarylation of styrenes,
Substituted dienes prepared from betulinic acid – Synthesis, cytotoxicity, mechanism of action, and pharmacological parameters
Frydrych, Ivo,Urban, Milan,?arek, Jan,Benická, Sandra,D?ubák, Petr,Gurská, Soňa,Hajdúch, Marián,Kotulová, Jana,Li?ková, Barbora,Olejníková, Denisa,Pokorny, Jan
, (2021/07/28)
A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22, 4.30, 4.33, 4.39 had IC50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC50 and almost complete inhibition at 5 × IC50. Interestingly, compound 4.39 at 5 × IC50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39, therefore 4.22 was the finally selected candidate for the development of anticancer drug.
Asymmetric synthesis and biological evaluation of (+)-cardiobutanolide, (?)-3-deoxycardiobutanolide and analogues as antiproliferative agents
Francuz, Jovana,Jakimov, Dimitar,Popsavin, Mirjana,Popsavin, Velimir,Benedekovi?, Goran,Kesi?, Jelena,Koji?, Vesna,Kova?evi?, Ivana,Rodi?, Marko V.,Zelenovi?, Bojana Sre?o
, (2021/08/30)
Two natural products, (+)-cardiobutanolide and (?)-3-deoxycardiobutanolide, as well as five new analogues, were synthesized in several steps that included zinc-mediated THF ring opening, subsequent stereoselective olefination, and final Sharpless asymmetric dihydroxylation. In vitro antitumour activities of these compounds were evaluated against a panel of eight human tumour cell lines and one normal cell line. Some of compounds displayed powerful effects against tumour cells, but none of them were active toward normal cells. A SAR study revealed that the change of configuration at the C-6 and C-7 position of (+)-cardiobutanolide decreases antitumour activity of analogues. It also appears that the presence of a hydroxyl group at the C-3 position increases the activity of this type of lactones. A comparison of activities of conformationally rigid lactone goniofufurone with that of more flexible cardiobutanolide and 3-deoxycardiobutanolide indicates that steric flexibility has a positive effect on cytotoxicity. It was also confirmed that removal of the phenyl group may result in analogues of higher activity. Flow cytometry analysis revealed that the synthesized compounds did not induce apoptosis and necrosis of K562 cells. However, Western blot analysis showed that all compounds but one had an increased Bax/Bcl-2 protein expression ratio.
Catalytic Systems for Production of 1-Hexene by Selective Ethylene Trimerization
Afanas’ev, V. V.,Bespalova, N. B.,Cheredilin, D. N.,Kozlova, G. A.,Senin, A. A.,Sheloumov, A. M.
, p. 55 - 68 (2020/02/25)
Abstract: New chromium complexes with diphosphine ligands have been obtained by the reaction of chromium(III) hexahydrate and diphosphines in acetone. The structure of chromium(III) complex 4 containing water molecule and 1,2-bis(diphenylphosphino)benzene as ligands and that of two chromium(III) complexes (12 and 13) with 1,2-bis(diphenylphosphino)benzene ligands containing alkenyl substituents in the ortho-position of one of the phenyl groups at the phosphorous atom have been determined using X-ray diffraction analysis. The catalytic properties of the obtained complexes in the composition of catalytic systems for ethylene trimerization have been studied. It has been shown that the obtained series of catalytic systems manifests high activity in the process of ethylene trimerization to 1-hexene, with the process selectivity exceeding 94%. The highest value of productivity amongst known selective catalytic systems for trimerization was achieved using a chromium complex 13 bearing the 2-methylprop-1-enyl group at the ortho-position of one of the phenyl groups. The influence of temperature, pressure, the nature of the solvent and the composition of the catalytic system on the parameters of the process of ethylene trimerization to form 1-hexene has been determined.
Chromene- And quinoline-3-carbaldehydes: Useful intermediates in the synthesis of heterocyclic scaffolds
Rocha, Djenisa H.A.,Batista, Vasco F.,Balsa, Emanuel J.F.,Pinto, Diana C.G.A.,Silva, Artur M.S.
, (2020/10/02)
Chromenes and quinolines are recognized as important scaffolds in medicinal chemistry. Herein, the efficient use of chromene- and quinoline-3-carbaldehydes to synthesize other valuable heterocycles is described. These carbaldehydes are obtained in excelle
