- Catalytic Asymmetric [3 + 2] Cycloaddition Reaction between Aurones and Isocyanoacetates: Access to Spiropyrrolines via Silver Catalysis
-
The first enantioselective formal [3 + 2] cycloaddition of aurone analogues with isocyanoacetates was developed via chiral Ag-complex catalysis. A variety of optically enriched spiro-1-pyrrolines were obtained in excellent yields, diastero- and enantioselectivities (up to 99% yield, >20:1 dr, >99% ee). This synthetic approach represents an extremely simple, efficient, and atom-economical method for spiro-1-pyrrolines synthesis.
- Wang, Zhi-Peng,Xiang, Sichuan,Shao, Pan-Lin,He, Yun
-
-
Read Online
- In quest of small-molecules as potent non-competitive inhibitors against influenza
-
A series of scaffolds namely aurones, 3-indolinones, 4-quinolones and cinnamic acid-piperazine hybrids, was designed, synthesized and investigated in vitro against influenza A/H1N1pdm09 virus. Designed molecules adopted different binding mode i.e., in 430-cavity of neuraminidase, unlike sialic acid and oseltamivir in molecular docking studies. All molecules reduced the viral titer and exhibited non-cytotoxicity along with cryo-protective property towards MDCK cells. Molecules (Z)-2-(3′-Chloro-benzylidene)-1,2-dihydro-indol-3-one (2f), (Z)-2-(4′-Chloro-benzylidene)-1,2-dihydro-indol-3-one (2g) and 2-(2′-Methoxy-phenyl)-1H-quinolin-4-one (3a) were the most interesting molecules identified in this research, endowed with robust potencies showing low-nanomolar EC50 values of 4.0 nM, 6.7 nM and 4.9 nM, respectively, compared to reference competitive and non-competitive inhibitors: oseltamivir (EC50 = 12.7 nM) and quercetin (EC50 = 0.56 μM), respectively. Besides, 2f, 2g and 3a exhibited good neuraminidase inhibitory activity in sub-micromolar range (IC50 = 0.52 μM, 3.5 μM, 1.3 μM respectively). Moreover, these molecules were determined as non-competitive inhibitors similar to reference non-competitive inhibitor quercetin unlike reference competitive inhibitor oseltamivir in kinetics studies.
- Malbari, Khushboo,Saha, Priyanka,Chawla-Sarkar, Mamta,Dutta, Shanta,Rai, Swita,Joshi, Mamata,Kanyalkar, Meena
-
-
- An unusual triazole synthesis from aurones
-
Attempts to prepare azido-substituted aurones via a copper-catalyzed azidation failed to afford the desired product, but instead resulted in an unusual triazole formation reaction. Further efforts noted that copper was not required for this reaction, but simply thermal treatment with sodium azide in a polar aprotic solvent. A wide range of substitution patterns were tolerated in this reaction to afford the interesting salicyl-substituted triazoles in modest to excellent yield. While the mechanism is not yet clear, a simple elimination/cyclization pathway seems unlikely given the failure of the reaction on the corresponding thioaurones, which feature an even better thiol leaving group. Regardless, the potential utility of these easily accessible, multifunctional compounds should engender further interest and applications.
- Kafle, Arjun,Bhattarai, Shrijiana,Handy, Scott T.
-
supporting information
p. 2337 - 2346
(2020/08/19)
-
- Unusual Olefinic C-H Functionalization of Simple Chalcones toward Aurones Enabled by the Rational Design of a Function-Integrated Heterogeneous Catalyst
-
Flavonoids, which are ubiquitous plant secondary metabolites obtained from chalcones, mostly possess 6-membered C-rings derived from 6-endo-trig cyclization of chalcones. However, aurones, which are a class of flavonoids that rarely occur naturally, possess unusual 5-membered C-rings biosynthesized from chalcones by mainly performing B-ring oxidation. Therefore, the chemical catalytic transformation from simple chalcones into aurones is attractive, because it overcomes the drawback of known limited enzyme catalysis. The catalytic transformation, however, has not yet been reported because of the preferential 6-membered ring formation as with the biosynthesis and the need for rare intramolecular olefinic C-H functionalization. Here, we developed the catalytic olefinic C-H functionalization of simple chalcones toward various aurones enabled by the rational design of a function-integrated heterogeneous catalyst - a Pd-on-Au bimetallic nanoparticle catalyst supported on CeO2 - using O2 in air as the sole oxidant without any additives. In this system, the four conditions that were required for the challenging transformation toward aurones were achieved by the respective components of the catalyst: (a) a supported Pd catalyst: a catalyst for the olefinic C-H functionalization of chalcones toward aurones, (b) an Au promoter: an improvement in the catalytic activity by stabilizing Pd(0), (c) a CeO2 support: the inhibition of the 6-endo-trig cyclization utilizing the adsorption of chalcones, and (d) a Pd-on-Au structure: the inhibition of Au-catalyzed flavone synthesis. This catalytic transformation will promote not only the pharmaceutical study of aurones but also the rational design of a heterogeneous catalyst for the development of organic reactions that are not yet realized by homogeneous catalysts or biocatalyst.
- Yatabe, Takafumi,Jin, Xiongjie,Mizuno, Noritaka,Yamaguchi, Kazuya
-
p. 4969 - 4978
(2018/06/08)
-
- Transition-metal-free synthesis of polysubstituted pyrrole derivatives via cyclization of methyl isocyanoacetate with aurone analogues
-
Presented herein is an unprecedented transition-metal-free cyclization of methyl isocyanoacetate with aurone analogues catalyzed by NaOH. Various 2,3,4-trisubstituted pyrroles were obtained in excellent yields (up to 99%). The high efficiency of this synthetic procedure, coupled with the operational simplicity and atom economy, makes it an attractive method for the synthesis of polysubstituted pyrroles.
- Wang, Zhi-Peng,He, Yun,Shao, Pan-Lin
-
supporting information
p. 5422 - 5426
(2018/08/12)
-
- A novel cyclization/oxidation strategy for a two-step synthesis of (Z)-aurone
-
An efficient and facile two-step strategy for the synthesis of (Z)-aurone from arylacetylenes and salicyladehydes, via silver(I) nitrate mediated cyclization/oxidation in the presence of potassium carbonate has been developed. The key feature of our metho
- Li, Siyuan,Jin, Feng,Viji, Mayavan,Jo, Hyeju,Sim, Jaeuk,Kim, Hak Sung,Lee, Heesoon,Jung, Jae-Kyung
-
supporting information
p. 1417 - 1420
(2017/03/17)
-
- An efficient synthesis of aurone derivatives by the tributylphosphine-catalyzed regioselective cyclization of o-alkynoylphenols
-
An organocatalytic regioselective synthes is of aurones from o-alkynoylphenols was achieved. A catalytic amount of tributylphosphine select ively induced the 5-exo cyclization of o-alkynoylphenols under ambient conditions leading to aurone derivatives in high to excellent yields.
- Saito, Koya,Yoshida, Masahito,Doi, Takayuki
-
supporting information
p. 141 - 143
(2015/02/19)
-
- Aurones as histone deacetylase inhibitors: Identification of key features
-
In this study, a total of 22 flavonoids were tested for their HDAC inhibitory activity using fluorimetric and BRET-based assays. Four aurones were found to be active in both assays and showed IC50 values below 20 μM in the enzymatic assay. Molecular modelling revealed that the presence of hydroxyl groups was responsible for good compound orientation within the isoenzyme catalytic site and zinc chelation.
- Zwick, Vincent,Chatzivasileiou, Alkiviadis-Orfefs,Deschamps, Nathalie,Roussaki, Marina,Simes-Pires, Claudia A.,Nurisso, Alessandra,Denis, Iza,Blanquart, Christophe,Martinet, Nadine,Carrupt, Pierre-Alain,Detsi, Anastasia,Cuendet, Muriel
-
supporting information
p. 5497 - 5501
(2014/12/12)
-
- Copper-catalyzed intramolecular tandem reaction of (2-halogenphenyl)(3- phenyloxiran-2-yl)methanones: Synthesis of (Z)-aurones
-
A convenient and efficient method for the copper-catalyzed synthesis of (Z)-aurones via intramolecular tandem reaction of (2-halogenphenyl)(3- phenyloxiran-2-yl)methanones is reported. Moreover, a plausible mechanism for the formation of (Z)-aurones is proposed. This is the first report on the synthesis of (Z)-aurones through copper-catalyzed Ullmann coupling reaction employing epoxides as substrates.
- Weng, Yiyi,Chen, Qixu,Su, Weike
-
p. 4218 - 4224
(2014/05/20)
-
- Natural and synthetic 2′-hydroxy-chalcones and aurones: Synthesis, characterization and evaluation of the antioxidant and soybean lipoxygenase inhibitory activity
-
A series of 2′-hydroxy-chalcones and their oxidative cyclization products, aurones, have been synthesized and tested for their antioxidant and lipoxygenase inhibitory activity. The natural product aureusidin (31) was synthesized in high yield by a new approach. An extensive structure-relationship study was performed and revealed that several chalcones and aurones possess an appealing pharmacological profile combining high antioxidant and lipid peroxidation activity with potent soybean LOX inhibition.
- Detsi, Anastasia,Majdalani, Maya,Kontogiorgis, Christos A.,Hadjipavlou-Litina, Dimitra,Kefalas, Panagiotis
-
experimental part
p. 8073 - 8085
(2010/03/24)
-
- Synthesis and insect antifeedant activity of aurones against spodoptera litura larvae
-
A series of aurones were prepared from various phenols via phenoxy acetic acids and coumaranones and evaluated for insect antifeedant activity against the common cutworm (Spodoptera litura). The naturally occurring aurone was most active at an ED50 of 0.12 μmol/cm2. The synthetic precursor, coumaranones, showed that the introduction of methoxyl and methyl groups to the benzene ring increased insect antifeedant activity. Similarly, the tested aurones showed that the introduction of methoxyl group to the A and/or B rings increased the insect antifeedant activity, but 4,5,6- and 3 ,4 ,5 -trisubstituted compounds did not show this activity in this test. The hydroxylation of aurones in the B ring should be disadvantageous for insect antifeedant activity against S. litura. Although the melting points did not correlate well with the insect antifeedant activity, compounds that were nearly inactive had high melting points. A significant correlation was noted between biological activity (pED50) and a hydrogen-bonding parameter calculated from the Rf value obtained from SiOH thin-layer chromatography and a lipophilicity parameter (log k) calculated from the retention time in ODS high-performance liquid chromatography. The respective correlation coefficients (r) were -0.83 and -0.70. The introduction of alkoxy and alkyl groups along with adequate hydrogen bonding seems to contribute to the antifeedant activity of the compounds tested.
- Morimoto, Masanori,Fukumoto, Hiromi,Nozoe, Toki,Hagiwara, Ai,Komai, Koichiro
-
experimental part
p. 700 - 705
(2009/10/01)
-
- Dimethyldioxirane epoxidation of aurones and isoflavones
-
The synthesis of the corresponding epoxides 2 and 4 by epoxidation of aurones (2-benzylidenebenzofuran-3(2H)-ones, 1) and isoflavones (3-aryl-4H-1-benzopyran-4-ones, 3) with dimethyldioxirane at subambient temperatures is reported. These acid- and base-se
- Adam,Hadjiarapoglou,Levai
-
p. 436 - 438
(2007/10/02)
-
- Cyclodehydrogenation of 2'-Hydroxychalcones with DDQ: A Simple Route for Flavones and Aurones
-
The oxidation of 2'-hydroxychalcones with 2,3-dichloro-5,6-dicyano-p-benzoquinone provides a useful synthetic route for flavones and aurones.
- Imafuku, Kimiaki,Honda, Masaaki,McOmie, J. F. W.
-
p. 199 - 201
(2007/10/02)
-