- Synthesis and Photoswitching Properties of Bioinspired Dissymmetric I-Pyrone, an Analogue of Cyclocurcumin
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Cyclocurcumin (CC), a turmeric curcuminoid with potential therapeutic properties, is also a natural photoswitch that may undergo E/Z photoisomerization under UV light. To be further exploited in relevant biological applications, photoactivation under near-infrared (NIR) irradiation is required. Such requirement can be met through opportune chemical modifications, by favoring two-photon absorption (TPA) probability. Herein, a general and efficient synthesis of a biomimetic 2,6-disubstituted-δ-pyrone analogue of CC is described, motivated by the fact that molecular modeling previews an order of magnitude increase of its NIR TPA compared to CC. Three retrosynthetic pathways have been identified (i) via an aryl-oxazole intermediate or via aryl-diynone through (ii) a bottom-up or (iii) a top-down approach. While avoiding the passage through unstable synthons or low-yield intermediate reactions, only the latest approach could conveniently afford the 2,6-disubstituted-I-pyrone analogue of CC, in ten steps and with an overall yield of 18%. The photophysical properties of our biomimetic analogue have also been characterized showing an improved photoisomerization yield over the parent natural compound. The potentially improved nonlinear optical properties, as well as enhanced stability, may be correlated to the enforcement of the planarity of the pyrone moiety leading to a quadrupolar D-π-A-π-D system.
- Pecourneau, Jérémy,Losantos, Raúl,Monari, Antonio,Parant, Stéphane,Pasc, Andreea,Mourer, Maxime
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p. 8112 - 8126
(2021/06/30)
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- DBU-Mediated Synthesis of Aryl Acetylenes or 1-Bromoethynylarenes from Aldehydes
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Two well known synthetic organic reactions Ramirez olefination and Corey-fuchs reactions are integrated in one-pot sequential manner for the synthesis of arylacetylenes and 1,3-enynes starting directly from commercially available aldehydes. The bicyclic amidine 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) along with additive NaOH not only exclusively afforded the terminal alkynes directly from the aldehydes, but also enhanced the reaction rate. The dynamic nature of DBU also facilitated the isolation of 1-bromoalkynes intermediate products. Selection of additive from NaOH and H2O served as a switch for the synthesis of terminal alkyne and 1-bromoalkynes, respectively. (Figure presented.).
- Thummala, Yadagiri,Karunakar, Galla V.,Doddi, Venkata Ramana
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supporting information
p. 611 - 616
(2019/01/04)
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- Conjugation of Hydroxytyrosol with Other Natural Phenolic Fragments: From Waste to Antioxidants and Antitumour Compounds
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Hydroxytyrosol, a natural polyphenol that can be extracted from olive mill waste waters, was converted into a series of more complex and lipophilic analogues by conjugation with other naturally derived (poly)phenolic fragments. Ether and triazole linkers were employed. A small library of compounds was prepared, stressing step economy and operational simplicity. Some of these substances were proven to have activity equal or superior to that of the parent hydroxytyrosol in radical scavenging assays as well as in cytotoxicity tests against tumour cells.
- Tassano, Erika,Alama, Angela,Basso, Andrea,Dondo, Giancarlo,Galatini, Andrea,Riva, Renata,Banfi, Luca
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p. 6710 - 6726
(2015/10/29)
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- Total synthesis of moniliformediquinone and calanquinone A as potent inhibitors for breast cancer
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The first synthesis of moniliformediquinone has been achieved in which the longest linear sequence is only nine steps. The synthesis proceeds in 23% overall yield from commercially available 2,4,5-trimethoxybenzaldehyde. The key transformations include a
- Thangaraj, Shankar,Tsao, Wen-Shing,Luo, Yi-Wei,Lee, Yean-Jang,Chang, Chia-Fu,Lin, Chun-Cheng,Uang, Biing-Jiun,Yu, Chia-Chun,Guh, Jih-Hwa,Teng, Che-Ming
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p. 6166 - 6172
(2011/09/19)
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- Rapid synthesis of triazole-modified resveratrol analogues via click chemistry
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Resveratrol is a phytoalexin able to display an array of biological activities. We decided to replace the double bond with a triazole ring using the archetypical click reaction: the Huisgen [3 + 2] cycloaddition. Seventy-two triazole derivatives were synt
- Pagliai, Francesca,Pirali, Tracey,Del Grosso, Erika,Di Brisco, Riccardo,Tron, Gian Cesare,Sorba, Giovanni,Genazzani, Armando A.
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p. 467 - 470
(2007/10/03)
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- Synthesis, thermal reactivity and structure of 1,2-bis(4-hydroxy-3- methoxyphenylethynyl)benzene
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The crystal structure of the new enediyne 3 was determined by X-ray diffraction. 3 crystallizes in the orthorhombic space group Pbca (No. 61) with a = 12.7148(9) A, b = 7.4872(8) A, c = 38.890(4) A, α = β = γ = 90° and Z = 8. The three-dimensional structu
- Schmittel, Michael,Morbach, Guido,Schenk, Wolfdieter A.,Hagel, Michael
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p. 373 - 379
(2007/10/03)
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- Synthesis of symmetrical bis-alkynyl or alkyl pyridine and thiophene derivatives and their antiangiogenic activities
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Fourteen symmetrical bis-alkynyl pyridine and thiophene derivatives were synthesized and their antiangiogenic activity was evaluated with the proliferation and tube formation inhibitory activity on the human umbilical vein endothelial cells (HUVEC). Compo
- Ahn, Chan Mug,Shin, Woon-Seob,Woo, Ho Bum,Lee, Seokjoon,Lee, Hyean-Woo
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p. 3893 - 3896
(2007/10/03)
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