4010-33-7Relevant academic research and scientific papers
Electrochemical Aerobic Oxidative Cleavage of (sp3)C-C(sp3)/H Bonds in Alkylarenes
Liu, Shuai,Liu, Zhong-Quan,Shen, Tong,Shen, Xu,Wang, Nengyong,Wu, Jintao,Yang, Le,Zhao, Jianyou
, p. 3286 - 3295 (2022/03/14)
An electrochemistry-promoted oxidative cleavage of (sp3)C-C(sp3)/H bonds in alkylarenes was developed. Various aryl alkanes can be smoothly converted into ketones/aldehydes under aerobic conditions using a user-friendly undivided cell setup. The features of air as oxidant, scalability, and mild conditions make them attractive in synthetic organic chemistry.
In vitro photoprotective evaluation and development of novel nanoemulsion with chromone derivative
Amparo, Tatiane R.,Antunes, Amanda S.,Cazati, Thiago,Diogo, Gabriela M.,Dos Santos, Viviane M. R.,Gouveia, Ana Paula,Penido, Ricardo G.,Perasoli, Fernanda B.,Sousa, Lucas R. D.,Taylor, Jason G.,Vieira, Paula M. A.,dos Santos, Orlando D. H.
, p. 1813 - 1821 (2021/08/05)
Chromone derivatives exhibiting high absorbance values in the UVA/UVB region were synthesized, and their photoprotective properties were evaluated. Chromones were prepared according to known literature procedures and characterized by high resolution mass
Copper-catalyzed chemoselective oxidative o-aroylation of 2-acetylphenols, alkyl salicylates and 1,3-dicarbonyl compounds using styrene derivatives
Kumar, Upendra,Sharma, Ajay,Kumar, Naveen,Pandey, Satyendra Kumar
, (2021/03/03)
A novel copper-catalyzed chemoselective oxidative O-aroylation of 2-acetylphenols, alkyl salicylates and 1,3-dicarbonyl compounds with a wide range of styrene derivatives are described. This approach provides an efficient chemoselective preparation of phenol, alkyl salicylate and enol esters in good to excellent yields. This method represents an alternative protocol for the classical esterification reactions.
Chapter Open for the Excited-State Intramolecular Thiol Proton Transfer in the Room-Temperature Solution
Chang, Chao-Che,Chen, Chao-Tsen,Chou, Pi-Tai,Huang, Chun-Hao,Li, Elise Y.,Liao, Yu-Chan,Liu, Yi-Hung,Liu, Zong-Ying,Meng, Fan-Yi,Wang, Chun-Hsiang
supporting information, p. 12715 - 12724 (2021/08/30)
We report here, for the first time, the experimental observation on the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton in room-temperature solution. This phenomenon is demonstrated by a derivative of 3-thiolflavone (3TF), namely, 2-(4-(diethylamino)phenyl)-3-mercapto-4H-chromen-4-one (3NTF), which possesses an - S - H···O= intramolecular H-bond (denoted by the dashed line) and has an S1 absorption at 383 nm. Upon photoexcitation, 3NTF exhibits a distinctly red emission maximized at 710 nm in cyclohexane with an anomalously large Stokes shift of 12 230 cm-1. Upon methylation on the thiol group, 3MeNTF, lacking the thiol proton, exhibits a normal Stokes-shifted emission at 472 nm. These, in combination with the computational approaches, lead to the conclusion of thiol-type ESIPT unambiguously. Further time-resolved study renders an unresolvable (180 fs) ESIPT rate for 3NTF, followed by a tautomer emission lifetime of 120 ps. In sharp contrast to 3NTF, both 3TF and 3-mercapto-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one (3FTF) are non-emissive. Detailed computational approaches indicate that all studied thiols undergo thermally favorable ESIPT. However, once forming the proton-transferred tautomer, the lone-pair electrons on the sulfur atom brings non-negligible nπ? contribution to the S1′ state (prime indicates the proton-transferred tautomer), for which the relaxation is dominated by the non-radiative deactivation. For 3NTF, the extension of π-electron delocalization by the diethylamino electron-donating group endows the S1′ state primarily in the ππ? configuration, exhibiting the prominent tautomer emission. The results open a new chapter in the field of ESIPT, covering the non-canonical sulfur intramolecular H-bond and its associated ESIPT at ambient temperature.
Synthesis of Spiro[benzofuran-2,2'-benzo[b]thiophene]-3,3'-diones via PIDA/CuBr-Mediated Spirocyclization
Du, Yunfei,Li, Xuemin,Liang, Huiyuan,Sun, Fengxia,Wang, Donghua,Wang, Xi,Yang, Yaxin O,Zhang, Jingran
, p. 6563 - 6569 (2020/11/16)
A phenyliodine(III) diacetate (PIDA)/CuBr-mediated construction of the novel 3H,3'H-spiro[benzofuran-2,2'-benzo[b]thiophene]-3,3'-dione skeleton was realized from the reaction of (Z)-3-hydroxy-1-(2-hydroxyphenyl)-3-(2-halogenphenyl)prop-2-en-1-ones with p
Synthesis, photophysical and electrochemical properties of novel and highly fluorescent difluoroboron flavanone β-diketonate complexes
Paez, Elida Betania Ariza,Curcio, Sergio,Neme, Natália P.,Matos, Matheus J. S.,Correa, Rodrigo S.,Pereira, Fabio Junio,Hilário, Flaviane Francisco,Cazati, Thiago,Taylor, Jason Guy
supporting information, p. 14615 - 14631 (2020/10/02)
Difluoroboron β-diketonates complexes are highly luminescent with extensive properties such as their fluorescence both in solution and in solid state and their high molar extinction coefficients. Due to their rich optical properties, these compounds have been studied for their applications in organic electronics such as in self-assembly and applications in biosensors, bio-imaging and optoelectronic devices. The easy and fast synthesis of difluoroboron β-diketonate (BF2dbm) complexes makes their applications even more attractive. Although many different types of difluoroboron β-diketonates complexes have been studied, the cyclic flavanone analogues of these compounds have never been reported in the literature. Therefore, the present work aims to synthesize difluouroboron flavanone β-diketonate complexes, study their photophysical and electrochemical properties and assess their suitability for applications in optoelectronic devices. The synthesis was based on a Baker-Venkataraman reaction which initially provided substituted diketones, which were subsequently reacted with aldehydes to afford the proposed flavanones. The complexation was achieved by reacting flavanones and BF3·Et2O and in total 9 novel compounds were obtained. A representative difluoroboron flavanone complex was subjected to single crystal X-ray diffraction to unequivocally confirm the chemical structure. A stability study indicated only partial degradation of these compounds over a few days in a protic solvent at elevated temperatures. Photophysical studies revealed that the substituent groups and the solvent media significantly influence the electrochemical and photophysical properties of the final compounds, especially the molar absorption coefficient, fluorescence quantum yields, and the band gap. Moreover, the compounds exhibited a single excited-state lifetime in all studied solvents. Computational studies were employed to evaluate ground and excited state properties and carry out DFT and TDDFT level analysis. These studies clarify the role of each state in the experimental absorption spectra as well as the effect of the solvent.
Trypanocidal activity of flavanone derivatives
Andrade, Josimara Souza,Diogo, Gabriela Maciel,Dos Santos, Viviane Martins Rebello,Murta, Silvane Maria Fonseca,Sales, Policarpo Ademar,Taylor, Jason Guy
, (2020/01/28)
Chagas disease, also known as American trypanosomiasis, is classified as a neglected disease by the World Health Organization. For clinical treatment, only two drugs have been on the market, Benznidazole and Nifurtimox, both of which are recommended for use in the acute phase but present low cure rates in the chronic phase. Furthermore, strong side effects may result in discontinuation of this treatment. Faced with this situation, we report the synthesis and trypanocidal activity of 3-benzoyl-flavanones. Novel 3-benzoyl-flavanone derivatives were prepared in satisfactory yields in the 3-step synthetic procedure. According to recommended guidelines, the whole cell-based screening methodology was utilized that allowed for the simultaneous use of both parasite forms responsible for human infection. The majority of the tested compounds displayed promising anti-Trypanosoma cruzi activity and the most potent flavanone bearing a nitrofuran moiety was more potent than the reference drug, Benznidazole.
Novel Bifunctionalization of Activated Methylene: Base-Promoted Trifluoromethylthiolation of β-Diketones with Trifluoromethanesulfinyl Chloride
Sun, Dong-Wei,Jiang, Min,Liu, Jin-Tao
supporting information, p. 10797 - 10802 (2019/07/03)
A novel bifunctionalization of activated methylene was achieved successfully through the base-promoted trifluoromethylthiolation of β-diketones or β-ketoesters with trifluoromethanesulfinyl chloride. A series of α-trifluoromethylthiolated α-chloro-β-diketones and α-chloro-β-ketoesters were obtained in moderate to good yields under mild conditions. When β-diketones containing a phenyl group with a hydroxyl or amino substituent at the ortho position were used as substrates, intramolecular trifluoromethylthiolation/cyclization reaction took place to give the corresponding cyclic products. Furthermore, the protocol could be extended to perfluoroalkylthiolation with the sodium perfluoroalkanesulfinate/POCl3 system. On the basis of experimental results, plausible mechanisms are proposed.
Soft-enolization Baker-Venkataraman Rearrangement Enabled Total Synthesis of Dirchromones and Related 2-Substituted Chromones
St-Gelais, Alexis,Alsarraf, Jér?me,Legault, Jean,Gauthier, Charles,Pichette, André
supporting information, p. 7424 - 7428 (2019/01/03)
A seven-step total synthesis of the original scaffold of cytotoxic dirchromones involving an unprecedented soft-enolization Baker-Venkataraman rearrangement was designed. The methodology enabled access to naturally occurring dirchromone 1 (21% overall yield) at gram-scale, which was screened for cytotoxicity against 13 cancer cell lines. The scope of the soft-enolization Baker-Venkataraman rearrangement encompasses diversely substituted dirchromones, including flavonoids, 2-styrylchromones, and 2-phenylethylchromones.
Synthesis of 3,5-diarylisoxazole derivatives and evaluation of in vitro trypanocidal activity
De Souza, Aline A. N.,Xavier, Viviane F.,Coelho, Gleicekelly S.,Sales Junior, Policarpo A.,Romanha, Alvaro J.,Murta, Silvane M. F.,Carneiro, Claudia M.,Taylor, Jason G.
, p. 269 - 277 (2017/12/08)
Chagas disease is included in the neglected tropical diseases list and is endemic to 21 Latin American countries. The two drugs currently available for treating Chagas disease are nifurtimox and benznidazole and both result in many significant side effects. The study describes the synthesis and biological evaluation of 3,5-disubstituted isoxazoles. Isoxazoles were obtained by reaction of flavones and hydroxylamine and either alkylated at the free hydroxyl group and/or nitrated at the isoxazole ring. These compounds were evaluated for their in vitro anti-Trypanosoma cruzi activity against trypomastigote and amastigote forms of the parasite in T. cruzi-infected cell lineages. Benznidazole was used as a reference compound for the in vitro assay and mammalian L929 cells were employed to evaluate cytotoxicity. A majority of the compounds tested were very active and the most active isoxazole against amastigote and trypomastigotes of T. cruzi was slightly more potent than the current medicine benznidazole.
