574-00-5Relevant academic research and scientific papers
Pentaquinone based probe for nanomolar detection of zinc ions: Chemosensing ensemble as an antioxidant
Bhalla, Vandana,Roopa,Kumar, Manoj
, p. 975 - 980 (2013)
A pentaquinone based compound 3a has been synthesized which undergoes significant fluorescence enhancement in the presence of Zn2+ ions with a detection limit up to nanomolar range in THF. Further, the zinc ensemble of 3a is evaluated for its anti-oxidizing property which is better than commercially available antioxidants. The Royal Society of Chemistry 2013.
Synthesis and biology of bis-xylosylated dihydroxynaphthalenes
Johnsson, Richard,Mani, Katrin,Ellervik, Ulf
, p. 2868 - 2877 (2007)
The 10 analogous bis-xylosylated dihydroxynaphthalenes have been synthesized and their chemical and biological properties investigated. The yield of the xylosylation reactions can be correlated to the electrostatic potential, and thus to the nucleophilicity, for the oxygen atoms of the dihydroxynaphthalenes. The bis-xylosylated compounds were more stable compared to the mono-xylosylated ones. They initiate priming of glycosaminoglycan chains to less extent but the priming proceeds in two directions. Contrary to the mono-xylosylated analogs, the tested compounds did not show any antiproliferative properties.
Photochemical Reaction Between 1,2-Naphthoquinone and Adenine in Binary Water-Acetonitrile Solutions
Zhou, Qiaohui,Wei, Yaxiong,Liu, Xiang,Chen, Lin,Zhou, Xiaoguo,Liu, Shilin
, p. 61 - 68 (2018)
The photochemical reaction between 1,2-naphthoquinone (NQ) and adenine was investigated using nanosecond time-resolved laser flash photolysis. With photolysis at 355?nm, the lowest triplet state T1 of NQ was produced via intersystem crossing from its singlet excited state. The triplet-triplet absorption of the state contributes three bands of transient spectra at 374, 596 and 650?nm, respectively, in pure acetonitrile and binary water-acetonitrile solutions. In the presence of adenine, the observation of A .+ (at 363?nm) and NQ+H. radical (at 343 and 485?nm) indicates a multistep mechanism of electron transfer process followed by a proton transfer between 3NQ* and adenine. By fitting with the Stern-Volmer relationship, the quenching rate constant kq of 3NQ* by adenine in binary water-acetonitrile solutions (4/1, volume ratio, v/v) is determined as 1.66?×?109?m?1?s?1. Additionally, no spectral evidence confirms the existence of electron transfer between 3NQ* with thymine, cytosine and uracil.
Pd-Au-Y as Efficient Catalyst for C-C Coupling Reactions, Benzylic C-H Bond Activation, and Oxidation of Ethanol for Synthesis of Cinnamaldehydes
Sharma, Mukesh,Das, Biraj,Baruah, Manash J.,Biswas, Subir,Roy, Subhasish,Hazarika, Anil,Bhargava, Suresh K.,Bania, Kusum K.
, p. 5860 - 5875 (2019/06/17)
Pd-Au nanoalloy supported on zeolite-Y (Pd-Au-Y) matrix was found to be an effective catalyst for C-Cl bond activation and oxidative coupling of 2-naphthol, leading to the formation of various biaryl products and 1,1′-bi-2-naphthol, BINOL. The same catalyst was also highly efficient for selective oxidation of benzylic alcohols to benzaldehydes. Cinnamaldehydes were obtained directly from benzaldehydes by aldol condensation with acetaldehyde generated in situ by partial oxidation of ethanol in the presence of Pd-Au-Y catalyst at 120 °C under basic condition. The biaryl products were also obtained directly from benzylic alcohols in a one-pot system by reacting with phenylboronic acid. The formation of biaryls from benzylic alcohols was believed to occur via one-pot benzylic C-H and C-Cl bond activation. A high % yield of biaryls, BINOL, aldehydes, and cinnamaldehydes was obtained by performing different reactions using the single Pd-Au-Y catalyst. The strong interaction of chloro-benzylic alcohol was predominantly located at active gold species. X-ray photoelectron and diffuse reflectance spectroscopic studies revealed the strong interaction between Pd and Au particles. Electrochemical studies provided proper evidence for the individual role of the nanoparticles (NPs) in one-pot synthesis of biaryls from benzylic alcohols.
1-Methyl-1,4-cyclohexadiene as a Traceless Reducing Agent for the Synthesis of Catechols and Hydroquinones
Baschieri, Andrea,Amorati, Riccardo,Valgimigli, Luca,Sambri, Letizia
, p. 13655 - 13664 (2019/10/28)
Pro-aromatic and volatile 1-methyl-1,4-cyclohexadiene (MeCHD) was used for the first time as a valid H-atom source in an innovative method to reduce ortho or para quinones to obtain the corresponding catechols and hydroquinones in good to excellent yields. Notably, the excess of MeCHD and the toluene formed as the oxidation product can be easily removed by evaporation. In some cases, trifluoroacetic acid as a catalyst was added to obtain the desired products. The reaction proceeds in air and under mild conditions, without metal catalysts and sulfur derivatives, resulting in an excellent and competitive method to reduce quinones. The mechanism is attributed to a radical reaction triggered by a hydrogen atom transfer from MeCHD to quinones, or, in the presence of trifluoroacetic acid, to a hydride transfer process.
Synthesis of α-oxygenated ketones and substituted catechols via the rearrangement of N-enoxy- and N-aryloxyphthalimides
Kroc, Michelle A.,Patil, Aditi,Carlos, Anthony,Ballantine, Josiah,Aguilar, Stephanie,Mo, Dong-Liang,Wang, Heng-Yen,Mueller, Daniel S.,Wink, Donald J.,Anderson, Laura L.
, p. 4125 - 4137 (2017/06/29)
A common approach to the synthesis of α-oxygenated carbonyl compounds and catechols is the treatment of a carbonyl compound or a phenol with an electrophilic oxygen source. As an alternative approach to these important structures, formal [3,3]-rearrangements of N-enoxyphthalimides, N-enoxyisoindolinones, and N-aryloxyphthalimides have been explored. When used in combination with an initial Chan-Lam coupling, these transformations facilitate the dioxygenation of alkenylboronic acids for the synthesis of α-oxygenated ketones and the dioxygenation of arylboronic acids for the synthesis of catechols. The rearrangements of N-enoxyisoindolinones have also been shown to be diastereoselective.
On the redox reaction of 1,2-bis(diphenylphosphino) alkanes toward o -, and p-quinones
Boulos, Leila S.,Ewies, Ewies F.,Fahmy, Amin F. M.
, p. 726 - 738 (2013/07/26)
The reaction of 1,2-bis(diphenylphosphino)ethane with substituted o-benzo-quinones afforded new bis(6-hydroxycyclohexa-2,4-dienone) derivatives. Treatment of the same reagent with o-naphthoquinone, phenanthrenequinone, and acenaphthenequinone gave the res
Organocatalytic Dakin oxidation by nucleophilic flavin catalysts
Chen, Shuai,Hossain, Mohammad S.,Foss, Frank W.
supporting information; experimental part, p. 2806 - 2809 (2012/08/07)
Flavin catalysts perform the first organocatalytic Dakin oxidation of electron-rich arylaldehydes to phenols under mild, basic conditions. Catechols are readily prepared, and the oxidation of 2-hydroxyacetophenone was achieved. Aerobic oxidation is displayed in the presence of Zn(0) as a reducing agent. This reactivity broadens the scope of biomimetic flavin catalysis in the realm of nucleophilic oxidations, providing a framework for mechanistic investigations for related oxidations, such as the Baeyer-Villiger oxidation and Weitz-Scheffer epoxidation.
A triphenylene based zinc ensemble as an oxidation inhibitor
Bhalla, Vandana,Arora, Harshveer,Dhir, Abhimanew,Kumar, Manoj
scheme or table, p. 4722 - 4724 (2012/06/01)
The zinc complex of a new triphenylene based receptor is evaluated for its anti-oxidant activity which is better in comparison to that of commercially available anti-oxidants.
Aerobic organocatalytic oxidation of aryl aldehydes: Flavin catalyst turnover by Hantzsch's ester
Chen, Shuai,Foss, Frank W.
supporting information, p. 5150 - 5153,4 (2020/09/15)
The first Dakin oxidation fueled by molecular oxygen as the terminal oxidant is reported. Flavin and NAD(P)H coenzymes, from natural enzymatic redox systems, inspired the use of flavin organocatalysts and a Hantzsch ester to perform transition-metal-free, aerobic oxidations. Catechols and electron-rich phenols are achieved with as low as a 0.1 mol % catalyst loading, 1 equiv of Hantzsch ester, and O2 or air as the stoichiometric oxidant source.
