نتایج جستجو برای: electron withdrawing

تعداد نتایج: 310077  

Journal: :The Journal of organic chemistry 2017
Keying Ding Shi Xu Rajeh Alotaibi Keshav Paudel Eric W Reinheimer Jessie Weatherly

We report here the first systematic study of nickel-catalyzed decarbonylation of aromatic aldehydes under relatively mild conditions. Aldehydes with electron donating groups at para and ortho positions are generally successful with our method. For aldehydes with electron-withdrawing groups, significantly higher yields were achieved for ortho-substituted substrates than para ones, probably due t...

2013
Krishna Pada Bhabak Debasish Bhowmick Govindasamy Mugesh

Catalytic activity of a series of potent amideand amine-based organoselenium compounds are studied in the presence of various aromatic thiols having electron donating and electron withdrawing substituents on the phenyl ring. This study suggests that the antioxidant activities of the synthetic GPx mimics can be significantly increased by the incorporation of a suitable electron donating group on...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2002
Christopher A Hunter Caroline M R Low Carmen Rotger Jeremy G Vinter Cristiano Zonta

A synthetic supramolecular complex has been adapted to quantify cation-pi interactions in chloroform by using chemical double-mutant cycles. The interaction of a pyridinium cation with the pi-face of an aromatic ring is found to be very sensitive to the pi-electron density. Electron-donating substituents lead to a strong attractive interaction (-8 kJ/mol(-1)), but electron-withdrawing groups le...

Journal: :International Journal For Multidisciplinary Research 2023

A straightforward synthesis of phenols from aryl boronic acids has been demonstrated using benzoic acid as a catalyst. Variety arylboronic bearing electron rich and withdrawing substituents gave the respective in good yields.

2013
Bingcheng Hu Chengguo Sun Quanzhi Deng Zuliang Liu

A series of cobalt porphyrins derived from hemin was prepared as cytochrome P450 models. Effects of substituents at the cobalt deuteroporphyrin-propionate side chains are investigated in oxidation of toluene with air to benzaldehyde and benzyl alcohol without the use of solvent and sacrificial co-reductant. The catalytic activity of cobalt porphyrins depends on the type of substituents. When th...

Navnath Gunjal Somnath Gholap,

Thiamine hydrochloride (Vitamin-B1) has been utilized as an effective biodegradable catalyst for the one pot synthesis of polyhydroquinoline derivatives via four component reaction of dimedone, aldehyde, ethylacetoacetate and ammonium acetate in ethanol under mild conditions. The method presented here offers several advantages over reported procedures in terms of environmentally benign catalyti...

A simple, highly efficient and green procedure for the condensation of o-phenylenediamines with 1, 2-dicarbonyl compounds in the presence of vitamin C, as an inexpensive organocatalyst, is described. Using this method, variety of quinoxaline derivatives with different electron releasing and electron withdrawing substituents, are produced in high to excellent yields at room temperature in ethano...

A new organocatalyzed method is developed for Baylis–Hillman reactions of cyclohex-2-enone with various aromatic aldehydes in the presence of water and catalytic quantities of triethylamine. All reactions take place at room temperature and relatively good yields of various products are obtained within a time frame which does not exceed 24 hours. The mild reaction conditions used in the present ...

Journal: :Chemistry 2005
Nathan W Luedtke Qi Liu Yitzhak Tor

The electronic structure of the common intercalating agent ethidium bromide (3,8-diamino-5-ethyl-6-phenylphenanthridinium bromide) is dominated by an interplay of electron donating and withdrawing effects mediated by its nitrogen atoms. X-ray crystallography, UV/Vis and IR absorption, fluorescence emission, and NMR spectroscopy are used to probe the electronic properties of the phenanthridinium...

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