Search

Your search keyword '"Zang, Hongjun"' showing total 113 results
Start Over Author "Zang, Hongjun"
113 results on '"Zang, Hongjun"'

16. Cleavage of non-polar C(sp2)‒C(sp2) bonds in cycloparaphenylenes via electric field-catalyzed electrophilic aromatic substitution.

Author

Lin, Junfeng, Lv, Yaxin, Song, Kai, Song, Xuwei, Zang, Hongjun, Du, Pingwu, Zang, Yaping, and Zhu, Daoben

Abstract

Electrophilic aromatic substitution (EAS) is one of the most fundamental reactions in organic chemistry. Using an oriented external electric field (OEEF) instead of traditional reagents to tune the EAS reactivity can offer an environmentally friendly method to synthesize aromatic compounds and hold the promise of broadening its scope. Despite these advantages, OEEF catalysis of EAS is difficult to realize, due to the challenge of microscopically orienting OEEF along the direction of electron reorganizations. In this work, we demonstrate OEEF-catalyzed EAS reactions in a series of cycloparaphenylenes (CPPs) using the scanning tunneling microscope break junction (STM-BJ) technique. Crucially, the unique radial π-conjugation of CPPs enables a desired alignment for the OEEF to catalyze the EAS with Au STM tip (or substrate) acting as an electrophile. Under mild conditions, the OEEF-catalyzed EAS reactions can cleave the inherently inert C(sp2)-C(sp2) bond, leading to high-yield (~97%) formation of linear oligophenylenes terminated with covalent Au-C bonds. These results not only demonstrate the feasibility of OEEF catalysis of EAS, but also offer a way of exploring new mechanistic principles of classic organic reactions aided by OEEF.Novel methodologies for cleaving inherently inert C(sp2)‒ C(sp2) bonds are desirable. Here, the authors report the use of an oriented electric field to cleave C(sp2)‒ C(sp2) in cycloparaphenylenes via electrophilic aromatic substitution. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

23. Efficient conversion of N-acetyl-D-glucosamine into nitrogen-containing compound 3-acetamido-5-acetylfuran using amino acid ionic liquid as the recyclable catalyst

Author

Kang Wang, Shang Zhen, Jing Lou, Wang Jiao, Zang Hongjun, Huanxin Li, and Jiao Shuolei

Subjects
Environmental Engineering, 010504 meteorology & atmospheric sciences, chemistry.chemical_element, 010501 environmental sciences, Raw material, 01 natural sciences, Pollution, Chloride, Nitrogen, Catalysis, chemistry.chemical_compound, Monomer, chemistry, Yield (chemistry), Ionic liquid, medicine, Environmental Chemistry, Organic chemistry, Boron, Waste Management and Disposal, 0105 earth and related environmental sciences, medicine.drug
Abstract

Chitin is the most widely distributed oceanic biomass resources. Its monomer unit, N-acetyl-D-glucosamine (NAG), contains precious atomic nitrogen and represents a potential feedstock for the manufacture of regenerative organic nitrogen chemicals. Herein, the conversion of NAG to the platform chemical, 3-acetamido-5-acetylfuran (3A5AF), catalyzed by amino acid ionic liquids, was investigated. The reaction, catalyzed by a very small amount of glycine chloride ionic liquid without any additives, could yield 43.22% 3A5AF in 10 min. By adding CaCl2, a higher yield up to 52.61% was obtained. This work demonstrated the conversion of chitin biomass to 3A5AF in higher yield without using a boron-based catalyst for the first time. Moreover, the ionic liquid catalyst exhibited excellent recyclability, and afforded 43.22–36.59% yield over during eight cycles. This research provides new and green procedures to convert shellfish fishery waste into value-added platform chemicals.

Published
2020

37. An efficient method for synthesis of 3-arylbenzo[ f]quinoline-1,2-dicarboxylates catalyzed by SnCl.

Author

Yan, Qing, Zang, Hongjun, Feng, Jiaxuan, Li, Mingguang, Yang, Danni, Lu, Hai, and Cheng, Bowen

Subjects
NAPHTHALENE, NAPHTHYL compounds, BUSPIRONE, ACETONITRILE, NITRILES
Abstract

A wide variety of 3-arylbenzo[ f]quinoline-1,2-dicarboxylates and their dehydro derivatives have been synthesized by one-pot, three-component reaction of an aromatic aldehyde, naphthalene-2-amine, and dimethyl but-2-ynedioate in the presence of SnCl under reflux in acetonitrile. This procedure has several advantages, for example high yield, short reaction time, easy work-up, little pollution, and low price of the catalyst. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results