38527-54-7Relevant academic research and scientific papers
Transition-Metal-Free Synthesis of Heterobiaryls through 1,2-Migration of Boronate Complex
Paul, Swagata,Das, Kanak Kanti,Manna, Samir,Panda, Santanu
supporting information, p. 1922 - 1927 (2020/02/04)
The synthesis of a diverse range of heterobiaryls has been achieved by a transition-metal-free sp2–sp2 cross-coupling strategy using lithiated heterocycle, aryl or heteroaryl boronic ester and an electrophilic halogen source. The construction of heterobiaryls was carried out through electrophilic activation of the aryl–heteroaryl boronate complex, which triggered 1,2-migration from boron to the carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield. A comprehensive 11B NMR study has been conducted to support the mechanism. The cross coupling between two nucleophilic cross coupling partners without transition metals reveals a reliable manifold to procure heterobiaryls in good yields. Various heterocycles like furan, thiophene, benzofuran, benzothiophene, and indole are well tolerated. Finally, we have successfully demonstrated the gram scale synthesis of the intermediates for an anticancer drug and OLED material using our methodology.
Perylenequinonoid-catalyzed photoredox activation for the direct arylation of (het)arenes with sunlight
Zhang, Shiwei,Tang, Zhaocheng,Bao, Wenhao,Li, Jia,Guo, Baodang,Huang, Shuping,Zhang, Yan,Rao, Yijian
supporting information, p. 4364 - 4369 (2019/05/10)
Naturally occurring perylenequinonoid pigments (PQPs) have attracted considerable attention owing to their excellent properties of photosensitization. They have been widely investigated as an aspect of photophysics and photobiology. However, their applications in photocatalysis are yet to be explored. We report here that sunlight along with 1 mol% cercosporin, which is one of the perylenequinonoid pigments, catalyzes the direct C-H bond arylation of (het)arenes by a photoredox process with good regioselectivity and broad functional group compatibility. Furthermore, a gram-scale reaction with great conversions of substrates was achieved even by a cercosporin-containing supernatant without organic solvent extraction and purification after liquid fermentation. Thus we set up a bridge between microbial fermentation and organic photocatalysis for chemical reactions in a sustainable, environmentally friendly manner.
Synthesis of 2,5-Disubstituted Furans from Sc(OTf)3 Catalyzed Reaction of Aryl Oxiranediesters with γ-Hydroxyenones
Mondal, Keshab,Pan, Subhas Chandra
, p. 4415 - 4421 (2017/04/27)
A convenient synthesis of 2,5-disubstituted furan was developed by employing donor-acceptor oxiranes in a new reaction with γ-hydroxyenones. Sc(OTf)3 was found to be the best catalyst, and 2,5-disubstituted furans are obtained in moderate to good yields under mild reaction conditions. The scope of the reaction is quite decent, allowing for the synthesis of disubstituted furans having aryl and heteroaromatic groups.
Sodium Chloride Catalyzed Regioselective Trifluoromethylthiolation of Furans
Ernst, Johannes B.,Rakers, Lena,Glorius, Frank
supporting information, p. 260 - 268 (2016/12/24)
Here, we report the catalytic trifluoromethylthiolation of furans employing sodium chloride as an inexpensive, abundant and ecologically friendly catalyst. The developed method exhibits perfect regioselectivity and a high functional group tolerance. Furth
Palladium-Catalyzed Dearomatizing Alkoxydiarylation of Furan Rings by Coupling with Arylboronic Acids: Access to Polysubstituted Oxabicyclic Compounds
Li, Jiuyi,Lu, Lin,Pan, Qi,Ren, Yanwei,Liu, Bo,Yin, Biaolin
supporting information, p. 2001 - 2007 (2017/06/09)
We report a protocol for palladium-catalyzed dearomatizing alkoxydiarylation of furan rings via aerobic oxidative coupling between arylboronic acids and 5-aryl-2-hydroxyalkylfurans. This green protocol starting from furan derivatives, which can be sustainably sourced, provides rapid access to polysubstituted 2,3,3a,6a-tetrahydrofuro[3,2-b]furans and hexahydrofuro[3,2-b]furans, oxabicyclic frameworks that are shared by various natural products and synthetic molecules with important biological activities. (Figure presented.).
Gram-scale synthesis of aligned C3N4-polypyrrole heterojunction aerogels with tunable band structures as efficient visible and near infrared light-driven metal-free photocatalysts
Liu, Jian,Wang, Hao,Bai, Jinwei,Li, Tianrong,Yang, Yanmei,Peng, Yong,Wang, Baodui
, p. 24920 - 24928 (2017/12/15)
The assembly of aligned porous materials from simple building blocks is of widespread interest for engineering materials with enhanced and synergistic properties. To date, however, how to develop 3D heterojunction aerogels with aligned porosity based on 2D semiconductor materials and 1D conducting polymers for solar energy conversion in the visible and near-infrared (NIR) light region remains a significant challenge. Here a new class of gram-scale 3D aligned heterojunction aerogels of polypyrrole (PPy)/C3N4 nanosheets (NSs) were designed and synthesized by directional freezing of polypyrrole (PPy)/polyvinyl alcohol (PVA) and C3N4 NS aqueous suspension. The synthesis of aligned C3N4-PPy heterojunction aerogels can be achieved on a large scale. The formed aerogel expresses stable and uniform dispersion of the two building blocks, long-range channel aligned structures along the whole monolithic sample, and additional special complementary optical properties between PPy and C3N4 NSs. Based on the above unique structure and optical properties, this novel metal-free heterojunction aerogel exhibits excellent photocatalytic activity and long-term stability for direct arylation of heteroaromatics under visible and near infrared (NIR) light irradiation at room temperature, far exceeding those of the single- and two-component systems. Our work therefore not only provides a new approach to obtain aligned heterojunction aerogels based on metal free semiconductors but also paves a way to develop gram-scale aerogels as a new type of highly efficient visible and NIR light induced heterogeneous photocatalyst.
Interface coassembly of mesoporous MoS2 based-frameworks for enhanced near-infrared light driven photocatalysis
Zhi, Lihua,Zhang, Haoli,Yang, Zhengyin,Liu, Weisheng,Wang, Baodui
supporting information, p. 6431 - 6434 (2016/05/24)
The three-dimensional porous Fe3O4@Cu2-xS-MoS2 framework is reported for the first time. The as-prepared 3D framework exhibits good structural stability, high surface area, enhanced adsorption capacity to substrates, and strong absorption in the NIR range. As a result, such hybrid frameworks exhibit excellent NIR-light photocatalytic activity and stable cycling for the direct arylation of heteroaromatics at room temperature.
Unexpected dual role of titanium dioxide in the visible light heterogeneous catalyzed C-H arylation of heteroarenes
Zoller, Jochen,Fabry, David C.,Rueping, Magnus
, p. 3900 - 3904 (2015/06/16)
The direct arylation of heteroaromatics with an easily accessible and recyclable, heterogeneous TiO2 catalyst and visible light was developed. Electron-rich as well as electron-poor heteroarenes could be applied in this transformation, and the corresponding products were isolated in very good yields. Azoethers were detected as reactive intermediates, and the unexpected role of TiO2 in their formation as well as reaction was established.
Synthesis of 2-substituted furans by iron- and palladium-catalyzed coupling reactions
Haner, Jamie,Jack, Kelsey,Nagireddy, Jaipal,Raheem, Mohammed Abdul,Durham, Robin,Tam, William
experimental part, p. 731 - 738 (2011/04/24)
The synthesis of 2-substituted furans via palladium- and iron-catalyzed coupling utilizing 2-bromofuran is described. Whereas palladium-catalyzed Suzuki coupling effectively provided the corresponding aryl furans, little or no product was obtained by palladium-catalyzed coupling with various alkyl nucleophiles. Iron-catalyzed coupling proved effective for the synthesis of primary and secondary alkyl furans in modest yields and aryl furans in low yields. Georg Thieme Verlag Stuttgart New York.
Efficient procedure for the preparation of 2-bromofuran and its application in the synthesis of 2-arylfurans
Raheem, Mohammed-Abdul,Nagireddy, Jaipal R.,Durham, Robin,Tam, William
experimental part, p. 2138 - 2146 (2010/08/13)
A simple, straightforward, and scalable procedure for the preparation of 2-bromofuran using N-bromosuccinimide (NBS) in dimethylformamide (DMF) is reported. The described preparation is conducted on a 20 to 50g scale and does not require extractive workup procedures or chromatographic purifications. To illustrate the synthetic applications of 2-bromofuran, palladium-catalyzed Suzuki coupling reactions of the prepared 2-bromofuran with various aryl boronic acids were investigated, and moderate to good yields of 2-arylfurans were obtained. Copyright Taylor & Francis Group, LLC.
