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Sun B.,Northeast Normal University | Sun B.,Changchun University of Chinese Medicine | Ma Q.,Changchun University of Chinese Medicine | Wang Y.,Jilin Normal University | And 4 more authors.
European Journal of Organic Chemistry | Year: 2014

An environmentally friendly route to fully substituted 4,5-dihydropyrroles was developed through the iron-catalyzed [4C+1N] cyclization of 4-acetylenic ketones with primary amines in 1,5-pentanediol. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Fang Z.,Northeast Normal University | Liao P.,Northeast Normal University | Yang Z.,Northeast Normal University | Wang Y.,Jilin Normal University | And 4 more authors.
European Journal of Organic Chemistry | Year: 2014

Differently substituted 4-(1,3-dithiolan-2-ylidene)but-1-ynes were conveniently converted into the corresponding thiophenes and dihydrothiophenes in good to high yields under mild conditions. 1,3-Dithiolan-2-ylidene acted as a masked thiolate anion and underwent tandem fragmentation and 5-exo-dig annulation with an alkyne moiety to form the five-membered sulfur heterocycles. An efficient and atom-economic approach for the preparation of densely functionalized 2,3-dihydrothiophenes and thiophenes is reported. For the first time, the strategic use of 1,3-dithiolan-2-ylidene as a masked thiolate anion is used in a tandem fragmentation and 5-exo-dig annulation with an alkyne moiety to form five-membered sulfur heterocycles. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Wang Z.,CAS Changchun Institute of Applied Chemistry | Bi X.,Northeast Normal University | Bi X.,State Key Laboratory of Elemento Organic Chemistry | Liao P.,Northeast Normal University | And 3 more authors.
Chemical Communications | Year: 2013

A novel Cu(ii)-catalyzed cyclization of α-diazo-β-oxoamides with amines has been developed, constituting a straightforward method to construct pyrrol-3(2H)-one rings. The intramolecular hydrogen bonding effect in α-diazo-β-oxoamides plays an essential role in this reaction. A plausible reaction mechanism involving divergent generation and subsequent [2 + 3] cyclization of ketene and α-diazoimine intermediates was proposed. © 2012 The Royal Society of Chemistry. Source


Xu C.,State Key Laboratory of Elemento Organic Chemistry | Chen Y.,Nankai University | Zhang H.-Y.,Nankai University | Liu Y.,Nankai University
Journal of Photochemistry and Photobiology A: Chemistry | Year: 2015

A crown ether-based supramolecular gel with a three-dimensional network structure was successfully constructed via a hierarchical induced assembly strategy and characterized by UV/vis NMR, viscometry and DLS. Therein, the coordination linkage of bis(terpyridyl)dibenzo-24-crown-8 1 with Zn2+ produces the 1/Zn2+ supramolecular polymer as the primary assembly. Then, the anthryl-dibenzylammonium guest 2 was grafted to the 1/Zn2+ supramolecular polymer via the non-covalent association of dibenzylammonium moieties on guests with the dibenzo-24-crown-8 rings on supramolecular polymer. Furthermore, the supramolecular polymer with anthryl grafts underwent a photo-induced secondary assembly to produce the supramolecular gel, which could be reversibly disassembled by a thermo-induced dissociation of anthracene dimers. These photo/thermo-induced hierarchical assembly/disassembly behaviors will provide a potential way to construct degradable hierarchical supramolecular assemblies employing environment-friendly external stimuli, such as light and heat, as controlling method. © 2015 Elsevier B.V. Source


Shen G.-B.,State Key Laboratory of Elemento Organic Chemistry | Xia K.,State Key Laboratory of Elemento Organic Chemistry | Li X.-T.,State Key Laboratory of Elemento Organic Chemistry | Li J.-L.,State Key Laboratory of Elemento Organic Chemistry | And 4 more authors.
Journal of Physical Chemistry A | Year: 2016

In this work, kinetic isotope effect (KIEself) values of 68 hydride self-exchange reactions, XH(D) + X+ → X+ + XH(D), in acetonitrile at 298 K were determined using a new experimental method. KIE values of 4556 hydride cross transfer reactions, XH(D) + Y+ → X+ + YH(D), in acetonitrile were estimated from the 68 determined KIEself values of hydride self-exchange reactions using a new KIE relation formula derived from Zhu's kinetic equation and the reliability of the estimations was verified using different experimental methods. A new KIE kinetic model to explain and predict KIE values was developed according to Zhu's kinetic model using two different Morse free energy curves instead of one Morse free energy curve in the traditional KIE theories to describe the free energy changes of X-H bond and X-D bond dissociation in chemical reactions. The most significant contribution of this paper to KIE theory is to build a new KIE kinetic model, which can be used to not only uniformly explain the various (normal, enormous and inverse) KIE values but also safely prodict KIE values of various chemical reactions. © 2016 American Chemical Society. Source

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