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Recent advances on iron-catalyzed coupling reactions involving organolithium reagents

Chinese Chemical Letters 2019年第8期30卷 1463-1467页

作者： Zhuliang Zhong Xiao-Shui Peng Henry N.C.Wong Department of Chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong Kong

Owing to their inexpensive and environmentally friendly properties,iron-based catalysts have been actively investigated for new organic *** this account,we summarized our recent results on iron-catalyzed cross-coupling reactions and homo-coupling *** iron-based catalysts,we constructed diverse carbon-carbon bonds,i.e.,C(sp^2)-C(sp^3),C(sp^3)-C(sp^3),C(sp^3)-C(sp^2)and C(sp^2)-C(sp^2)*** order to demonstrate the usefulness of our iron protocol,we also carried out these reactions on gram-scale reactions,leading to good yields.

关键词： Iron-catalyzed Cross-coupling Homo-coupling organolithium Gram-scale

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A Novel Efficient Ligand in Anionic Polymerization at Elevated Temperature

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Chinese Journal of Chemistry 2014年第11期32卷 1128-1134页

作者： Bo Chen Jiming Wang Minze Shu Bin Zou Yong Guan Anna Zheng Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

This work confirmed a novel ligand in the anionic polymerization,lithium phenoxide,which helped to improve the controllability of the *** stability of n-BuLi against THF at 0℃ was effectively improved by adding lithium *** than 60%n-BuLi in THF was alive with the presence of lithium phenoxide after stirring at 0℃ for 20 min,compared to 2%under same conditions but without lithium *** propagation of polymerization of styrene(St)and methyl methacrylate(MMA)were retarded after adding lithium *** by adding more than 10 fold lithium phenoxide,completed conversion was achieved in the polymerization of MMA in THF at 0℃.The lithium phenoxide showed both promoting and inhibiting effects in the polymerization of isoprene(Ip):it promoted the formation of 3,4-structure,while mitigated the formation of 1,2-and 1,*** general,the polymerization rate of Ip was promoted by lithium phenoxide.

关键词： ligand anionic polymerization kinetics organolithium

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A New View of the Initiation and Propagation in Anionic Polymerization

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Chinese Journal of Chemistry 2013年第3期31卷 393-400页

作者： Anna Zheng Bo Chen Dihang Hu Yong Guan Dafu Wei Shuzhao Li Dandan Ji Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials ofMinistry of Education School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 China

This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene with the help of a self designed microflow device and characterized by GPC and in situ ^7Li NMR. It was found that n-BuLl tended to form the hexameric-aggregated structure and even to form the huge aggregated structure based on the former. These aggregations of initiators could directly initiate the anionic polymerization and form the su-pramolecule aggregations. The supramolecule aggregations inevitably blocked the diffusion of the monomers to the ion-pairs and resulted in a stationary-conversion platform. Then the aggregators were dissociated completely into equal binary-aggregated species, and the polymerization continued again rapidly before the termination. Tetrahy-drofuran （THF） acted as the electron donator, which could push the electron cloud to Li cation and make the aggre- gated ring of the active species rather loosened and facilitated the monomer to insert in. Therefore, a little THF can greatly promote the anionic polymerization. However, further addition of THF might block the channel between the ion-pairs and decrease the propagation rate. It was also found that the aggregated structure of the active species during the anionic polymerization only depends on the initiator aggregations which were formed before the polym-erization.

关键词： anionic polymerization initiation mechanism in situ 7^Li NMR organolithium supramolecular aggre-gator

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Synthesis and Characterization of Three Pentacene Derivatives

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Transactions of Tianjin University 2018年第5期24卷 453-460页

作者： Hongmei Qu Haijiao Shen Junqiu Li Yican Men Xu Chen Zepeng Chong Key Laboratory of Systems Bioengineering (Ministry of Education) Tianjin University Tianjin Kingsrial S&T Co. Ltd

The addition of substituents at the 6,13-position improved the solubility and stability of pentacene, making it possible to use the derivatives in spin coating of organic field-effect transistors(OFETs). Three pentacene derivatives, 6,13-bis(m-tolyl)pentacene(MP), 6,13-bis(4-butylphenyl)pentacene(BP), and 6,13-bis((4-butylphenyl)ethynyl)pentacene(BPEP) were synthesized, and their properties were investigated. 6,13-Pentacenequinone and organolithium were used in the preparation of 6,13-dihydropentacene at 0 ℃, and pentacene derivatives were synthesized with SnCl_2/HCl as reducing agent, to reduce 6,13-dihydropentacene at room temperature. The structure of the derivatives was characterized using NMR. The thermal stability, photochemical properties, and electronic structure of the three compounds were investigated using TGA, cyclic voltammetry, and UV–Vis. BPEP was also characterized using X-ray diffraction and atom force microscopy. BPEP was used to fabricate an OFET device using spin coating. The device showed a mobility of 0.07 cm^2 V s^(-1) at V_(th) =-10 V and I_(ON)/I _(OFF) = 10~2.

关键词： organolithium Reduction reaction Mobility OFET Spin coating

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