Article
Chemistry, Inorganic & Nuclear
Jingjing Zhai, Fen You, Suting Xu, Ao Zhu, Xiaohui Kang, Yat-Ming So, Xiaochao Shi
Summary: A simple and efficient synthetic pathway was developed to prepare a new iminodibenzyl-based PNP pincer proligand, leading to the successful synthesis of a series of iminodibenzyl-PNP rare-earth-metal complexes. Among them, a yttrium complex exhibited high selectivity in the polymerization of 1,3-dienes.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Wei Sun, Meng-Yang Hu, Zhan-Sheng Lu, Ming-Yao Huang, Xin-Yu Zhang, Shou-Fei Zhu
Summary: This article reports a method for stereoselective transformation using an iron catalyst to synthesize Z-allylsilanes with high regioselectivity and exclusive stereoselectivity from E/Z mixtures. The mechanism of this reaction differs from previously reported mechanisms.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Jixing Wang, Suting Xu, Xiang Hu, Yanchen Huo, Xiaochao Shi
Summary: Rare-earth metal complexes bearing pyridyl-functionalized amidinate ligands were synthesized and shown to exhibit high catalytic activities and trans-1,4 regularity for the living polymerization of isoprene and myrcene. The scandium complexes showed the highest activity and produced polymers with the highest trans-1,4 regularity. Additionally, a binary system of 3-Sc/[PhMe2NH][B(C6F5)4] was capable of promoting the block copolymerization of isoprene and epsilon-caprolactone, resulting in copolymers with specific structures.
Article
Chemistry, Multidisciplinary
Ke Chen, Hongdan Zhu, Shuang Liu, Jiahui Bai, Yinlong Guo, Kuiling Ding, Qian Peng, Xiaoming Wang
Summary: This study demonstrates the use of binuclear metal complexes as catalysts to switch the selectivity of 1,3-dienes from 4,3-regioselectivity to 1,4-hydroarylation with Z-stereoselectivity. The findings highlight the potential of binuclear catalysis in achieving new isomers that were previously inaccessible.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Daniele Fiorito, Malaury Simon, Christophe M. Thomas, Clement Mazet
Summary: A [Ni/Mg]-catalyzed orthogonal tandem polymerization has been developed, starting from enol phosphates and leading to 1,4-cis-polydienes with selectivities up to 99%. By simple structural modifications of the monomeric unit, elastomeric or crystalline materials can be obtained. This tandem approach provides a straightforward and efficient way to enforce diversity and selectivity in diene polymerization while retaining a fair degree of control.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Polymer Science
Jian-Ming Huang, Chang-Guang Yao, Shi-Hui Li, Dong-Mei Cui
Summary: The polymerization of 2-(4-halophenyl)-1,3-butadiene and their copolymerization with isoprene using a yttrium catalyst have been studied. The catalyst showed high selectivity for the polymerization of 2-XPB and the insertion ratios of 2-XPB can be tuned. Additionally, quantitative hydrogenation of cis-1,4-poly(2-XPB) resulted in perfect alternating ethylene-halostyrene copolymers.
CHINESE JOURNAL OF POLYMER SCIENCE
(2021)
Article
Chemistry, Organic
Zhi-Lin Liu, Zhi-Peng Ye, Yi-Xuan Chen, Yu Zheng, Zhen-Zhen Xie, Jian-Ping Guan, Jun-An Xiao, Kai Chen, Hao-Yue Xiang, Hua Yang
Summary: We describe a highly modular 1,4-difunctionalization of 1,3-dienes with bromodifluoroacetamides and sulfinates/amines through a photoinduced palladium-catalyzed radical relay process. This protocol offers a facile and general route to access a variety of value-added CF2-incorporated alkenes in moderate to good yields. The versatility and flexibility of this approach have been well demonstrated by readily accessible starting materials, synthetic convenience, and wide functional group compatibility.
Article
Chemistry, Organic
Ming-Hang Bi, Ying Cheng, Wen-Jing Xiao, Jia-Rong Chen
Summary: This study describes a selective three-component 1,4-difluoroalkylesterification enabled by dual photoredox and copper catalysis. The protocol utilizes commercially available CF2-reagents as radical precursors and carboxylic acids as oxygen-based nucleophiles, allowing access to difluoroalkylated allylic esters. Furthermore, this protocol can also be extended to intramolecular two-component 1,4-difluoroalkylesterification for the synthesis of 3-substituted benzobutyrolactones. Preliminary mechanistic studies provide evidence for a radical process.
Article
Chemistry, Organic
Yusuke Tomita, Naoto Haraguchi, Sayori Kiyota, Nobuyuki Komine, Masafumi Hirano
Summary: A traditional cobalt catalyst system has been found to exhibit previously undiscovered reactivity. Depending on the choice of tertiary phosphines and substrates, this catalytic system can catalyze diverse cycloadditions, yielding various cyclic compounds. The bite angles of the ligands used significantly contribute to the catalytic diversity.
Article
Chemistry, Organic
Chang-Sheng Kuai, Bing-Hong Teng, Da-Lie An, Yingying Zhao, Xiao-Feng Wu
Summary: A palladium-catalyzed carbonylation of 2-trifluoromethyl-1,3-enynes has been developed, providing access to multisubstituted conjugated dienes. This method exhibits excellent regio- and exclusive (E)-stereoselectivity and demonstrates broad substrate scope with both amines and alcohols as reaction partners, showing promising functional group tolerance.
Article
Chemistry, Physical
Ruoshui Xu, Laurence N. Rohde, Steven T. Diver
Summary: A regioselective Cu-catalyzed formal hydroboration of 1,3-disubstituted-1,3-dienes is reported. Highly substituted 1,3-dienes produced through catalytic ene-yne metathesis serve as substrates for the regioselective hydroboration with variable substituents. The reaction can be achieved with both achiral and enantioselective conditions.
Article
Chemistry, Multidisciplinary
Zeming Huang, Shaowu Wang, Xiancui Zhu, Yun Wei, Qingbing Yuan, Shuangliu Zhou, Xiaolong Mu, Hua Wang
Summary: In this study, a novel indolyl-based NCN pincer ligand precursor HL was designed and synthesized successfully, leading to various rare-earth metal chlorides and mixed complexes. The complexes were fully characterized and their structures determined, with further characterization using NMR spectroscopy for specific complexes. The research demonstrated that factors such as central metal ions and borates have influences on the catalytic activity and regio- and stereoselectivity for the polymerization of isoprene.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Fen You, Wenyu Shi, Xuyang Yan, Xiaoyu Wang, Xiaochao Shi
Summary: The reliance on fossil resources and the accumulation of polymeric materials in the environment pose significant challenges to sustainable society. Utilizing renewable monomers for polymeric materials has gained attention, and terpenes are a commonly used bio-based monomer. This review focuses on the rare-earth metal catalyzed polymerization of bio-based conjugated dienes from terpene-derived compounds, and discusses the future directions for modifying these bio-based conjugated dienes.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Applied
Ze-Jian Xue, Meng-Yao Li, Bin-Bin Zhu, Zhi-Tao He, Chen-Guo Feng, Guo-Qiang Lin
Summary: The palladium-catalyzed cross-coupling of ortho-vinyl aromatic bromides and olefins using a controllable 1,4-palladium migration/Heck cascade protocol is a mild, efficient, and highly stereoselective method for the synthesis of trisubstituted 1,3-dienes, especially triaryl-substituted ones.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Polymer Science
Giovanni Ricci, Guido Pampaloni, Anna Sommazzi, Francesco Masi
Summary: Research activity in the stereospecific polymerization of conjugated dienes has recently focused on the use of organometallic catalysts with well-defined structures and various types of ligands, which can strongly influence polymerization regio- and stereoselectivity, molecular weights, and living characteristics of the catalysts. Recent results in this field are highlighted in this Perspective, along with discussions on possible future developments.
Article
Biochemical Research Methods
Hideaki Ishii, Mariko Shibuya, Yat-Ming So, Jenny K. Y. Wong, Emmie N. M. Ho, Kanichi Kusano, Yu Sone, Takahiro Kamiya, Ai Wakuno, Hideki Ito, Kenji Miyata, Masayuki Yamada, Gary Ngai-Wa Leung
Summary: A long-term longitudinal analysis of IOX4 in horse hair showed that the substance could be detected in horse hair up to 6 months postadministration, with no metabolites detected. The study also found individual variation in the distribution of IOX4 in the hair shaft over 6 months, with a significant diffusion of IOX4 observed in the postadministration hair samples.
DRUG TESTING AND ANALYSIS
(2022)
Article
Biochemical Research Methods
Hideaki Ishii, Mariko Shibuya, Yat-Ming So, Jenny K. Y. Wong, Emmie N. M. Ho, Kanichi Kusano, Yu Sone, Takahiro Kamiya, Ai Wakuno, Hideki Ito, Kenji Miyata, Masayuki Yamada, Gary Ngai-Wa Leung
Summary: IOX4, a HIF-PHD inhibitor, has hematopoietic effects for the treatment of anemia. Metabolic study in horses showed various metabolites of IOX4 in plasma and urine, as well as their corresponding detection times.
DRUG TESTING AND ANALYSIS
(2022)
Article
Chemistry, Inorganic & Nuclear
Fen You, Suting Xu, Jixing Wang, Jingjing Zhai, Fei Wang, Li Pan, Yat-Ming So, Xiaochao Shi
Summary: A simple method for accessing new derivatizable bulky-demanding OHF ligands has been developed, leading to the synthesis of a series of half-sandwich rare-earth metal complexes bearing the OHF ancillary ligands, which exhibit high catalytic activity for styrene (co)polymerization.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Jingjing Zhai, Fen You, Suting Xu, Ao Zhu, Xiaohui Kang, Yat-Ming So, Xiaochao Shi
Summary: A simple and efficient synthetic pathway was developed to prepare a new iminodibenzyl-based PNP pincer proligand, leading to the successful synthesis of a series of iminodibenzyl-PNP rare-earth-metal complexes. Among them, a yttrium complex exhibited high selectivity in the polymerization of 1,3-dienes.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Jixing Wang, Suting Xu, Xiang Hu, Yanchen Huo, Xiaochao Shi
Summary: Rare-earth metal complexes bearing pyridyl-functionalized amidinate ligands were synthesized and shown to exhibit high catalytic activities and trans-1,4 regularity for the living polymerization of isoprene and myrcene. The scandium complexes showed the highest activity and produced polymers with the highest trans-1,4 regularity. Additionally, a binary system of 3-Sc/[PhMe2NH][B(C6F5)4] was capable of promoting the block copolymerization of isoprene and epsilon-caprolactone, resulting in copolymers with specific structures.
Article
Polymer Science
Fen You, Xiaohui Kang, Masayoshi Nishiura, Jingjing Zhai, Suting Xu, Jixing Wang, Xiaochao Shi, Zhaomin Hou
Summary: This study reports the living and highly 3,4-isoselective polymerization of biobased monomer beta-farnesene using a phosphine-functionalized fluorenyl-ligated yttrium catalytic system. The coordination of the phosphine group plays a pivotal role in the regio- and stereoselectivity of the polymerization. Block copolymers with specific properties were successfully prepared. This research is important for reducing petrochemical dependency.
Review
Chemistry, Multidisciplinary
Fen You, Wenyu Shi, Xuyang Yan, Xiaoyu Wang, Xiaochao Shi
Summary: The reliance on fossil resources and the accumulation of polymeric materials in the environment pose significant challenges to sustainable society. Utilizing renewable monomers for polymeric materials has gained attention, and terpenes are a commonly used bio-based monomer. This review focuses on the rare-earth metal catalyzed polymerization of bio-based conjugated dienes from terpene-derived compounds, and discusses the future directions for modifying these bio-based conjugated dienes.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Polymer Science
Wenhui Ren, Fen You, Jingjing Zhai, Xiaohui Kang, Yat-Ming So, Xiaochao Shi
Summary: This study presents a single rare-earth metal catalyst that can promote the polymerization of isoprene and butadiene with unmatched stereoselectivity, resulting in polymers with different cis or trans structures. Moreover, the catalyst allows for the precise control of diblock and multiblock copolymers with differently stereoselective adjacent blocks. The mechanical properties of the produced block copolymers can be tailored by controlling the sequence length.
Article
Chemistry, Inorganic & Nuclear
Hui Liu, Fen You, Xiang Hu, Yanchen Huo, Xiaochao Shi
Summary: A family of rare-earth metal complexes with diverse chiral substituents were synthesized and exhibited high catalytic activity and heteroselectivity in ring-opening polymerization. The yttrium complexes showed higher activity and heteroselectivity, while the chiral substituents had slight influence on the reaction.
Article
Biochemical Research Methods
Yat-Ming So, Jenny K. Y. Wong, April S. Y. Wong, Alice T. L. Tse, Terence S. M. Wan, Emmie N. M. Ho
Summary: The peptide EMP1-linear, found in white crystalline powder allegedly used for doping racehorses, can cyclize into EMP1, a well-known erythropoiesis stimulating agent. An in vitro metabolic study using horse liver S9 fraction revealed the presence of four metabolites of EMP1-linear, while an intravenous administration study in thoroughbred geldings showed the detection of EMP1 and the metabolites in postadministration plasma and urine samples. Among the metabolites, M3 had the longest detection time of up to 4 hours in plasma and 27 hours in urine, making it a potential target for controlling the misuse of EMP1-linear in equine sports.
DRUG TESTING AND ANALYSIS
(2023)
Article
Chemistry, Inorganic & Nuclear
Suting Xu, Yanchen Huo, Xiang Hu, Fei Wang, Li Pan, Xiaochao Shi
Summary: In this study, rare-earth metal complexes bearing tetrahydrofluorenyl ligands were synthesized and characterized. These complexes showed excellent catalytic activity for the polymerization of styrene and butadiene, resulting in diblock copolymers with highly syndiotactic polystyrene block and a 1,4-specific PBD block. The study also revealed the significant difference in reactivity ratios between butadiene and styrene, supporting the block structure of the copolymers. Morphology and mechanical properties of the selected diblock copolymer were investigated.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Hoang-Long Pham, Thayalan Rajeshkumar, Lily Ueh-hsi Wang, Yat Hei Ng, Kai-Hong Wong, Yat-Ming So, Herman H. Y. Sung, Rolf Lortz, Ian D. Williams, Laurent Maron, Wa-Hung Leung
Summary: The steric and electronic effects on the stability and reactivity of cerium(IV) aryloxide complexes have been studied using the Kläui tripodal ligand [Co(eta(5)-C5H5){P(O)(OEt)(2)}(3)](-) (L-OEt(-)) as a support. Ce(IV) aryloxide complexes were synthesized using a Ce(IV) oxo species prepared in situ. The study found that the substituents of the aryloxide ligands did not significantly affect the Ce-O bond lengths and Ce-O-C angles.
Article
Chemistry, Inorganic & Nuclear
Fen You, Jixing Wang, Hui Liu, Xiaohui Kang, Xiaochao Shi
Summary: A series of rare-earth metal bis(alkyl) complexes were synthesized through protonolysis reactions of tris(aminobenzyl) complexes with phosphine-functionalized amidinated ligands. These complexes showed high catalytic activity for the polymerization of 1,3-conjugated dienes, resulting in highly 3,4-regular polymers with high molecular weight and narrow molecular weight distribution. The coordination of the diphenylphosphine group to the central metal was observed, which may serve as the true active species in the 3,4-selective polymerization of 1,3-conjugated dienes according to 31P NMR spectra and DFT calculation results.
DALTON TRANSACTIONS
(2023)
Article
Polymer Science
Hui Liu, Fen You, Wenyu Shi, Xiang Hu, Yat-Ming So, Xiaochao Shi
Summary: In this study, we developed a series of novel terpene-derived conjugated dienes and successfully achieved their highly selective polymerization, resulting in high-molecular-weight polymers with high glass transition temperatures and excellent thermal stability.