Article
Chemistry, Multidisciplinary
Changli He, Xiaoxue Tang, Xin He, Yuqiao Zhou, Xiaohua Liu, Xiaoming Feng
Summary: Reversal of regioselectivity in the catalytic asymmetric conjugate additions of 3-substituted oxindoles to beta-nitroenones or beta-nitroacrylates was achieved with chiral scandium catalysts. Functionalized 3,3-disubstituted oxindoles, including terminal and internal vinyl groups, were constructed in excellent yields and ee values.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Organic
Ya-Ping Wang, Xing-Ping Zhang, Ming-Sheng Xie, Hai-Ming Guo
Summary: In this study, highly enantioselective propargyl Claisen rearrangement of O-propargyl beta-ketoesters was achieved using a chiral cobalt complex as the catalyst under mild reaction conditions. A diverse range of chiral allenyl-substituted all-carbon quaternary beta-ketoesters were obtained in good yields and high enantioselectivities.
Article
Chemistry, Physical
Mingjun Lv, Xiaoxun Li
Summary: This study reports a nickel-catalyzed asymmetric nitration reaction that successfully synthesized chiral oxindoles with a tertiary nitro group in good yields and high enantioselectivities. The resulting products can be used for the synthesis of chiral 3-amino oxindoles and demonstrate the synthetic potential for analogues of the antimalarial agent Cipargamin.
Article
Chemistry, Physical
Ningning Zhang, Zhiyong Sun, Changzhu Wu
Summary: The polymeric approach of combining proteins with organocatalytic polymers to generate artificial enzymes expands the applications of asymmetric organocatalysis and provides new avenues for combining proteins/enzymes with well-designed organocatalytic polymers for useful synthetic reactions.
Article
Chemistry, Physical
Liangliang Zhang, Martin Oestreich
Summary: The passage describes a reaction sequence involving enantioselective copper-catalyzed conjugate silylation and diastereotopic group-selective aldol cyclization. The intramolecular aldol reaction's diastereoselectivity depends on the silicon nucleophile used, and the more basic zinc reagent enables thermodynamically driven cis-to-trans isomerization. A wide range of electron-withdrawing groups, including electron-deficient heterocycles, are compatible with the different procedures developed.
Article
Chemistry, Multidisciplinary
Tianhong Wang, Youbin Peng, Guanlin Li, Yicong Luo, Yong Ye, Xiaohong Huo, Wanbin Zhang
Summary: The highly regio-, enantio-, and diastereoselective allylic alkylation of 3-alkyl oxindoles through synergistic iridium and copper catalysis provides a series of 3,3-disubstituted oxindole derivatives containing adjacent quaternary and tertiary stereogenic centers in excellent yields, enantiomeric excess, and diastereomeric ratio. The method demonstrates exclusive branched selectivity, excellent enantio- and diastereoselectivities, and good functional compatibility, with the chiral copper catalyst being crucial for achieving high reactivities and diastereoselectivities under mild reaction conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Junwen Wang, Jun Li, Yan Wang, Sisi He, Hengzhi You, Fen -Er Chen
Summary: In this study, a polymer-supported chiral heterogeneous copper catalyst was reported, which demonstrated high reactivity and enantioselectivity in asymmetric conjugate addition reactions.
Article
Chemistry, Multidisciplinary
Jun-Jie Tian, Rui-Rui Li, Gui-Xiu Tian, Xiao-Chen Wang
Summary: Here, we describe a new method for enantioselective C-H allylation of pyridines at C3 using a tandem borane and palladium catalysis. This method involves borane-catalyzed pyridine hydroboration, palladium-catalyzed enantioselective allylation of the resulting dihydropyridines with allylic esters, and air oxidation to afford the products. This method allows for the introduction of an allylic group at C3 with excellent regio- and enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Sourav Dutta, Arka Porey, Joyram Guin
Summary: Here, we present an efficient strategy for the enantioselective synthesis of oxindoles with a C3-quaternary stereocenter using N-heterocyclic carbene (NHC) catalyzed desymmetrization of diols. The process involves the catalytic asymmetric transfer acylation of primary alcohols using readily available aldehydes. This reaction provides easy access to diverse C3-quaternary oxindoles with excellent enantioselectivity. The synthetic potential of the process is demonstrated through the preparation of key intermediates for (-)-esermethole and (-)-physostigmine.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Vibha V. Kanale, Christopher Uyeda
Summary: Cobalt catalysts facilitate highly enantioselective ring-opening reactions of 2,5-dihydrofurans using vinylidenes. The resulting products are acyclic organozinc compounds, capable of further functionalization with an electrophile. The proposed mechanism involves the formation of a cobalt vinylidene species that adds to the alkene via a [2+2]-cycloaddition pathway, followed by ring-opening through outer-sphere & beta;-O elimination assisted by a ZnX2 Lewis acid. DFT models explain the observed stereochemical outcome by suppressing competing inner-sphere syn & beta;-H and & beta;-O elimination pathways due to the geometric constraints of the metallacycle intermediate. Cobalt catalysts also promote enantioselective ring-opening reactions of unstrained heterocycles via reductive addition of 1,1-dichloroalkenes. The resulting products are acyclic homoallylic alcohols with a vinylzinc motif, which can be further modified with an electrophile. Mechanistic studies suggest that the ring-opening occurs through outer-sphere & beta;-O elimination facilitated by a Zn(II) Lewis acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Wenkun Yang, Pei Dong, Jian Xu, Jian Yang, Xiaohua Liu, Xiaoming Feng
Summary: In this study, a chiral N,N'-dioxide-nickel(II) complex-catalyzed asymmetric amination method was developed for the synthesis of alkyl or aryl 3-amino-indolinones with quaternary stereocenters in high yields with excellent ee values. The proposed method offers a convenient route to optically active intermediates of 3-amino-2-oxindole-based bioactive compounds, and a possible transition-state model was proposed to elucidate the origin of the chirality based on the X-ray crystal structure of the catalyst and the adduct.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Yoshimi Kato, Luqing Lin, Masahiro Kojima, Tatsuhiko Yoshino, Shigeki Matsunaga
Summary: By introducing pseudo-C2 symmetric tunable chiral carboxylic acids, the study achieved enantioselective C(sp(3))-H amidation reactions of substrates such as 2-alkylpyridines, improving the chiral selectivity towards the substrates.
Review
Chemistry, Applied
Sara Meninno, Francesca Franco, Maurizio Benaglia, Alessandra Lattanzi
Summary: Pyrazoleamides have gained attention as reactive and practical surrogates in asymmetric catalysis, particularly in a variety of metal- and organocatalytic transformations. Their relevance has extended to photoredox catalysis and challenging stereoselective bond-forming reactions in recent years.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Physical
Zhenhua Xie, Haoyue Guo, Erwei Huang, Zhongtian Mao, Xiaobo Chen, Ping Liu, Jingguang G. Chen
Summary: The study identified the desired ethylene/CO/H-2 ratios by analyzing different combinations of main and side reactions of CO2 and ethane, and found that the PtSn3/gamma-Al2O3 catalyst has promising potential for the tandem hydroformylation reaction. Experimental and theoretical studies revealed the importance of Pt cluster/SnOx interfacial structures in the conversion of ethane into C3 oxygenates.
Article
Chemistry, Multidisciplinary
Won Jun Jang, Jeongkyu Woo, Jaesook Yun
Summary: The study reported a method to synthesize enantioenriched alkylboron compounds through conjugate addition, which are influenced by two contiguous carbon stereogenic centers, with high yield and enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Materials Science, Multidisciplinary
Shakeel Ahmed, Xiantao Jiang, Cong Wang, Um E. Kalsom, Bing Wang, Jahanzeb Khan, Yasin Muhammad, Yanmin Duan, Haiyong Zhu, Xiangzhong Ren, Han Zhang
Summary: This paper provides a comprehensive overview and discussion on recent experimental advancements in the NLO response and its applications in various 2D materials.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Plant Sciences
Zareen Sarfraz, Muhammad Shahid Iqbal, Xiaoli Geng, Muhammad Sajid Iqbal, Mian Faisal Nazir, Haris Ahmed, Shoupu He, Yinhua Jia, Zhaoe Pan, Gaofei Sun, Saghir Ahmad, Qinglian Wang, Hongde Qin, Jinhai Liu, Hui Liu, Jun Yang, Zhiying Ma, Dongyong Xu, Jinlong Yang, Jinbiao Zhang, Zhikun Li, Zhongmin Cai, Xuelin Zhang, Xin Zhang, Aifen Huang, Xianda Yi, Guanyin Zhou, Lin Li, Haiyong Zhu, Baoyin Pang, Liru Wang, Junling Sun, Xiongming Du
Summary: Plant breeding has long utilized heterosis to increase agricultural productivity, but the underlying genes and processes fostering heterosis are not well understood. A study on cotton hybrids revealed key SNPs/QTNs and hQTNs related to agronomic and fiber quality traits, including 275 candidate genes in their vicinity. The identification of novel genes linked to heterosis mechanisms in cotton could be important for biologists and cotton breeders looking to improve fiber and yield traits.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
Zhihong Li, Haiyong Zhu
Summary: By using a tilted fiber grating supported by nanometric-scale gold and TiO2 films, this study investigates the excitation mechanism and sensing performance of fiber-optic surface waveguide modes. It is found that P-polarized surface waveguide modes are more sensitive compared to S-polarized modes, opening up new pathways for single molecular detection.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Zhihong Li, Xianxin Yang, Haiyong Zhu, Francesco Chiavaioli
Summary: The deposition of high refractive index nanocoatings is a powerful technique for enhancing light-matter interaction in fiber optic devices, although it can also lead to reduced sensitivity in certain cases. This study on nanocoated tilted fiber Bragg gratings reveals that nanocoatings can enhance polarization-dependent sensing performance through tuning polarized dispersion properties. P-polarization shows higher sensitivity to bulk refractive index changes, while S-polarization is more sensitive to surface changes, providing options for different refractometric sensing applications.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Yahong Li, Xiaohong Huang, Wenjie Mao, Jing Xu, Yanmin Duan, Haiyong Zhu
Summary: A compact 589 nm yellow source was achieved by intracavity frequency doubling of a c-cut YVO4/Nd:YVO4/YVO4 Raman laser. Passively Q-switched operation was performed using a Cr4+:YAG/YAG composite, and a double-end composited Nd:YVO4 crystal was designed to minimize thermal effects. Noncritical phase-matching (NCPM) LBO crystal and critical phase-matching (CPM) BBO crystal were used as frequency doubling crystals for comparison.
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
(2023)
Article
Optics
Chenghao Liu, Mariusz Klimczak, Ryszard Buczynski, Jian Kong, Lian Cheng, Andrey Komarov, Xiahui Tang, Ming Tang, Haiyong Zhu, Luming Zhao
Summary: In this study, pulse shrinkage of dissipative soliton resonance (DSR) pulses in a fiber laser is investigated. It is found that when the gain continues to increase, the DSR pulses undergo shrinkage, contrary to the expected pulse broadening. Additionally, pulse shrinkage and period doubling can be observed by changing the initial settings.
OPTICS COMMUNICATIONS
(2022)
Article
Optics
Sheng Chen, Quanxin Na, Changwen Xu, Tenggui Xu, Quanming Li, Hongwen Xuan, Haiyong Zhu, Yan Zhang, Dianyuan Fan
Summary: A Nd:YAG single-crystal fiber amplifier, pumped by a laser diode, was investigated for the amplification of continuous-wave single-frequency laser. By using a two-stage amplification configuration, an output power of 60.4 W was achieved, which is the highest power ever achieved with a single-crystal fiber scheme for continuous-wave single-frequency laser.
Article
Materials Science, Multidisciplinary
Zhigang Li, Dou Zhang, Lei Zhang, Chao Ruan, Qin Zhou, Yongfu Lian
Summary: In this study, nickel encapsulated carbon onions (CNOs) were fabricated and found to exhibit better electromagnetic wave absorption (EMWA) performance, indicating that the core-shell interface contributes more to EMWA.
JOURNAL OF MOLECULAR AND ENGINEERING MATERIALS
(2022)
Article
Oncology
Tiezhi Li, Helin Zhang, Zhichao Wang, Shaolin Gao, Xu Zhang, Haiyong Zhu, Na Wang, Honglin Li
Summary: This study found that the miR-199a-5p/p62 axis is involved in the regulation of autophagy in cisplatin-resistant small cell lung cancer. Treatment of H446/EP cells with cisplatin increased the levels of LC3II/LC3I, ATG5, p62, and autophagolysosome formation in H446 cells, but not in H446/EP cells. The expression of miR-199a-5p was up-regulated in H446/EP cells and it directly targeted the p62 gene. The expression of miR-199a-5p and p62 were correlated in small cell lung cancer samples.
CANCER CELL INTERNATIONAL
(2022)
Article
Optics
Yanmin Duan, Yuming Zhou, Haiyong Zhu, Zhihong Li, Xinxin Jin, Dingyuan Tang
Summary: Selective frequency mixing in a cascaded Nd:YVO4 self-Raman laser was studied for wavelength-switchable visible light output. Phase-matching with temperature tuning of LBO crystals was analyzed, and it was found that a critical phase-matched LBO crystal can generate five discrete visible wavelengths without sub-zero cooling. The laser showed high average output power across three visible wavelengths, indicating potential for practical multi-wavelength tunable laser sources.
JOURNAL OF LUMINESCENCE
(2022)
Review
Physics, Multidisciplinary
Jie Liu, Yanmin Duan, Zhihong Li, Ge Zhang, Haiyong Zhu
Summary: This study reviews nonlinear frequency conversions of vortex lasers and discusses the characteristics of different frequency conversions. It is hoped that this review can serve as a reference for future research and suggests expanding the wavelength range.
FRONTIERS IN PHYSICS
(2022)
Article
Optics
Yanmin Duan, Jing Xu, Yahong Li, Zhihong Li, Xinxin Jin, Haiyong Zhu
Summary: This study reports the design and operation optimization of two self-Raman lasers for emission at 1216 nm and 608 nm. By using double-end diffusion-bonded Nd:YVO4 composite crystal and a non-critically phase matched LBO crystal, efficient operation with specific wavelength emission was achieved.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Zhihong Li, Fei Wang, Xinxin Jin, Yanmin Duan, Haiyong Zhu
Summary: This study comprehensively investigates the integration of metal clad with dielectric waveguide and proposes a versatile approach for analyzing fiber-optic surface waveguide resonances (SWRs) and other types of optical surface waves. The results demonstrate that the introduction of a metal clad enhances the guidance of surface waveguide modes and improves mode coupling with fiber modes. By adjusting the thickness of the film waveguide, strongly polarization-dependent fiber-optic SWRs can be generated.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Crystallography
Jie Liu, Yanmin Duan, Wenjie Mao, Xinxin Jin, Zhihong Li, Haiyong Zhu
Summary: In this study, the generation of a self-Raman vortex laser using acousto-optic modulation was achieved for the first time. Beam cleaning-up and pulse compression effects were observed, along with the successful creation of a Stokes field carrying a unitary topological charge. The vortex laser exhibited high peak power and short pulse width, making it suitable for various applications.
Review
Materials Science, Multidisciplinary
Nasir Mahmood Abbasi, Yao Xiao, Li Zhang, Ling Peng, Yanhong Duo, Lude Wang, Peng Yin, Yanqi Ge, Haiyong Zhu, Bing Zhang, Ni Xie, Yanmin Duan, Bing Wang, Han Zhang
Summary: Due to shortcomings of graphene-based applications in certain electronic devices, researchers have been exploring alternative 2D materials such as MXenes. MXenes have unique properties like hydrophilicity and metallicity, making them a focus of research. However, MXenes also have deficiencies that need to be addressed, such as improving their conductivity.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
