Article
Chemistry, Organic
Sarah E. Luderer, Behrad Masoudi, Aritra Sarkar, Calvin Grant, Arvind Jaganathan, James E. Jackson, Babak Borhan
Summary: Various structural elements of Cinchona alkaloid dimers were studied to establish a structure-enantioselectivity relationship (SER) in three different halocyclization reactions. The sensitivity of SER to linker rigidity and polarity, alkaloid structure, and the presence of alkaloid side groups defining the catalyst pocket varied in the chlorocyclizations. DFT calculations on methoxylated models revealed high barriers to ether rotation, indicating the importance of conformational rigidity in linker-ether connections.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Hao Sun, Pinli Dai, Jie Tian, Qian Xu, Qian Chen, Linlin Li, Xin Meng, Lin Zhang, Chun Li
Summary: A variety of NN ligands derived from cinchona alkaloids with N-H groups were used for the asymmetric hydrogenation of ketones. Substituting the N-H group of the ligands showed that it was essential for asymmetric hydrogenation, as without it the reaction could not proceed. The optimal ligand demonstrated high enantioselectivity (up to 98.8% ee) and good yields for various aromatic and α,β-unsaturated ketones.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Sanjiv O. Tomer, Hemant P. Soni
Summary: In this study, the molecular structure of quinidine was modified and a chiral hemiester catalyst with high enantioselectivity and yield was successfully synthesized.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Physical
Shuai Wei, Jianing Zhang, Shan Li, Xuebing Ma
Summary: A ship-in-a-bottle strategy was developed for the direct and simple immobilization of 9-amino-(9-deoxy)epi-quinine into hollow polystyrene nano-bowls, achieving good catalytic performance in heterogeneous organocatalysis. The immobilized catalyst displayed fast mass transfer and excellent stability and reusability in acetal hydrolysis/asymmetric aldol tandem reactions. Good to excellent catalytic performances were achieved for acetals bearing electron-withdrawing substituents.
Article
Engineering, Mechanical
Yu Wang, Tianqiao Mao, Bo Zhang, Yingjie Xia, Xuefeng Yi
Summary: This study investigates the influence of confining pressure on the macro-meso fatigue damage and instability characteristics of fault bimrock. It is found that strength, deformation, and stiffness of the bimrock increase with increasing confining pressure. A damage evolution pattern shaped like an inverted L and S is revealed and modeled. Post-test CT scanning visualizes the multiple interface cracking behaviors and volumetric change.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Chemistry, Physical
Jie Yang See, Hui Yang, Yu Zhao, Ming Wah Wong, Zhihai Ke, Ying-Yeung Yeung
Article
Chemistry, Organic
Wei Yao, Mingtai Sun, Yuannian Zhang, Hui Yang, Dong Liang, Haixia Wu, Runyan Ni, Ming Wah Wong, Dejian Huang
ORGANIC CHEMISTRY FRONTIERS
(2018)
Article
Chemistry, Organic
Germaine Pui Yann Kok, Hui Yang, Ming Wah Wong, Yu Zhao
Article
Chemistry, Multidisciplinary
Yi-Cen Ge, Hui Yang, Arne Heusler, Zhijie Chua, Ming Wah Wong, Choon-Hong Tan
CHEMISTRY-AN ASIAN JOURNAL
(2019)
Article
Chemistry, Organic
Cher Tian Ser, Hui Yang, Ming Wah Wong
JOURNAL OF ORGANIC CHEMISTRY
(2019)
Article
Chemistry, Physical
Hui Yang, Ming Wah Wong
JOURNAL OF PHYSICAL CHEMISTRY A
(2019)
Article
Chemistry, Multidisciplinary
Shenci Lu, Jun-Yang Ong, Hui Yang, Si Bei Poh, Xi Liew, Chwee San Deborah Seow, Ming Wah Wong, Yu Zhao
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2019)
Review
Biochemistry & Molecular Biology
Hui Yang, Ming Wah Wong
Article
Chemistry, Organic
Lihan Zhu, Hui Yang, Ming Wah Wong
Summary: The study focused on the enantioselective allylation mechanism of α-chloro glycinate catalyzed by squaramide organocatalysts using density functional theory. It was found that the catalytic reaction slightly favors the S(N)1 mechanism rather than the previous S(N)2 mechanism. Further investigation revealed that the S(N)1 mechanism might have been generally overlooked.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Qiong Wu, Weiwei Duan, Xiaoyu Jia, Hui Yang, Ming Wah Wong
Summary: Various strategies were employed to design novel thiabendazole derivatives in this study, with results showing that the introduction of different functional groups and substitutions can significantly affect the anti-corrosive properties of the compounds.
PROGRESS IN ORGANIC COATINGS
(2021)
Article
Chemistry, Organic
Hui Yang, Ming Wah Wong
Summary: The study investigates the reaction mechanisms of six catalyst-free hetero-Michael addition reactions in water using DFT calculations. Water molecules are directly involved in the transition states, playing a catalytic role in lowering the activation barrier, especially for thia-Michael reactions. The calculated low reaction barriers are in good agreement with the observed facile reactions, indicating the important role of water in these processes.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Si-Chen Zhang, Shengping Liu, Xia Wang, Shao-Jie Wang, Hui Yang, Lin Li, Binmiao Yang, Ming Wah Wong, Yu Zhao, Shenci Lu
Summary: We report an unprecedented stereoselective synthesis of triaryl-2pyrones from readily available starting materials. This method involves the atroposelective annulation of 2-aryketones with ynals under oxidative conditions. The annulation allows the construction of one or two axes in a single operation and affords axially chiral triaryl-2-pyrones with high enantioselectivity.
Article
Chemistry, Multidisciplinary
Mingan Chen, Hui Yang, Ming Wah Wong
Summary: Our study reveals a new mechanism for CO2 fixation onto cyclic carbonates, which differs from the commonly accepted mechanism with alternate epoxide and CO2 activation steps and a nested CO2 activation pathway. The general applicability of this mechanism was demonstrated through reactions catalyzed by two different catalysts.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Hui Yang, Choon-Hong Tan, Ming Wah Wong
Summary: Preorganization is a common strategy to align halogen bond donors, and designing neutral bidentate halogen bond donors connected by covalent bonds can deliver strong halogen bonds without competitive non-covalent interactions, potentially catalyzing important organic reactions involving soft anions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Shenci Lu, Xiaoxiao Song, Si Bei Poh, Hui Yang, Ming Wah Wong, Yu Zhao
CHEMISTRY-A EUROPEAN JOURNAL
(2017)