Article
Chemistry, Multidisciplinary
Stuart C. D. Kennington, Saul F. Teloxa, Miguel Mellado-Hidalgo, Oriol Galeote, Sabrina Puddu, Marina Bellido, Pedro Romea, Felix Urpi, Gabriel Aullon, Merce Font-Bardia
Summary: A direct and asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalyzed by chiral nickel(II) complexes was reported. The reaction gives high yields of O-TIPS-protected anti-aldol adducts with remarkable stereocontrol and atom economy. The removal of the achiral scaffold provides enantiomerically pure intermediates with synthetic interest for producing anti-alpha-amino-beta-hydroxy and alpha,beta-dihydroxy carboxylic derivatives, with theoretical calculations explaining the observed high stereocontrol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Hyoung Min Yeo, Sungmin Kang, Taek Hyeon Kim
Summary: The first chiral proline amide-isothiouronium based bifunctional organocatalyst was developed, showing high to quantitative yields in aldol products with excellent control performance of diastereoselectivities and enantioselectivity.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Saul F. Teloxa, Miguel Mellado-Hidalgo, Stuart C. D. Kennington, Pedro Romea, Felix Urpi, Gabriel Aullon, Merce Font-Bardia
Summary: A direct and asymmetric aldol reaction between N-azidoacetyl-1,3-thiazolidine-2-thione and aromatic aldehydes catalyzed by a chiral nickel(II)-Tol-BINAP complex has been developed. The reaction gives anti alpha-azido-beta-silyloxy adducts with excellent stereocontrol and high yields. The removal of thiazolidinethione allows for the synthesis of a wide array of enantiomerically pure derivatives, providing a new route to di- and tripeptide blocks containing a beta-aryl-beta-hydroxy-alpha-amino acid.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Santanu Mondal, Ravindra D. Aher, Venkati Bethi, Yu-Ju Lin, Tohru Taniguchi, Kenji Monde, Fujie Tanaka
Summary: This study reports amine-based catalyst systems for the enantioselective Mannich reactions of pyruvates as nucleophiles. The reactions of pyruvates and cyclic sulfonylimines yielded the desired Mannich products, including those with tetrasubstituted carbon centers, in high yields and enantioselectivities. The choice of acid in the amine-based catalyst system played a key role in the formation of Mannich products with high enantioselectivities.
Article
Chemistry, Organic
Yiran Mo, Xuehuan Zhang, Yongqi Yao, Cong Duan, Ling Ye, Zhichuan Shi, Zhigang Zhao, Xuefeng Li
Summary: A sulfa-Michael/aldol/lactonization cascade reaction has been established to construct isotetronic acid-fused thiochromanes in a highly stereoselective fashion (>= 11:1 dr, 35-98% ee). The tricyclic products were obtained in 35-99% isolated yields in the presence of a bifunctional squaramide. Three reactive sites of beta,gamma-unsaturated alpha-ketoester, including the less-explored ester carbonyl group, were sequentially utilized to construct two fused heterocycles in a one-pot operation.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Biochemical Research Methods
Ningning Zhang, Changzhu Wu
Summary: This study proposes an advanced artificial enzyme by polymeric modularity as an efficient aldolase mimic for aqueous asymmetric aldol reactions. The tailored conjugates exhibited remarkable catalytic performance and excellent selectivity. Additionally, the artificial enzyme showed high tolerance and reusability.
ACS SYNTHETIC BIOLOGY
(2022)
Article
Chemistry, Organic
Dattatraya N. Bhangare, Rohit G. Shinde, Pushpalata D. Pawar, Milind D. Nikalje, Mahendra N. Lokhande
Summary: This method utilizes Sc(OTf)(3) as a catalyst and (-)-menthol as a chiral auxiliary to achieve remarkable diastereoselectivity in the asymmetric aldol reaction. It offers mild reaction conditions, high yields, and excellent diastereoselectivity with a variety of substituted aromatic aldehydes. Sc(OTf)(3) demonstrates excellent diastereoselectivity at -45 degrees C under different reaction conditions.
JOURNAL OF HETEROCYCLIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Nikhil Srivastava, Hyun-Joon Ha
Summary: A straightforward and highly diastereoselective synthesis of beta-(aziridin-2-yl)-beta-hydroxy ketones was achieved via the Mukaiyama aldol reaction, with excellent yields and diastereoisomeric ratio. These ketones were further utilized in the synthesis of various alkaloids, demonstrating their versatile applications in organic synthesis.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Physical
Pratikkumar Lakhani, Chetan K. Modi
Summary: Asymmetric catalysis is a process where less than stoichiometric concentrations of a catalyst are used to preferentially synthesize one enantiomer over the other. This review article provides a concise summary of the current applications, methodologies, and approaches to asymmetric catalysis under heterogeneous conditions. It demonstrates the technique's ability to use chiral catalysts without diminishing activity or enantioselectivity. The review article also presents numerous examples of industrial and laboratory chemo catalyzed processes.
MOLECULAR CATALYSIS
(2023)
Article
Chemistry, Organic
Li Hui, Yin Liang
Summary: Vinylogous reaction is an efficient tool to introduce new functional groups at the gamma-position or more remote positions of the parent functional group. The resulting highly functionalized structures are widely present in natural products, biologically active compounds, and pharmaceuticals, and serve as important synthetic intermediates. The focus of our group is the development of efficient direct vinylogous reactions using copper catalysts, particularly in the catalytic asymmetric variants.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nicolaj Inunnguaq Jessen, Maksimilian Bura, Giulio Bertuzzi, Karl Anker Jorgensen
Summary: An efficient and stereoselective synthesis of chiral cycl[3.2.2]azines has been achieved through the rational design and utilization of novel (E)-3-benzylidene-3H-pyrrolizines in iminium-ion catalysis. The method allows for incorporation of diverse enals and the obtained products can undergo selective transformations while retaining stereochemical information established in the [8+2] cycloaddition.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Yujiro Hayashi
Summary: The aldol reaction is a significant carbon-carbon bond-forming reaction in organic chemistry. The use of trifluoromethyl-substituted diarylprolinol as an organocatalyst has been found to be effective in promoting cross-aldol reactions with excellent selectivities.
Article
Chemistry, Organic
Akram Hussain, Dhevalapally B. Ramachary
Summary: We developed a simple and practical protocol for the chemoselective coupling of optically active functionally rich 2-aroylcyclopropanecarbaldehydes with various CH acids or active methylene compounds. This metal-free, organocatalytic selective reductive C-C coupling method offers advantages such as no epimerization, no ring opening, high carbonyl control, and large substrate scope. The resulting chiral products can serve as building blocks for the synthesis of value-added small molecules, natural products, pharmaceuticals, and their analogues.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Aimin Xu, Xiaoyu Zhou, Rimei Zheng, Zhijing Zhang, Xinru Yin, Kemiao Hong, Zhuofeng Ke, Yu Qian, Wenhao Hu
Summary: In this study, a chiral dirhodium complex was used as a catalyst for asymmetric annulation reactions, leading to the synthesis of chiral 2,3-dihydropyrans with excellent diastereos-electivities and enantioselectivities. The high stereoselectivity of the products was elucidated through experimental and computational studies. Furthermore, these chiral products exhibited potent antiproliferation activity against three cancer cell lines.
SCIENCE CHINA-CHEMISTRY
(2022)
Review
Biochemistry & Molecular Biology
Arianna Quintavalla, Davide Carboni, Marco Lombardo
Summary: In 1971, a new asymmetric intramolecular aldol reaction catalyzed by the natural amino acid proline was discovered independently by chemists from Hoffmann-La Roche and Schering AG. This reaction later became known as the Hajos-Parrish-Eder-Sauer-Wiechert reaction. In 2000, it was found that L-proline could also catalyze intermolecular aldol reactions with significant enantioselectivities, and in the same year, imidazolidinones derived from natural amino acids were found to efficiently catalyze asymmetric Diels-Alder cycloadditions, marking the birth of modern asymmetric organocatalysis. In 2005, the use of diarylprolinol silyl ethers for the asymmetric functionalization of aldehydes was proposed, further advancing the field of asymmetric organocatalysis.
Article
Oncology
Hongsheng Wang, Jie Wan, Huangao Zhou, Jianing Xu, Yunpeng Lu, Xiaoyun Ji, Yizheng Yao, Hou Chao, Jun Zhang, Xiaochun Zhang, Shun Yao, Yinqiu Wu
Summary: This review discusses the impact of the GBM microenvironment on T-cell subsets and strategies to overcome immunosuppression.
Article
Chemistry, Medicinal
Nguyen Thi Tu Oanh, Pham Tran Thu Ha, Tran Huu Giap, Vu Thi Kim Oanh, Nguyen Thi Minh Hang, Nguyen Van The, Dinh Ngoc Thuc, Donatella Fedeli, Rosita Gabbianelli, Phung Thanh Huong, Nguyen Van Hung, Le Nguyen Thanh
CHEMISTRY OF NATURAL COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Thuc Ngoc Dinh, Mai Vu Thi Ha, Luong Ngo Xuan, Huan Trinh Thi, Huong Nguyen Thi, Mai Nguyen Thi Ngoc, Giap Tran Huu, Oanh Vu Thi Kim, Thanh Le Nguyen
Summary: Phytochemical investigation of Rourea oligophlebia stems led to the isolation of a new 2-pyrrolidone alkaloid and several known compounds. Some of the isolated compounds showed promising antimicrobial and cytotoxic activities, indicating their potential pharmaceutical value.
JOURNAL OF CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Danuta Jantas, Janusz Malarz, Thanh Nguyen Le, Anna Stojakowska
Summary: Flavonols, such as kaempferitrin and alpha-rhamnoisorobin, have shown neuroprotective effects in vitro experiments on SH-SY5Y cells damaged by H2O2 and 6-OHDA. The tested flavonols were not effective in counteracting doxorubicin-induced cytotoxicity. Inhibition of the PI3-K/Akt pathway abolished the neuroprotective effect of the investigated flavonols.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Klaudia Michalska, Agnieszka Galanty, Thanh Nguyen Le, Janusz Malarz, Nguyen Quoc Vuong, Van Cuong Pham, Anna Stojakowska
Summary: Maesa membranacea, a plant species used in traditional ethnobotany knowledge in northern and central Vietnam, was found to contain two new polyesterified ursane triterpenes and two known apocarotenoids. The newly isolated triterpenoids showed cytotoxic activity against prostate cancer cell lines and affected the viability of normal prostate epithelium cells.
Article
Physics, Atomic, Molecular & Chemical
Haipan Xiang, Yunpeng Lu, Hongwei Song, Minghui Yang
Summary: In this study, the hydrogen abstraction reaction between OH and H2S was investigated using a wave packet approach. The reaction was found to be barrier-less at low collision energies and activated with a well-defined barrier at high collision energies. Excitation of the stretching modes of H2S enhances the reactivity more than excitation of the bending mode, which can be explained by the coupling strength between each normal mode and the reaction coordinate. Additionally, the mode-specific rate constant exhibits a remarkable non-Arrhenius temperature dependence.
CHINESE JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Surgery
Xiang Zhong, Yunpeng Lu, Xu Yin, Quhui Wang, Feiran Wang, Zhixian He
Summary: This study identified independent risk factors for central lymph node metastasis (CLNM) in patients with clinical central lymph node-negative papillary thyroid carcinoma (PTC) and established a risk scoring model to predict CLNM. Preoperative evaluation was emphasized for selecting the best surgical plan.
Article
Chemistry, Multidisciplinary
Kai Leong Goh, Atsushi Goto, Yunpeng Lu
Summary: The Ramprasad group recently reported a QSPR model for predicting Egap values of polymers, which showed good performance on the test set. In this paper, a new QSPR model called LGB-Stack is introduced, which uses a light gradient boosting machine. The model combines multiple weak models into a strong final model using molecular fingerprints and recursive feature elimination. Experimental results demonstrate the high predictive accuracy of the LGB-Stack model on the test set.
Article
Biochemistry & Molecular Biology
Milena Popova, Boryana Trusheva, Ralitsa Chimshirova, Daniela Antonova, Kamelia Gechovska, Le Nguyen Thanh, Nguyen Thi Phuong Lien, Diep Thi Lan Phuong, Vassya Bankova
Summary: The present study analyzed and compared the chemical profile and antioxidant capacity of propolis from different bee species and regions. The results revealed differences in the chemical composition and antioxidant activity of propolis from different stingless bee species. This study provides important insights into the characteristics and potential applications of propolis from different bee species.
Article
Chemistry, Multidisciplinary
Shuyang Wu, Jenica Marie L. Madridejos, Jinn-Kye Lee, Yunpeng Lu, Rong Xu, Zhengyang Zhang
Summary: Graphitic carbon nitride (g-C3N4) has been extensively studied due to its unique structure, synthetic route, and excellent photocatalytic performance. In this study, ultrathin g-C3N4 nanosheets were fabricated and their catalytic activities and kinetics were investigated using single-molecule fluorescence microscopy. The results revealed that the wrinkle and edge structures exhibited superior photocatalytic activity compared to the basal plane structure. The findings of this study contribute to the understanding of site-specific catalytic dynamics on g-C3N4 and the design of efficient solar-to-chemical energy conversion.
Article
Biochemistry & Molecular Biology
Heewon An, Le Nguyen Thanh, Le Quoc Khanh, Se Hwan Ryu, Solip Lee, Sang Won Yeon, Hak Hyun Lee, Ayman Turk, Ki Yong Lee, Bang Yeon Hwang, Mi Kyeong Lee
Summary: This study investigated the constituents and biological activity of Cratoxylum formosum ssp. pruniflorum. The extract of its leaves, roots, and stems showed antioxidant and alpha-glucosidase inhibitory activity. The metabolite profiles analysis revealed a significant difference between the roots and leaves, while the roots and stems were similar. Purification of the roots and leaves resulted in the isolation of 25 compounds, including xanthones, flavonoids, a benzophenone, and a phenolic compound.
Article
Chemistry, Medicinal
Sherwin S. S. Ng, Yunpeng Lu
Summary: Oral bioavailability is an important pharmacokinetic property in drug discovery. Computational models using molecular descriptors, fingerprints, and machine-learning have been developed, but determining the right molecular descriptors requires domain expert knowledge and time for feature selection. Graph neural networks (GNN) can automatically extract important features, and in this study, we used GNN's automatic feature selection to predict oral bioavailability. By utilizing transfer learning and pre-training a model to predict solubility, we achieved improved prediction performance with average accuracy of 0.797, F1 score of 0.840, and AUC-ROC of 0.867, outperforming previous studies on predicting oral bioavailability with the same test data set.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Biology
Diep Thi Lan Phuong, Nguyen Van Phuong, Nguyen Le Tuan, Nguyen Thanh Cong, Nguyen Thu Hang, Le Nguyen Thanh, Vu Thi Hue, Nguyen Quoc Vuong, Nguyen Thi Thu Ha, Milena Popova, Boryana Trusheva, Vassya Bankova
Summary: The chemical investigation of Homotrigona apicalis propolis from Vietnam led to the isolation of nine compounds, including sesquiterpenes, triterpenes, and xanthones. Some compounds showed good antibacterial activity and cytotoxic effects against cancer cell lines. The binding affinity of xanthones with EGFR and HER2 was determined, and compounds showed potential α-glucosidase inhibitory activities.
Article
Chemistry, Multidisciplinary
Shuyang Wu, Jenica Marie L. Madridejos, Jinn-Kye Lee, Rong Xu, Yunpeng Lu, Zhengyang Zhang
Summary: In this study, single-molecule fluorescence microscopy was used to quantify the photo-oxidation reaction kinetics on g-C3N4. The results showed that the wrinkle structure exhibited the highest reactivity and direct dissociation rate, while the basal plane had the highest affinity to reactants and products, as well as an indirect dissociation rate constant, followed by edges and wrinkles.
CHEMICAL COMMUNICATIONS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Lang Xu, Li-Jie Xu, Cong-Tian Zhang, Wen-Jie Wu, Hong-Lin Zhang, Yun-Peng Lu, Bo Li
Summary: In this paper, a 4-way coupled-line wideband Wilkinson power divider is designed for microwave communication system, with a compact dimension and good performance.
2022 IEEE MTT-S INTERNATIONAL MICROWAVE WORKSHOP SERIES ON ADVANCED MATERIALS AND PROCESSES FOR RF AND THZ APPLICATIONS, IMWS-AMP
(2022)
Article
Chemistry, Organic
Faiza Diaba, Gisela Trenchs
Summary: The first violet light-mediated synthesis of gamma- and delta-lactams from N-alkenyl trichloroacetamides is reported in this paper. The reactions are conducted in tetrahydrofuran or 2-methyltetrahydrofuran as the sole solvent without catalysts or additives, under non-anhydrous conditions in an air atmosphere where the solvent serves as the radical initiator.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Feroze Hussain, Sajjad Ahmed, Ashiq Hussain Padder, Qazi Naveed Ahmed
Summary: This study reports a novel and efficient one-pot synthesis method for mixed phosphorotrithioates, which does not require supplementary additives and shows broad applicability.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Hyunjin Oh, Ikyon Kim
Summary: A new 1,2,4-triazole-pyrrolo[1,2-a]pyrazine hybrid system, 6-acylpyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazine, was synthesized using a catalyst-free method. This method involved sequential exposure of pyrrole-2-carbonitrile-derived substrates to DMF-DMA and acyl hydrazide, resulting in the formation of acylated pyrazine and 1,2,4-triazole rings, enabling the installation of various substituents at specific positions on the core skeleton.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Ming Yan, Si-fan Wang, Yong-po Zhang, Jin-zhong Zhao, Zhuo Tang, Guang-xun Li
Summary: Here we developed an efficient photocatalytic approach for the convenient preparation of sulfinamides. The reaction allows for the gram-scale preparation of sulfinamides and the one-pot synthesis of various sulfonyl amides.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Farzaneh Bandehali-Naeini, Zahra Tanbakouchian, Noushin Farajinia-Lehi, Nicolas Mayer, Morteza Shiri, Martin Breugst
Summary: Two tandem catalytic systems were developed for the synthesis of novel 3,4-disubstituted maleimides using the same Ugi adducts. Different maleimide structures can be synthesized using either Pd or Cu catalysis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Tanya Raghava, Anjan Chattopadhyay, Subhadeep Banerjee, Nivedita Sarkar
Summary: Amine substitution of two ortho fluorine atoms of tetrafluoroterephthalonitrile through SNAr chemistry is easily achievable. But further fluorine substitution is only possible under forcing conditions, yielding valuable fluorophores for bioimaging.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Review
Chemistry, Organic
Anju Chadha, Santosh Kumar Padhi, Selvaraj Stella, Sowmyalakshmi Venkataraman, Thangavelu Saravanan
Summary: Alcohol dehydrogenases are enzymes that use cofactors for oxidation or reduction reactions of alcohols or carbonyl compounds. They are utilized in green chemistry and have applications in the production of pharmaceuticals. Recombinant enzymes have solved the challenge of producing purified enzymes in large quantities. Engineered alcohol dehydrogenases have been used in asymmetric synthesis in industry. Various methods have been established for regenerating expensive cofactors to make the enzymatic process more efficient and economically viable.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
