Article
Chemistry, Organic
Yu-Chen Guo, Kuei-Wei Chiu, Rong-Jie Chein
Summary: We developed a novel method for asymmetric cyclopropanation using (S)-(thiolan-2-yl)diphenylmethanol benzyl ether as an organocatalyst. The in situ generated sulfur ylide reacts with (E)-chalcones via a Johnson-Corey-Chaykovsky reaction, leading to the formation of various cyclopropanes with excellent yields and stereoselectivities. This environmentally friendly and efficient strategy utilizes reusable catalysts, offering a green approach for constructing cyclopropane scaffolds.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Panxia Zhao, Jie Chen, Nana Ma, Jingfei Chen, Xiangquan Qin, Chuanfei Liu, Fuquan Yao, Lishan Yao, Longyi Jin, Zhiqi Cong
Summary: The study demonstrates the efficient H2O2-dependent (R)-enantioselective epoxidation of unfunctionalized styrene and its derivatives by site-mutated variants of a unique non-natural P450BM3 peroxygenase in combination with a dual-functional small molecule. The synergistic use of protein engineering and an exogenous DFSM represents an effective strategy to control the enantioselectivity of styrene epoxidation, significantly expanding the chemical scope of P450 enzymes as useful bio-oxidative catalysts.
Article
Chemistry, Multidisciplinary
Gang Wang, Tian Chen, Kuiyong Jia, Wencheng Ma, Chen-Ho Tung, Lei Liu
Summary: We report a new titanium-catalyzed asymmetric oxidation method for the preparation of diverse chiral hydroxylamines. This method exhibits excellent selectivity and functional group compatibility. This finding provides a new platform for chiral hydroxylamines as design elements for drug discovery.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Applied
Gregory L. Beutner, David T. George
Summary: Cyclopropanes are important motifs in pharmaceutical compounds, and the Corey-Chaykovsky cyclopropanation offers a versatile and mild method for their synthesis. However, its application in large-scale syntheses is limited. This review examines the scope and limitations of the Bronsted-base-promoted Corey-Chaykovsky cyclopropanation with sulfur ylides, aiming to promote further advancements in this methodology.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2023)
Article
Chemistry, Organic
Qianwen He, Dong Zhang, Fengcai Zhang, Xiaohua Liu, Xiaoming Feng
Summary: An enantioselective epoxidation of a-substituted vinyl ketones was successfully achieved using a chiral N,N'-dioxide/Sc-III complex as the catalyst and 35% aq. H2O2 as the oxidant. This method greatly improved the efficiency and yield of the synthesis of various triazole antifungal agents, including isavuconazole and efinaconazole.
Article
Chemistry, Multidisciplinary
Kaixuan Wang, Chaoran Xu, Xinyue Hu, Yuqiao Zhou, Lili Lin, Xiaoming Feng
Summary: An efficient enantioselective [3+2] cycloaddition was achieved using a chiral N,N'-dioxide/Zn(ii) complex as a Lewis acid, resulting in the synthesis of a series of chiral oxa-bridged 3-spiropiperidines with high yields, excellent dr, and excellent ee values.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Hu Xiao, Shuang Dong, Yan Liu, Xiao-Qiong Pei, Hui Lin, Zhong-Liu Wu
Summary: New (R)-selective styrene monooxygenases have been identified, showing high enantioselectivity in converting styrene analogues into (R)-epoxides with purity up to >99% ee. Site 46 was identified as a critical residue affecting the enantioselectivity of SMOs, providing a valuable green alternative for the synthesis of enantiopure (R)-epoxides.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Andrea Pappalardo, Francesco P. Ballistreri, Rosa Maria Toscano, Maria Assunta Chiacchio, Laura Legnani, Giovanni Grazioso, Lucia Veltri, Giuseppe Trusso Sfrazzetto
Summary: Three new chiral Mn macrocycle catalysts were synthesized and tested in the enantioselective epoxidation reactions. The effect of a BINOL compound in the catalyst backbone was evaluated using Density Functional Theory (DFT) calculations.
Article
Chemistry, Physical
Dennis Verspeek, Sebastian Ahrens, Anke Spannenberg, Xiaodong Wen, Yong Yang, Yong-Wang Li, Kathrin Junge, Matthias Beller
Summary: A practical manganese(ii) catalyst system with an in situ generating method, using a commercially available bis(2-picolyl) amine ligand, enables efficient epoxidation of terminal aliphatic olefins with tert-butyl hydroperoxide as the oxidant. Crystallization experiments revealed the formation of two manganese solvent complexes with MeCN and H2O, respectively. Furthermore, a detailed investigation of the quinoline additive identified its crucial role in promoting the epoxide formation while negatively affecting its stability.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Isabel Guerrero, Clara Vinas, Isabel Romero, Francesc Teixidor
Summary: The cobalt bis(dicarbollide) complex Na[3,3'-Co(eta(5)-1,2-C2B9H11) (Na[1]) is an effective photoredox catalyst for the oxidation of alkenes to epoxides in water, exhibiting high efficiency and selectivity compared to other photosensitizers. By adjusting the catalyst loading, different product selectivity and conversion rates can be achieved in the reaction.
Article
Multidisciplinary Sciences
Mohammed Salim Mohammed, Homa Targhan, Kiumars Bahrami
Summary: A novel pseudo-homogeneous catalyst was designed and synthesized in this study. Amine-functionalized graphene oxide quantum dots (N-GOQDs) were prepared from graphene oxide (GO) through a simple oxidation fragmentation process. These N-GOQDs were then modified with quaternary ammonium hydroxide groups. The efficient catalytic performance of the synthesized N-GOQDs/OH- in the epoxidation reaction of alpha,beta-unsaturated ketones using aqueous H2O2 as the oxidant at room temperature was demonstrated. The procedure showed advantages such as the utilization of a green oxidant, high yields of the epoxide products, utilization of non-toxic reagents, and reusability of the catalyst without significant loss of activity.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Yasunori Toda, Takayuki Yoshida, Kaoru Arisue, Kazuaki Fukushima, Hiroyoshi Esaki, Ayaka Kikuchi, Hiroyuki Suga
Summary: This study reports on chiral Lewis acid-catalyzed asymmetric alcohol addition reactions to cyclic carbonyl ylides, generated from N-(alpha-diazocarbonyl)-2-oxazolidinones, using a dual catalytic system. A chiral quaternary heteroatom-substituted carbon center was successfully constructed, leading to unique heterobicycles with good yields and high stereoselection. Mechanistic studies revealed that Lewis acids activate alcohols, enabling enantioselective protonation of the carbonyl ylides.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Yiming Zhou, Ning Li, Wei Cai, You Huang
Summary: A new sequential reaction has been developed for the synthesis of tetra-substituted 2,3-dihydrofurans with generally excellent yields and good diastereoselectivities. Chiral propargyl sulfonium salt can also be used for the synthesis of optically active 2,3-dihydrofurans with good enantioselectivities. The reaction sequence is designed based on the in situ generated 107r-conjugated structures from the dearomatization of indole fragments and subsequent intramolecular 1,6-addition.
Review
Chemistry, Multidisciplinary
Sundaravel Vivek Kumar, Patrick J. Guiry
Summary: Asymmetric [3+2] cycloaddition reactions are interesting methods for synthesizing enantioenriched pyrrolidines with up to four stereocentres. Pyrrolidines are important compounds in biology and organocatalytic applications. This review summarizes the recent advancements in the enantioselective synthesis of pyrrolidines using metal catalysis, focusing on the [3+2] cycloadditions of azomethine ylides. The reactions are organized based on the type of metal catalysis and the complexity of the dipolarophile, highlighting their advantages and limitations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Jian Song, Wen-Hua Zheng
Summary: Despite the widespread use of boronic acids in catalysis, the development of efficient chiral boronic acids remains challenging. In this study, a rational design and a concise synthesis of new C2-symmetric disubstituted boronic acids, or borinic acids, were disclosed. These chiral borinic acids were found to be effective in achieving highly enantioselective desymmetrization of 2,2-disubstituted-1,3-propanediols, leading to chiral diols with a quaternary stereocenter. A range of substrates were successfully utilized in this reaction, providing chiral diols with high enantioselectivity. 11B NMR studies confirmed the presence of tetracoordinate borinate in the catalytic cycle, and a stereocontrol model was proposed.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Yu-Rong Chen, Annavareddi Naresh, Suh-Yuen Liang, Chun-Hung Lin, Rong-Jie Chein, Hsiao-Ching Lin
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Organic
Kuan-Lin Chen, Chen-Yu Lai, Mai-Truc Pham, Rong-Jie Chein, Yi Tang, Hsiao-Ching Lin
Article
Multidisciplinary Sciences
Jia-Tsrong Jan, Ting-Jen Rachel Cheng, Yu-Pu Juang, Hsiu-Hua Ma, Ying-Ta Wu, Wen-Bin Yang, Cheng-Wei Cheng, Xiaorui Chen, Ting-Hung Chou, Jiun-Jie Shie, Wei-Chieh Cheng, Rong-Jie Chein, Shi-Shan Mao, Pi-Hui Liang, Che Ma, Shang-Cheng Hung, Chi-Huey Wong
Summary: The COVID-19 pandemic has resulted in over 50 million confirmed cases and more than 1 million deaths globally as of November 2020. Currently, there are no effective antivirals approved by the FDA, posing a major challenge in vaccine development. Alternative treatments are urgently needed.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Organic
Ranuka T. Hewage, Rou-Jie Huang, Shu-Jung Lai, Ya-Chu Lien, Shao-Hsing Weng, Dehai Li, Yu-Ju Chen, Shih-Hsiung Wu, Rong-Jie Chein, Hsiao-Ching Lin
Summary: Meleagrin B is a terpene-alkaloid hybrid natural product with the conidiogenone and meleagrin scaffold. Derivatives of Meleagrin B show diverse biological activities, with compound 6 demonstrating stronger antibacterial effects against Staphylococcus aureus strains compared to compound 1.
Article
Chemistry, Inorganic & Nuclear
Ching-Pei Hsu, Yi-Hung Liu, Ramalingam Boobalan, Ya-Fan Lin, Rong-Jie Chein, Ching-Wen Chiu
Summary: A novel C-2-symmetric chiral tetra-coordinate aluminum cation was prepared in this study, showing high Lewis acidity and effective catalytic conversion, although the enantioselectivity was compromised by the presence of a labile N-Al bond.
Article
Chemistry, Organic
Ramalingam Boobalan, Rong-Jie Chein
Summary: The emergence of second-generation sulfur-stabilized borenium cations by halophilic Lewis acid SnCl4 results in highly active chiral Lewis acids that are effective catalysts for [4 + 2] cycloaddition, exhibiting excellent enantioselectivity for a variety of substrates and demonstrating good catalytic efficiency.
Article
Chemistry, Inorganic & Nuclear
Ding-Nan Shih, Ramalingam Boobalan, Yi-Hung Liu, Rong-Jie Chein, Ching-Wen Chiu
Summary: In recent years, a tricoordinate borenium ion has been studied for its applications in Lewis acid catalysis, as well as in the development of asymmetric catalysis mediated by a chiral borenium ion. Chloroborane masked borenium ions have been prepared to stabilize the electron-deficient boron atom and utilized as catalysts for enantioselective Diels-Alder cycloaddition reactions. Additionally, the stereoselectivity of the cycloaddition can be controlled and improved by the coordination of SnCl4 at the bridging chloride of the borenium ion.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Pei-Tung Cheng, Yu-Hsun Tseng, Rong-Jie Chein
Summary: A new class of chiral tetrahydroselenophene-based compounds were synthesized and demonstrated to catalyze asymmetric cyclopropanation reactions with high enantioselectivities.
Article
Chemistry, Multidisciplinary
Tzu-Ho Chen, Chien-Ting Chen, Chi-Fang Lee, Rou-Jie Huang, Kuan-Lin Chen, Yuan-Chun Lu, Suh-Yuen Liang, Mai-Truc Pham, Yerra Koteswara Rao, Shih-Hsiung Wu, Rong-Jie Chein, Hsiao-Ching Lin
Summary: (-)-Antrocin is a potent antiproliferative compound produced by Antrodia cinnamomea. The biosynthetic gene cluster and pathway for its production were characterized. The terpene cyclase AncC was found to biosynthesize the sesquiterpene albicanol from farnesyl pyrophosphate, while AncA converted it into a different compound.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Yu-Chen Guo, Kuei-Wei Chiu, Rong-Jie Chein
Summary: We developed a novel method for asymmetric cyclopropanation using (S)-(thiolan-2-yl)diphenylmethanol benzyl ether as an organocatalyst. The in situ generated sulfur ylide reacts with (E)-chalcones via a Johnson-Corey-Chaykovsky reaction, leading to the formation of various cyclopropanes with excellent yields and stereoselectivities. This environmentally friendly and efficient strategy utilizes reusable catalysts, offering a green approach for constructing cyclopropane scaffolds.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Kuei-Wei Chiu, Yu-Hsun Tseng, Ying-Xin Li, Rong-Jie Chein
Summary: In this study, a novel biomimetic synthesis of clavicipitic acid diastereomers was reported, utilizing a DDQ-mediated crossdehydrogenative coupling (CDC) reaction. The synthesis involved Suzuki coupling for prenylation and an intramolecular CDC reaction for the construction of the azepinoindole core. The trans isomer was obtained as the major product, and the two diastereomers were separable. The CDC reaction conditions were investigated, and a plausible mechanism for diastereoselectivity was proposed.
Article
Multidisciplinary Sciences
Chia-Yi Lin, Kuo-Yen Huang, Shih-Han Kao, Ming-Shiu Lin, Chih-Chien Lin, Shuenn-Chen Yang, Wei-Chia Chung, Ya-Hsuan Chang, Rong-Jie Chein, Pan-Chyr Yang
Summary: In this study, a small molecule drug called PIK-93 was discovered to modulate the tumor microenvironment by reducing PD-L1 levels and enhancing the cytotoxicity of M1 macrophages. Combined with anti-PD-L1 antibodies, PIK-93 treatment enhanced T cell activation, inhibited tumor growth, and increased the recruitment of tumor-infiltrating lymphocytes.
Article
Chemistry, Multidisciplinary
Rou-Jie Huang, Tiow-Gan Ong, Rong-Jie Chein
Summary: This paper presents the first successful total synthesis of pikrosalvin, a compound naturally derived from Salvia officinalis, using a biomimetic strategy. The study sets the stage for future biological and pharmacological investigations of pikrosalvin.
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Soumendranath Mukhopadhyay, Ramalingam Boobalan, Rong-Jie Chein
Summary: The generation of sulfur-stabilized borenium cations using the halophilic Lewis acid SnCl4 leads to the formation of excellent Lewis acid oxathiaborolium pentachlorostannate, which can be efficiently used as a catalyst for the [2 + 2] cycloaddition reaction to synthesize ring-fused cyclobutanes with quaternary stereogenic centers.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Suhas Ravindra Bavikar, Hong-Jay Lo, Chebolu Naga Sesha Sai Pavan Kumar, Rong-Jie Chein
Summary: Herein, an enantioselective total synthesis of (-)-panduratin D, a novel secondary metabolite against human pancreatic cancer cells, is reported. The synthesis was completed in nine steps and involved various key features including Sonogashira coupling, anionic Snieckus-Fries rearrangement, directed ortho metalation, tandem Si -> C alkyl rearrangement/Claisen-Schmidt condensation, and chiral boron complex-promoted asymmetric Diels-Alder cycloaddition.
CHEMICAL COMMUNICATIONS
(2022)
