Article
Chemistry, Organic
Shen Li, Hui Zhou, Benjamin List
Summary: We have synthesized a new spirocyclic quaternary ammonium salt with axial chirality. Enantiopure material was achieved through fractional crystallization of the corresponding (R, R)-tartrate salt. The application of this chiral quaternary ammonium salt in phase-transfer catalytic asymmetric alkylation of glycinate Schiff base was investigated.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Katharina Roeser, Bettina Berger, Michael Widhalm, Mario Waser
Summary: An asymmetric protocol was developed to access a series of orthogonally functionalized acyclic chiral target molecules containing a quaternary stereogenic center through enantioselective alpha-alkylation catalyzed by chiral ammonium salts. Enantioselectivities up to e.r.=97.5 : 2.5 were achieved using just 1 mol % of Maruoka's spirocyclic ammonium salt catalysts, allowing for further functional group manipulations of the products.
Article
Chemistry, Physical
Grazia Bencivenni, Nathalie Saraiva Rosa, Paolo Grieco, Malachi W. Gillick-Healy, Brian G. Kelly, Brendan Twamley, Mauro F. A. Adamo
Summary: This study provides physical evidence confirming that quaternary ammonium species interact with anions through a set of directional ion-dipole cooperative hydrogen bonding interactions. This finding is important for the rational design of catalysts and understanding these species in asymmetric catalysis.
Article
Chemistry, Organic
Xinduo Sun, Chaoji Xiong, Fanrui Zhou, Kun Liang, Chunhua Wu, Xiaoping Rao, Qian Chen
Summary: The asymmetric addition of terminal alkynes catalyzed by a transition metal to isatins is an efficient and economical method for synthesizing 3-alkynyl-3-hydroxy-2-oxindoles. Using a new dimeric chiral quaternary ammonium derived from quinine as the cationic inducer, under mild conditions, the desired chiral compounds can be obtained in good to high yields with high enantioselectivity (<= 99% ee), and a variety of aryl-substituted terminal alkynes and substituted isatins are tolerated in this reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Jian-Qiang Chen, Qi Chen, Baofu Chen, Jie Wu
Summary: A direct photoredox catalyzed radical-triggered tandem cyclization of 1,7-enynes with alkyloxalyl chlorides is developed, enabling the preparation of dihydropyranones containing all-carbon quaternary centers through alkoxycarbonylation/6-exo-dig cyclization/6-endo-trig cyclization with 1,7-enynes under mild conditions. Importantly, this approach provides a new route to polysubstituted dihydropyranones.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Review
Chemistry, Applied
Hongxiang Li, Honglei Liu, Hongchao Guo
Summary: Quaternary phosphonium salts are extensively used as Lewis acid organocatalysts in organic synthesis, particularly for Mannich, Strecker, and Friedel-Crafts reactions, allowing the construction of structurally diverse and synthetically useful architectures.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Jiangyan Tian, Wendian Li, Ruihao Li, Lin He, Hui Lv
Summary: The nickel/(S)-t-Bu-PHOX complex catalyzed asymmetric arylative cyclization of N-alkynones has successfully delivered 1,2,3,6-tetrahydropyridines containing a chiral tertiary alcohol in high yields and excellent enantioselectivities, providing efficient access to chiral tetrahydropyridine and piperidine analogues.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Marvin Titze, Juliane Heitkaemper, Thorsten Junge, Johannes Kaestner, Rene Peters
Summary: Enantiopure secondary alcohols are high-value synthetic building blocks, and a new concept for catalytic hydroboration has been proposed with exceptional catalytic turnover numbers. The catalyst, accessible in few steps, is stable, recyclable, and efficient for at least 10 times of reuse.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ju-Song Yang, Ka Lu, Chen-Xiao Li, Zu-Hang Zhao, Xiao-Ming Zhang, Fu-Min Zhang, Yong-Qiang Tu
Summary: Novel asymmetric mono- and dialkylation reactions of α-substituted 2,5-diketopiperazines catalyzed by new chiral spirocyclic-amide-derived triazolium organocatalysts have been developed, leading to enantioenriched products and providing a new synthetic approach.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Biochemistry & Molecular Biology
Milena Krstic, Sergio Rossi, Miguel Sanz, Alessandra Puglisi
Summary: The enantioselective synthesis of optically active alpha-amino acid derivatives using achiral Schiff base esters has been well-developed in batch, and recent studies have explored its application in continuous flow systems. Two different methodologies were investigated, with liquid-liquid phase transfer catalysis showing slightly better productivity and solid-liquid phase transfer catalysis proving more advantageous in terms of productivity and space-time yield. The continuous flow system also allowed for the isolation of the benzylated product without any additional work up, simplifying the process. Both methods showed high enantioselectivity, with up to 93% ee achieved in the continuous flow phase transfer benzylation promoted by Maruoka catalyst.
Article
Chemistry, Applied
Andreas Eitzinger, Jan Otevrel, Victoria Haider, Antonio Macchia, Antonio Massa, Kirill Faust, Bernhard Spingler, Albrecht Berkessel, Mario Waser
Summary: In this study, chiral 3,3-disubstituted isoindolinones were synthesized using ammonium salt catalysis, yielding a variety of differently substituted CF3S- and RS-derivatives with high enantioselectivities. Additionally, a racemic synthesis of F-containing products was achieved for the first time, producing a stable alpha-F-alpha-amino acid derivative.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Christopher Mairhofer, Mario Waser
Summary: Dibenzoylperoxide was found to be a versatile oxidant for reactions of phenol derivatives with NaN3 catalyzed by quaternary ammonium iodide or bromide. The use of iodides allowed for efficient benzylic azidations, while the use of bromides allowed for dearomative azidations. Both methods have been successfully applied to various phenol derivatives, and an enantioselective variant using chiral quat. ammonium bromides has been demonstrated.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Physical
Meng-Yu Rong, Jing Nie, Shen Li, Jun-An Ma
Summary: We synthesized a new class of chiral quaternary ammonium salts and used them as catalysts in phase-transfer catalytic asymmetric alkylation. By employing these catalysts, we obtained a series of chiral fluorinated aromatic alpha-amino acid derivatives with high yields and enantioselectivities.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Multidisciplinary
Fabian Scharinger, Adam Mark Palvoelgyi, Melanie Weisz, Matthias Weil, Christian Stanetty, Michael Schnuerch, Katharina Bica-Schroeder
Summary: In this study, we propose a novel approach for various asymmetric transformations of cyclic enones. By optimizing the catalyst components, we have developed a particularly powerful and versatile organocatalyst that shows excellent stereocontrol. Furthermore, a simple change in the diamine's configuration allows access to both product antipodes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Marta Solas, Samuel Suarez-Pantiga, Roberto Sanz
Summary: This study describes the asymmetric synthesis of cyclopentachromenones from gold-catalyzed reaction of readily available skipped alkenynones. The cascade reaction involves an initial anti-Michael hydroarylation and a subsequent Nazarov cyclization. Excellent enantiomeric ratios and chemical yields are achieved under mild reaction conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Haoran Hong, Hongyu Wang, Changwu Zheng, Gang Zhao, Yongjia Shang
Summary: The asymmetric Michael addition reactions catalyzed by phosphine-containing multiple hydrogen bonds achieved high yields and excellent enantioselectivities, providing new paradigms for the synthesis of chiral quaternary carbon centers in indanone derivatives.
CHINESE CHEMICAL LETTERS
(2021)
Article
Immunology
Peeraphong Lertnimitphun, Wenhui Zhang, Wenwei Fu, Baican Yang, Changwu Zheng, Man Yuan, Hua Zhou, Xue Zhang, Weizhong Pei, Yue Lu, Hongxi Xu
Summary: The study demonstrated that safranal can alleviate OVA-induced asthma, inhibit mast cell activation, and reduce PSA reaction. The possible mechanism involves the inhibition of the MAPKs and NF-kappa B pathways.
FRONTIERS IN IMMUNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Jun Liu, Longhui Yu, Changwu Zheng, Gang Zhao
Summary: The asymmetric synthesis of 2,2-difluorinated tetrahydrofurans was achieved through palladium-catalyzed enantioselective formal [3+2] cycloaddition, resulting in enantioenriched products with up to 98% selectivity. The use of readily available (R)-BINAP ligand at a low loading enabled the production of a wide variety of difluorinated compounds in moderate to high yields, with the ability to obtain both chiral diastereomers in a single sequence.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Biochemistry & Molecular Biology
Qing Huang, Youyi Wang, Huaimo Wu, Man Yuan, Changwu Zheng, Hongxi Xu
Summary: Xanthones are a diverse group of secondary metabolites found in various plants, fungi, lichens, and bacteria, with a majority in families such as Gentianaceae, Polygalaceae, and Clusiaceae. Xanthone glucosides, an important branch of xanthones, have potential improved characteristics after glycosylation. This review provides a comprehensive literature survey on naturally occurring xanthone glucosides, exploring their isolation, structure, bioactivity, and synthesis.
Article
Chemistry, Organic
Xueying Wang, Yeelin Phang, Jiling Feng, Song Liu, Hong Zhang, Wenwei Fu, Hua Zhou, Gang Xu, Hongxi Xu, Changwu Zheng
Summary: The asymmetric total synthesis of five biologically significant polycyclic polyprenylated acylphloroglucinols (PPAPs), including garcinol and cambogin, was achieved through a highly diastereoselective and stereodivergent strategy. An efficient cascade Dieckmann cyclization was employed to construct the bicyclo[3.3.1]nonane core in one step. The synthesis provided a general approach toward the chiral endo-type B PPAPs and their C-30 diastereomers in a single sequence, which resolved the challenges of the absolute configuration determination/structural revision of PPAPs bearing exocyclic stereocenters.
Article
Chemistry, Applied
Longhui Yu, Jun Liu, Hongyu Wang, Lijun Xu, Yufei Wu, Changwu Zheng, Gang Zhao
Summary: An asymmetric Dieckmann condensation towards spirocyclic oxindoles and aza-oxindoles catalyzed by amino acid-derived phosphonium salt has been developed, which expands the applicability of asymmetric phosphonium salt catalysis in the production of 1,3-dicarbonyl compounds. The reaction features mild conditions, low catalyst loading, and a broad substrate scope. Control experiments confirmed the necessity of the catalyst's phosphonium skeleton and H-bonding site.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Review
Chemistry, Multidisciplinary
Youyi Wang, Qing Huang, Li Zhang, Changwu Zheng, Hongxi Xu
Summary: Clusiaceae plants contain a wide range of biologically active metabolites, particularly biphenyl compounds, which have demonstrated positive effects on various ailments. The study of biphenyls from Clusiaceae has sparked significant interest and research in their chemical structure, medicinal potential, and biological effects.
FRONTIERS IN CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Xueying Wang, Jiling Feng, Rong Wu, Jiaqi Tan, Qing Huang, Yeelin Phang, Li Zhang, Wenwei Fu, Hongxi Xu, Changwu Zheng
Summary: This research aims to thoroughly evaluate the potential of Garcinol and its analogues in terms of synthesis, structural diversity, biosynthesis, and prevention of carcinoma cell proliferation. Garcinopicrobenzophenone and eugeniaphenone were synthesized and their structures were clarified. The synthesis also proposed a possible biogenetic synthesis pathway. The cytotoxicity and mechanism of action of the polyisoprenylated benzophenones were studied, showing potential as chemotherapeutic agents in pancreatic cancer cells.
BIOORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Guangzheng Tian, Mingtong Ji, Fan Wu, Guan Wang, Changwu Zheng, Xiaoyu Wu
Summary: A diastereo- and enantioselective propargylic substitution reaction was performed between propargylic carbonates and 2,2,2-trifluoroethyl-substituted nitroisoxazoles catalyzed by a Cu-pybox complex. This method enables the preparation of propargylation products with two contiguous stereogenic centers, one of which is a chiral trifluoromethyl-bearing carbon. The desired products were produced in high yields with good to excellent diastereo- and enantioselectivities in most cases.
Article
Chemistry, Analytical
Gan Chen, Hong Zhang, Jiaming Jiang, Simin Chen, Hongmei Zhang, Gongmin Zhang, Changwu Zheng, Hongxi Xu
Summary: This study aimed to differentiate mountain-cultivated ginseng by age using LC-MS analysis and machine learning models. The study successfully predicted the age group of ginseng samples based on identified biomarkers.
JOURNAL OF SEPARATION SCIENCE
(2023)
Article
Chemistry, Organic
Fan Wu, Zhiming Li, Chao Fu, Guan Wang, Changwu Zheng, Xiaoyu Wu
Summary: The asymmetric α-allylation of α-aryl-substituted 2-acetylimidazoles using Ni/Pd catalysts was successfully developed. The reaction involves the activation of the enolate of an acetyl imidazole by a nickel-bisoxazoline complex, followed by a reaction with a π-allylpalladium electrophile generated from an allyl alcohol derivative using a palladium-based catalyst. The broad substrate scope and the gram-scale reaction demonstrated the utility of this method.
Review
Biochemistry & Molecular Biology
Yee Lin Phang, Song Liu, Changwu Zheng, Hongxi Xu
Summary: Natural products containing a phloroglucinol motif have significant medicinal value and biological activities. Recent studies have focused on synthetic approaches to these compounds, which have been widely used in treatment and clinical trials.
NATURAL PRODUCT REPORTS
(2022)
Article
Chemistry, Organic
Xueying Wang, Phang Yee Lin, Changwu Zheng, Hongxi Xu
Summary: Xanthochymol, a PPAP natural compound, was synthesized from 3,3-dimethylglutaric acid in 11 steps with a total yield of 10%, providing references for future research on its side chain isomers.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Huaimo Wu, Song Liu, Youyi Wang, Man Yuan, Hong Zhang, Hua Zhou, Lianbo Xiao, Changwu Zheng, Hongxi Xu
Summary: A mild, efficient, and green method for the synthesis of 1,2-dihydroxanthones through Claisen condensation and O-cyclization has been developed in one pot with waste-induced relay catalysis. The by-product of the first step functions as a promoter for the second step, allowing the reaction to proceed efficiently in aqueous media without the need for additional catalysts. The versatility of DHXs is demonstrated by their conversion to various complex structures.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Liping Wang, Xueying Wang, Guocai Zhang, Wenwei Fu, Hong Zhang, Hua Zhou, Hongxi Xu, Changwu Zheng
Summary: A concise and stereoselective method has been developed for the synthesis of polycyclic polyprenylated acylphloroglucinols and analogues in both racemic and asymmetric fashions. This method has been successfully applied in the total synthesis of natural products with biological activities.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.
