Article
Chemistry, Applied
Andrea Guerrero-Corella, Miguel A. Valle-Amores, Alberto Fraile, Jose Aleman
Summary: An asymmetric organocatalytic aza-Michael addition reaction of ketimines to nitroolefins is described, utilizing 2-hydroxybenzophenone imine to improve the enantioselective addition of N-centered nucleophiles to nitroalkenes. The versatility of the process is demonstrated under both batch and flow conditions, resulting in the synthesis of a wide variety of nitroamine derivatives with excellent yields and enantioselectivities. Additionally, this methodology was successfully applied to the formal synthesis of VNI, a drug-like scaffold for the treatment of Chagas disease.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Review
Biochemistry & Molecular Biology
Jianlin Han, Jorge Escorihuela, Santos Fustero, Aitor Landa, Vadim A. Soloshonok, Alexander Sorochinsky
Summary: This review critically discusses the literature data on the preparation of substituted GABA derivatives using the Michael addition reaction. Special attention is paid to asymmetric methods featuring synthetically useful stereochemical outcomes and operational simplicity.
Article
Chemistry, Multidisciplinary
Yong-Sin Chen, Ming-Hsuan Huang, Yan-Peng Cheng, Duen-Ren Hou
Summary: In this study, chiral N-substituted 4-pyrimidinones were prepared for the first time through an enantioselective, organocatalytic aza-Michael addition reaction. The optimization of solvents, catalysts, and acceptors resulted in high yields and enantioselectivities.
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Estelle Silm, Ivar Jarving, Tonis Kanger
Summary: An asymmetric Michael reaction between cyclopentane-1,2-dione and alkylidene oxindole was studied using a multifunctional squaramide catalyst, resulting in high enantioselectivities and moderate diastereoselectivities of the Michael adducts.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Laura A. Bryant, Kenneth Shankland, Hannah E. Straker, Callum D. Johnston, Nicholas R. Lees, Alexander J. A. Cobb
Summary: The article describes a rare organocatalytic intramolecular cyclization of resorcinols with a high enantioselectivity using a specific organocatalyst. The obtained bicyclic resorcinols show excellent utility in the synthesis of cannabinoid-like compounds, and exhibit anticonvulsant activity.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Jen-Yu Kuan, I-Ting Chen, Hsuan Lin, Jeng-Liang Han
Summary: We have developed a substrate-dependent, regio- and stereocontrolled diversity-oriented organocatalytic vinylogous Michael addition/cyclization cascade of 2-alkylidene indane-1,3-diones with enals, using secondary amines as the catalyst. This method allows for the selective synthesis of spiroindane-1,3-diones, tetrahydrofluoren-9-one derivatives, and benzofused oxabicyclo[3.3.1]nonanes. Plausible catalytic pathways have been proposed, and DFT calculations have clarified the mechanisms involved.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Qijian Ni, Zhiming Zhu, Yanjun Fan, Xiaoyun Chen, Xiaoxiao Song
Summary: The research has successfully developed an organocatalytic highly diastero- and enantioselective Friedel-Crafts conjugate addition method for adding indolizines to cyclopentenediones to obtain the desired products. The utility of the method was demonstrated through various late-stage functionalizations.
Article
Chemistry, Multidisciplinary
Rakesh K. Saunthwal, Maria Schwarz, Rajendra K. Mallick, William Terry-Wright, Jonathan Clayden
Summary: A practical method for enantioselective synthesis of alpha,alpha-diarylmethylamines without using transition metals is achieved through asymmetric alpha-arylation of benzylamines. Enantioselective lithiation of N '-aryl-N-benzyl-N-isopropyl ureas using a chiral lithium amide base generates benzyllithium, which undergoes a stereospecific intramolecular nucleophilic aromatic substitution to form the urea derivative of alpha,alpha-diarylmethylamine with ee up to >99%. Acid treatment induces an azatropic shift with retention of configuration, allowing hydrolysis to yield the target amine.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Irma Garcia-Monzon, Jorge Borges-Gonzalez, Tomas Martin
Summary: The heterogenization of homogeneous catalysts onto a solid support is a crucial step towards sustainable chemistry. In this study, we developed a series of polymer-supported tetrahydropyran-based hybrid dipeptides as active catalysts for the enantioselective Michael addition of aldehydes to beta-nitrostyrenes. The optimal anchor position and orientation between the catalyst and solid support, as well as the linker length, were carefully designed to enhance the catalytic efficiency. These supported catalysts exhibited high yields and enantiomeric excesses, and detailed deactivation studies provided important insights for prolonging their useful life.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Shi-Jie Zhu, Zhi-Feng Hao, Ya Pan, Ying Zhou, Xiong-Li Liu, Ming Zhang, Chuan-Wen Lei
Summary: In this study, a stepwise enantioselective formal (3 + 2) cyclocondensation reaction was successfully accomplished, leading to the synthesis of spiro-fused pentacyclic spirooxindoles. The reaction showed good overall yields, excellent dr, and high ee values.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Shi-Jie Zhu, Zhi-Feng Hao, Ya Pan, Ying Zhou, Xiong-Li Liu, Ming Zhang, Chuan-Wen Lei
Summary: The first enantioselective formal (3 + 2) cyclocondensation involving alpha,fi-unsaturated pyrazoleamides as 3-carbon partners was successfully achieved in a stepwise fashion. The protocol led to the synthesis of spiro-fused pentacyclic spirooxindoles with good overall yields, excellent diastereomeric ratios, and high enantiomeric excess values.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Eugenia Marques-Lopez, Isaac G. Sonsona, Miryam Garces-Marin, M. Concepcion Gimeno, Raquel P. Herrera
Summary: In this study, the potential of phosphites as nucleophiles for the asymmetric synthesis of chiral chromene derivatives was explored. By employing asymmetric organocatalyzed phospha-Michael addition, chiral chromenylphosphonates were synthesized using a bifunctional squaramide. The optimized protocol provided good reactivity with yields of up to 95% and chiral products with an enantiomeric excess of up to 98%.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Xin-Xing Wu, Hao Ye, Ming Li, Jianing Qian, Hong Dai, Yujun Shi
Summary: A formal [6 + 1] annulation reaction has been developed through sequential Michael addition/palladium-catalyzed alpha-arylation of ketones, providing an efficient route to diverse acylated caprolactams through double C-C bond formation of the same site from methyl ketones. The reaction features broad substrate scope, good functional group tolerance, easy scale-up, and useful transformations of the products.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Daniel Rozsar, Alistair J. M. Farley, Iain McLauchlan, Benjamin D. A. Shennan, Ken Yamazaki, Darren J. Dixon
Summary: This article describes the enantioselective intermolecular conjugate addition of nitroalkanes to unactivated alpha,beta-unsaturated esters catalyzed by a bifunctional iminophosphorane (BIMP) superbase. It provides a straightforward approach to the synthesis of pharmaceutically relevant enantioenriched gamma-nitroesters with unprecedented selectivity. The methodology demonstrates broad substrate scope and has been successfully applied on a gram scale with reduced catalyst loading, allowing for catalyst recovery.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Dae Young Kim
Summary: A one-pot strategy has been developed for the synthesis of multisubstituted 3,4-dihydrocoumarins with high yields and excellent diastereoselectivity. This approach involves C-H oxidation and cyclization cascade reactions of 2-alkyl phenols and oxazolones in the presence of silver oxide and p-toluenesulfonic acid as catalysts.
Review
Chemistry, Multidisciplinary
Jun Kee Cheng, Shao-Hua Xiang, Shaoyu Li, Liu Ye, Bin Tan
Summary: Atropisomerism is a stereochemical behavior exhibited by three-dimensional molecules with rotationally restricted sigma bonds, and compounds with atropisomerically chiral properties are increasingly utilized in fields where molecular asymmetry is influential. There is a steady demand for atroposelective synthesis, leading to conceptually novel and streamlined methods for expanding the structural diversity of atropisomers. This review summarizes key achievements in the stereoselective preparation of biaryl, heterobiaryl, and nonbiaryl atropisomers between 2015 and 2020, emphasizing synthetic strategies for each structural class and potential applications of atropochiral targets.
Article
Chemistry, Multidisciplinary
Jian Zhang, Jun Wei, Wei-Yi Ding, Shaoyu Li, Shao-Hua Xiang, Bin Tan
Summary: Pnictogen-bonding catalysis based on sigma-hole interactions has been the focus of attention for synthetic chemists. A novel chiral antimony cation/anion pair was utilized to catalyze the enantioselective transfer hydrogenation of benzoxazines with remarkable efficiency and enantiocontrol potency even at 0.05 mol % loading. Investigation into the properties of the catalyst and mechanistic insights were conducted through nonlinear effect studies, 1H NMR, LC-MS, and control experiments.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Jian-Hui Mao, Yong-Bin Wang, Limin Yang, Shao-Hua Xiang, Quan-Hao Wu, Yuan Cui, Qian Lu, Jie Lv, Shaoyu Li, Bin Tan
Summary: The study developed an organocatalyst-controlled para-selective arene C-H functionalization strategy, addressing a persistent challenge in arene functionalization chemistry. By emulating enzyme catalysis, the chiral phosphoric acid catalyst provides an ideal chiral environment for stereoinduction, while the projecting substituents control the chemoselectivity and site-selectivity.
Article
Chemistry, Physical
San Wu, Shao-Hua Xiang, Shaoyu Li, Wei-Yi Ding, Lei Zhang, Peng-Ying Jiang, Zi-An Zhou, Bin Tan
Summary: This study addresses the lack of robust catalytic methods for stereoselective dihalogenation in organic synthesis, providing a novel strategy using urea directing moiety on alkenes. The approach allows for streamlined access to diverse dihalogenation products with exquisite stereo- and regiocontrol, demonstrating the potential for broad applications in the synthesis of complex molecules.
Article
Chemistry, Multidisciplinary
Wang Xia, Zi-An Zhou, Jie Lv, Shao-Hua Xiang, Yong-Bin Wang, Bin Tan
Summary: A new organocatalytic approach was developed for the synthesis of N-naphthyl phenothiazine and phenoxazine scaffolds through azo-group enabled C-H amination of arenes. This reaction showcased operational simplicity, substrate generality, and excellent functional group compatibility, with the catalyst efficiency preserved after 5 catalytic cycles.
CHEMICAL COMMUNICATIONS
(2022)
Review
Chemistry, Multidisciplinary
Jun Kee Cheng, Shao-Hua Xiang, Bin Tan
Summary: This paper describes the strategies to address the challenges in efficient synthetic access and skeletal variety within the organocatalytic context. The approaches include modulating nucleophilicity, designing electron-withdrawing activating groups, and using electrophilic arene precursors for arylation. These strategies have led to the synthesis of structurally diverse axially chiral compounds.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Shi-Jiang He, Shuai Zhu, Sheng-Qi Qiu, Wei-Yi Ding, Jun Kee Cheng, Shao-Hua Xiang, Bin Tan
Summary: This study discovered a novel type of axially chiral anthrone-derived skeleton by introducing axial chirality on symmetric anthrone skeletons through stereoselective condensation. The enantioenriched anthrones could be further transformed into dibenzo-fused seven-membered N-heterocycles with well-defined stereogenic center via Beckmann rearrangement.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Pengquan Chen, Mei-Jun Lv, Jun Kee Cheng, Shao-Hua Xiang, Xiang-Zhong Ren, Junmin Zhang, Bin Tan
Summary: Azonaphthalenes have been confirmed as effective arylation reagents for various asymmetric transformations. In this study, a highly efficient approach to form triaryl-substituted all-carbon quaternary stereocenters through chiral phosphoric acid-catalyzed enantioselective arylation of 3-aryl-2-oxindoles with azonaphthalenes is revealed. This chemistry is scalable and demonstrates excellent functional group tolerance, providing a series of 3,3-disubstituted 2-oxindole derivatives in good yields with excellent enantiocontrol.
Article
Chemistry, Multidisciplinary
Peng-Ying Jiang, San Wu, Guan-Jun Wang, Shao-Hua Xiang, Bin Tan
Summary: QUINAPs have been widely used in enantioselective transformations, but their limited substrate range and high cost hinder their broader application. In this study, we report the first atroposelective oxidation of an N atom using a chiral ketone catalyst, allowing the kinetic resolution of QUINAPOs with excellent enantioselectivity. The enantioenriched products can be easily converted into the desired QUINAP targets without loss of stereochemical integrity. Mechanistic investigations reveal the involvement of a dioxirane as the active catalytic species.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Ming Wu, Yi-Wei Chen, Qian Lu, Yong-Bin Wang, Jun Kee Cheng, Peiyuan Yu, Bin Tan
Summary: A highly efficient method for the synthesis of atropisomers through functionalization of the Si-C bond between dinaphthosiloles and silanol nucleophiles was presented. The versatile nature of the Si-C bond allows for the facile derivatization of chiral products into other functional atropisomers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Si-Li Lin, Ye-Hui Chen, Huan-Huan Liu, Shao-Hua Xiang, Bin Tan
Summary: In this study, chiral cyclobutene units were synthesized using bicyclo[1.1.0]butanes for the first time, offering an efficient and asymmetric route with good regio- and enantiocontrol. Control experiments verified the formation of a key carbocation intermediate at the benzylic position.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Ye-Hui Chen, Meng Duan, Si-Li Lin, Yu-Wei Liu, Jun Kee Cheng, Shao-Hua Xiang, Peiyuan Yu, Kendall N. Houk, Bin Tan
Summary: This article introduces an effective strategy for umpolung functionalization of imines through aromatization. The attachment of strongly electron-withdrawing groups to imines enhances their reactivity, enabling direct amination of (hetero)arenes. Additionally, the use of chiral catalysts allows for the synthesis of (hetero)aryl C-N atropisomers or enantioenriched aliphatic amines.
Article
Chemistry, Multidisciplinary
Peng-Ying Jiang, San Wu, Guan-Jun Wang, Shao-Hua Xiang, Bin Tan
Summary: QUINAPs are a crucial class of chiral compounds that have remarkable features in stereoinduction. However, their restricted substrate range and expensive price limit their broader utilization. In this study, the first atroposelective oxidation of an N atom using a chiral ketone catalyst was described, allowing the kinetic resolution of QUINAPOs with excellent enantioselectivity. Mechanistic investigations revealed the role of a dioxirane as the active catalytic species. The developed protocol has practicality and can be applied in enantioselective transformations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Ming Wu, Yi-Wei Chen, Qian Lu, Yong-Bin Wang, Jun Kee Cheng, Peiyuan Yu, Bin Tan
Summary: Chiral organosilanes are important chemical entities in the development of functional organic materials, asymmetric catalysis, and medicinal chemistry. An efficient method for atroposelective synthesis of biaryl siloxane atropisomers via organocatalytic Si-C bond functionalization of dinaphthosiloles with silanol nucleophiles is presented. The reaction proceeds through an asymmetric protonation and simultaneous Si-C bond cleavage/silanolysis sequence in the presence of a newly developed chiral Bronsted acid catalyst. The versatile nature of the Si-C bond expands the applicability of this method.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Heng-Hui Li, Shaoyu Li, Jun Kee Cheng, Shao-Hua Xiang, Bin Tan
Summary: An efficient photocatalytic system for obtaining functionalized N-heterobiaryls under mild conditions is described, suitable for gram-scale synthesis. The method demonstrates practicality and accessibility using commercially available starting materials.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)
