Article
Chemistry, Multidisciplinary
Qing-Yun Fang, Jie Han, Mingzhe Qin, Weipeng Li, Chengjian Zhu, Jin Xie
Summary: Reported here is a three-component 1,2-difunctionalization reaction of alkenes, unactivated alkyl bromides, and nucleophiles (e.g., amines and indoles) using a trinuclear gold catalyst [Au-3(tppm)(2)](OTf)(3). This reaction enables facile 1,2-aminoalkylation and 1,2-alkylarylation and exhibits a broad reaction scope and excellent functional group compatibility (>100 examples with up to 96% yield). It also provides a robust formal [2+2+1] cyclization strategy for the concise construction of pyrrolidine skeletons under mild reaction conditions. Mechanistic studies support an inner-sphere single electron transfer pathway for the successful cleavage of inert C-Br bonds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Huangbin Sun, Guofang Jiang
Summary: We have developed a transition-metal-free radical approach for the functionalization of unactivated alkenes, providing access to a variety of synthetically important α-functionalized alkynyl ketones. This approach simultaneously installs carbonyl, alkynyl, and other functional groups into the alkenes, demonstrating excellent functional group compatibility and selectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Liang Zeng, Jing-Hao Qin, Gui-Fen Lv, Ming Hu, Qing Sun, Xuan-Hui Ouyang, De-Liang He, Jin-Heng Li
Summary: Here, the authors report a new electrophotocatalytic intermolecular reductive 1,2-diarylation of alkenes using aryl halides and cyanoaromatics. The reaction demonstrates a broad substrate scope, excellent functional group compatibility, and excellent selectivity. Mechanistic investigations suggest a radical process initiated by the reductive generation of aryl radicals from aryl halides and terminated by radical-radical coupling with cyanoaromatic radical anions.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Organic
Yufei Li, Xin Liang, Kaikai Niu, Jun Gu, Fang Liu, Qing Xia, Qingmin Wang, Weihua Zhang
Summary: An attractive, versatile, and operationally simple visible-light-induced trifluoromethylation method has been demonstrated, which is transition-metal-free, photocatalyst-free, and oxidant-free. Inexpensive and readily available triflic anhydride (Tf2O) was chosen as the radical trifluoromethyl source, and thianthrene was used as a recyclable Tf2O-activating reagent, achieving a high-yielding and scalable trifluoromethylation reaction. Density functional theory and mechanistic studies revealed that the reaction involves a free radical homolytic process excited by visible light, generating a key trifluoromethyl radical intermediate.
Article
Chemistry, Multidisciplinary
K. Keerthika, S. Bazil Muhammed, K. Geetharani
Summary: We describe a protocol for synthesizing trifluoromethylated alkyl boronates from alkenes using the mutual activation of Togni II and bis(catecholato)diboron reagents without the need for a catalyst or additives. This method enables the regioselective synthesis of trifluoromethylated alkyl boronates from unactivated alkenes, including natural products and drug derivatives. The boronic esters in the product can be further used to access a range of trifluoromethyl containing compounds. The reaction mechanism involves the formation of trifluoromethyl and boron centered radicals, with the more Lewis acidic diboron reagent driving the rapid radical formation.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Biochemistry & Molecular Biology
Xiaoming Ma, Qiang Zhang, Wei Zhang
Summary: Radical transformations are powerful tools in organic synthesis for constructing molecular scaffolds and introducing functional groups. Radical difunctionalization reactions allow radicals to be relocated through resonance, hydrogen transfer, and ring opening, enabling the synthesis of 1,3-, 1,4-, 1,5-, 1,6-, and 1,7-difunctionalization products. These reactions offer synthetic efficiency, operational simplicity, and product diversity, making them advantageous for remote difunctionalization.
Article
Chemistry, Organic
Shan-Shan Li, Yu-Shi Jiang, Li-Ning Chen, Dan-Na Chen, Xue-Ling Luo, Cheng-Xue Pan, Peng-Ju Xia
Summary: A study reports the 1,2-iminylalkylation of diazenes using alkyl iodides in combination with an O-benzoyl oxime. The O-benzoyl oxime acts as a radical precursor and XAT mediator in this transformation. It is found that besides common alkyl iodides, other alkyl iodides can also serve as C-radical precursors in the 1,2-iminylalkylation with electrophilic diazenes as radical acceptors, including iodomethane, iodomethane-d 3, trifluoroiodomethane, ethyl difluoroiodoacetate, and iodoalkanes containing unprotected hydroxyl and amide groups.
Article
Chemistry, Organic
Yi Lu, Zhirui Liu, Chao Liu, Yunpeng Wu, Lu Li, Siyuan Liu, Hong Wang, Wei Gao, Zhenxian Liu, Jianbin Chen
Summary: An environmentally friendly electrochemical fluorotrifluoromethylation of styrenes was developed, which involves tandem processes of electro-oxidation and radical and nucleophilic addition. Using commercial CF3SO2Na and Et3N•3HF as the sources of CF3 and F, a range of potentially bio-active multi-site F-containing compounds were obtained in moderate to good yields. This catalyst- and oxidant-free fluorotrifluoromethylation strategy offers mild conditions and high step economy features, and the reaction mechanism was investigated using several analytical methods.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Attila M. Remete, Melinda Nonn, Balazs Volk, Lorand Kiss
Summary: Due to the relevance of fluorine-containing organic molecules in drug research, the synthesis of organofluorine scaffolds is highly significant in synthetic organic chemistry. Trifluoromethylative difunctionalizations of carbon-carbon multiple bonds, with the introduction of a CF3 group and another function, have great potential. Alkynyltrifluoromethylation reactions, especially, are gaining interest in synthetic chemistry. This review summarizes recent developments in alkynyltrifluoromethylation reactions, including reactions involving intramolecular alkynyl migration and intermolecular transformation, as well as reactions of alkynes.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Multidisciplinary
Xinrui Dong, Wenhua Jiang, Dexiang Hua, Xiaohui Wang, Liang Xu, Xiaoxing Wu
Summary: The addition of trifluoromethyl sulfonyl radicals to alkynes is a valuable method for constructing highly functionalized sulfonyl compounds. This process shows broad functional group compatibility and potential in drug discovery and chemical biology.
Article
Chemistry, Organic
Yulei Zhao, Xuqiang Guo, Shuai Li, Yuhang Fan, Xuejun Sun, Laijin Tian
Summary: A PhB(OH)(2)-promoted electrochemical sulfuration-formyloxylation reaction has been reported for the synthesis of various sulfur compounds, eliminating the need for metal catalysts and external chemical oxidants. This strategy allows for the facile preparation of beta-hydroxy sulfides, beta-formyloxy sulfoxides, beta-formyloxy sulfones, and (E)-vinyl sulfoxides.
Article
Chemistry, Organic
Xue-Ling Luo, Shan-Shan Li, Yu-Shi Jiang, Fu Liu, Shu-Hui Li, Peng-Ju Xia
Summary: A new class of iminosulfonylation reagents was developed for the 1,2-iminosulfonylation of various olefins. Olefins containing bioactive molecules produced the desired iminosulfonylation products in synthetically useful yields. The first remote 1,6-iminosulfonylation of alkenes was achieved using oxime ester bifunctionalization reagents, resulting in the synthesis of more than 40 structurally diverse beta-imine sulfones in moderate to excellent yields.
Article
Chemistry, Multidisciplinary
Fangming Chen, Lvqi Jiang, Chunyang Hu, Jie Liu, Wenbin Yi
Summary: This study reports an unprecedented usage of CF3SO2Na as a radical trifluoromethylthiolation reagent. A photocatalyzed ditrifluoromethylthiolation reaction of alkenes with CF3SO2Na in the presence of PPh(3 )and catalytic copper has been developed. Mechanistic studies reveal two different photocatalytic quenching mechanisms.
SCIENCE CHINA-CHEMISTRY
(2023)
Review
Chemistry, Organic
Jin-Yang Chen, Jing Huang, Kai Sun, Wei-Min He
Summary: This review discusses key activation methods for Togni's reagents under transition-metal-free conditions, showcasing related research areas and mechanisms to stimulate interest in participating in the development of novel efficient transition-metal-free trifluoromethylations using Togni's reagents.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Tavinder Singh, Seshadri Reddy Nasireddy, Ganesh Chandra Upreti, Shivani Arora, Anand Singh
Summary: A visible-light-mediated, haloalkyl-radical-initiated, three-component olefin difunctionalization is described. The use of haloalkyl radicals generated through halogen atom abstraction by α-aminoalkyl radicals has been demonstrated to access new halogenated chemical space. Overall, the alkylcarbofunctionalization of styrenes was achieved by using them as (poly)haloalkyl radical acceptors and subsequent C-C bond formation with quinoxalinones.
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
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)
Article
Chemistry, Organic
Jiao Hu, Shengyu Li, Xiaolin Wang, Sheng-Cai Zheng, Xiaoming Zhao
SYNTHESIS-STUTTGART
(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
Biochemistry & Molecular Biology
Xiao-Lin Wang, Ji-Teng Chen, Sheng-Cai Zheng, Xiao-Ming Zhao
Summary: The utilization of 6,6-dimethyl-3-((trimethylsilyl)oxy)cyclohex-2-en-1-one, derived from an unsymmetrical 4,4-dimethylcyclohexane-1,3-dione, in iridium-catalyzed allylic enolization is achieved under mild conditions. The presence of a quaternary carbon and adjustment of reaction conditions enable high selectivities in terms of chemoselectivity, regioselectivity, and enantioselectivity. This method provides substituted 2-(but-3-en-2-yl)-3-hydroxy-6,6-dimethylcyclohex-2-en-1-ones in good to high yields with excellent chemo-, regio-, and enantioselectivities. Additionally, the formation of chiral carbon-fluorine bonds is induced by an adjacent chiral carbon center.
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)
