Article
Chemistry, Multidisciplinary
Lingpu Meng, Jingjie Yang, Mei Duan, You Wang, Shaolin Zhu
Summary: Regio- and enantioselective hydroarylamination, hydroalkylamination and hydroamidation of styrenes have been developed using NiH catalysis with a simple bioxazoline ligand under mild conditions. A variety of enantioenriched benzylic arylamines, alkylamines and amides can be easily accessed by employing nitroarenes, hydroxylamines and dioxazolones as amination reagents. Chiral induction in these reactions is proposed to proceed through an enantiodifferentiating syn-hydronickellation step.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Leipeng Xie, Jimin Liang, Haohao Bai, Xuanyu Liu, Xiao Meng, Yuan-Qing Xu, Zhong-Yan Cao, Chao Wang
Summary: In this paper, a ligand-controlled, directing-group-assisted strategy was reported to promote NiH-catalyzed site-selective hydroamination of unactivated alkenes. Proper bidentate nitrogen-containing ligands were used to achieve good-to-excellent regioselectivity for the synthesis of 1,1-, 1,2-, and 1,3-diamines from the same substrates. Various O-benzoylhydroxylamine electrophiles with different functional groups can be installed via Ni migration or nonmigration. These protocols provide a method for the enantioselective synthesis of valuable 1,2-diamines and 1,3-diamines.
Article
Chemistry, Organic
Yang Gao, Yushan Cui, Yanping Huo, Jinhong Chen, Minwei She, Xianwei Li, Qian Chen, Xiao-Qiang Hu
Summary: A nickel-catalyzed polarity-reversed hydroamination of olefins has been developed, providing a convenient route to N-alkyl-2-aminobenzophenones intermediates. This method is compatible with a wide range of olefins and anthranils, delivering the desired amines in high yields, making it applicable for organic synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Alla I. Vaskevych, Nataliia O. Savinchuk, Ruslan I. Vaskevych, Svitlana V. Shishkina, Mykhailo V. Vovk
Summary: 2-butenylquinazolin-4(3H)-ones can undergo intramolecular aza-Wacker cyclization to form methylene-substituted pyrrolo(pyrido)[2,1-b]quinazolinones when treated with the catalytic system Pd(OAc)(2)/PPh3/Cs2CO3/benzoquinone in dioxane or Pd(PPh3)(2)Cl-2/t-BuONa/Cs2CO3/benzoquinone in toluene. The latter catalytic system also reacts with pentenyl(hexenyl)quinazolin-4(3H)-ones, but leads to the formation of vinyl-substituted pyrrolo(pyrido)[2,1-b]quinazolinones via competition between aminopalladation of C-H multiple bonds and allylic C(sp(3))-H bond activation.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Hong Jiang, Xiangxiang Zhao, Wenqiang Zhang, Yan Liu, Haiyang Li, Yong Cui
Summary: Chiral imidodiphosphates (IDPs) have been used as strong Bronsted acid catalysts, but their dynamic transformation often leads to low enantioselectivity. In this study, the topologies of metal-organic frameworks (MOFs) were utilized to control IDP conformations and local chiral microenvironments for efficient enantioselective catalysis. Two different porous Dy-MOFs were obtained from an enantiopure 1,1’-biphenol IDP-based tetracarboxylate ligand, and all IDPs were rigidified to a single O,O-syn conformation with enhanced Bronsted acidity. The more compact 4-connected IDP-based MOF exhibited high enantioselectivity in the challenging O,O-acetalization reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Yuting Qiu, Haiyan Yuan, Xiaoying Zhang, Jingping Zhang
Summary: Computational studies of CPA-catalyzed DyKAH reactions reveal a catalytic asymmetric model involving pi-allylic carbocationic intermediates, with high E/Z selectivity achieved through intermolecular proton transfer. Noncovalent interactions within the electrostatic environment created by the phosphoric acid are key to explaining the enantioselectivity, while the chiral SPINOL scaffolds control the signs of enantioselectivity through substrate binding pocket configurations. Overall, understanding these mechanisms is crucial for guiding DyKAH reactions.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
P. Veeraraghavan Ramachandran, Shivani Choudhary
Summary: Monotrifluoroacetoxyborane-amines are efficient reagents for the one-pot, tandem reductive amination/alkylation-cycloamidation of keto or amino acids to achieve the synthesis of 5-aryl or 5-methyl pyrrolidin-2-ones and 6-aryl or 6-methyl piperidin-2-ones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Ryukichi Takagi, Duyen Thi Duong
Summary: This study used density functional theory calculations to investigate the mechanism of enantioselective intramolecular hydroamination catalyzed by chiral binaphthol N-triflylphosphoramide (NPTA). It reveals the details of the hydrogen bonding mode between NPTA and the substrate, emphasizing the importance of the dual hydrogen binding properties of the thiourea moiety for the reactivity and stereoselectivity of the hydroamination.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Liam A. McLean, Matthew W. Ashford, James W. B. Fyfe, Alexandra M. Z. Slawin, Andrew G. Leach, Allan J. B. Watson
Summary: We have reported a method for synthesizing chiral vicinal chloroamines through asymmetric protonation using chiral Bronsted acids. The process is highly selective and the origins of asymmetry and the effects of catalyst substitutions have been clarified by DFT calculations. Additionally, we have demonstrated the utility of this method in synthesizing a wide range of heterocycle-substituted aziridines and vicinal diamines.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Dandan Yang, Hai Huang, He Zhang, Li-Ming Yin, Mao-Ping Song, Jun-Long Niu
Summary: The study achieved the Co-H-catalyzed intermolecular hydroamination of unactivated alkenes with various amine electrophiles by introducing a removable directing group. The catalytic system showed substrate-dependent regioselectivity, broad substrate scope, and simplified reaction conditions, providing a general and flexible protocol for the preparation of various amino acid derivatives.
Article
Chemistry, Multidisciplinary
Xiao-Si Hu, Jun-Xiong He, Ying Zhang, Jian Zhou, Jin-Sheng Yu
Summary: The study presents a transition metal-free highly stereoselective positional isomerization strategy using Al(OTf)(3) as a catalyst to synthesize acyclic alkenes with high stereoselectivity. Mechanistic studies reveal the formation of a carbocation intermediate with Al(OTf)(3) acting as a hidden Brønsted acid catalyst.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Review
Chemistry, Organic
Shuhui Li, Xiaoxuan Li, Hui Yao, Mengting Tan, Dan Xu, Nianyu Huang, Nengzhong Wang
Summary: Straight-chain omega-amino-alpha, beta-unsaturated carbonyl compounds are versatile organic synthons with important applications in organocatalysis. This review discusses the recent applications of these synthons in covalent catalysis, non-covalent catalysis, and bifunctional catalysis.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Yu-Jun Bai, Xue-Ying Wang, Si-Kai Zhu, Xiao-Hui Zheng, Sheng-Yong Zhang, Ping-An Wang
Summary: A highly chiral cyclopropenimine-catalyzed enantioselective Michael addition between benzophenone-imine of glycine esters and beta-substituted alpha,beta-unsaturated pyrazolamides has been realized to afford Michael adducts in up to 95% yield and 99% ee.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Faju Li, Linhong Long, Yan-Mei He, Zeyu Li, Hui Chen, Qing-Hua Fan
Summary: A unique family of chiral macrocyclic ligands with a tunable saddle-shaped cavity is described. Using their manganese(I) complexes, the first example of earth-abundant transition metal-catalyzed asymmetric formal anti-Markovnikov hydroamination of allylic alcohols was achieved, providing a practical access to synthetically important chiral gamma-amino alcohols. The study revealed the remarkable role of the macrocyclic framework in the reaction process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Mandapati Bhargava Reddy, Sakthivel Prabhu, Ramasamy Anandhan
Summary: An unprecedented reductive hydroamidative/hydroquinazolinative cascade cyclization of o-alkynylated derivatives was achieved via proton-coupled electron transfer (PCET) under electrolysis. In a single step, the rapid assembly of isoindolinones and novel isoindole-fused quinazolinones were achieved through electrolysis by the hydroamidation of amidyl/quinazolinone aminyl radicals with C-C triple bond addition via 5-exo-dig cyclization followed by olefinic reduction without external reductants. Control and cyclic voltammetry experiments support a mechanistic explanation of the electrochemical cascade, and these experiments indicate that the electrolyte is the source of hydrogen for the olefin reduction.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Zhe Wang, Jiang-Tao Cheng, Zhichao Shi, Na Wang, Feng Zhan, Sheng-Peng Jiang, Jin-Shun Lin, Yuyang Jiang, Xin-Yuan Liu
Summary: This study reported a first catalytic enantioselective intermolecular radical aminotrifluoromethylation of alkene with hydrazine and Togni's reagent by Cu(I)/CPA cooperative catalysis, accessing enantioenriched diarylmethylamines. The highly asymmetric induction of C-N bond formation was achieved by using a CPA catalystviahydrogen-bonding and ion pair interaction, leading to high enantioselectivity and excellent chemoselectivity.
Article
Chemistry, Applied
Zhichao Shi, Tingting Fan, Xun Zhang, Feng Zhan, Zhe Wang, Lei Zhao, Jin-Shun Lin, Yuyang Jiang
Summary: A Y(OTf)(3)-catalyzed reaction has been developed for the efficient synthesis of imidazolidines, which show promising anti-tumor activity against various human cancer cell lines. Mechanistic investigations suggest these imidazolidines are formed through an S(N)1-like pathway.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Feng Zhan, Zhe Wang, Guan-Zheng Wu, Zhichao Shi, Xun Zhang, Qinglu Zuo, Jin-Shun Lin, Yuyang Jiang
Summary: A TfOH-catalyzed [3+2] cycloaddition of donor-acceptor oxiranes with isothiocyanates was developed, allowing for the synthesis of highly substituted 1,3-oxathiolane-2-imines with high yields, Z-selectivity, and excellent functional group tolerance. The reaction protocol can be easily scaled up to gram level and the cycloadduct can be transformed into 1,3-oxathiolane-2-one through acid hydrolysis with moderate yield.
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
Na Wang, Li-Wen Fan, Jin Zhang, Qiang-Shuai Gu, Jin-Shun Lin, Guo-Qiang Chen, Xin-Yuan Liu, Peiyuan Yu
Summary: This study investigates the highly enantioselective intramolecular hydroamination reaction and uncovers its uncommon reaction mechanism. The reactivity of this reaction is primarily determined by the substituents on the internal carbon of the alkene, as well as the substituents on the terminal alkene carbons. The lower acidity of chiral phosphoric acids compared to chiral NTPAs results in a slower reaction.
ORGANIC CHEMISTRY FRONTIERS
(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)