Article
Chemistry, Organic
Chun-Ting He, Xiao-Li Han, Yan-Xue Zhang, Zhen-Ting Du, Chang-Mei Si, Bang-Guo Wei
Summary: An efficient method has been developed to access functionalized (2,3-dihydroisoxazol-4-yl) ketones by reacting nitrones with ynones or terminal ynones in a one-pot fashion, resulting in moderate to good yields.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Jie-Hui Zhang, Cheng-Lin Pan, Huan-Huan Zhang, Peng-Fei Xu, Yong-Chun Luo
Summary: A Sc(OTf)3 catalyzed [3 + 2]-annulation reaction has been developed for the conversion of donor-acceptor aziridines and exo-glycals into carbohydrate-spiro-heterocycles, yielding proline analogues and polycyclic compounds. This reaction also revealed the stereochemistry characteristic of the reaction between racemic D-A aziridines and chiral enolethers.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Jose Cortes Vazquez, Jacqkis Davis, Vladimir N. Nesterov, Hong Wang, Weiwei Luo
Summary: A formal [3 + 3] cyclization reaction has been developed for the synthesis of 1,3,4-oxadiazinanes with generally high yields (up to 96%). The reaction, catalyzed by Sc(OTf)(3), has a broad substrate scope for both diaziridines and quinones. The synergistic activation of 1,3-dipolar diaziridines and dipolar quinones was found to be essential for enabling this reaction.
Article
Chemistry, Organic
Kshitiz Verma, Manmath Mishra, Prabhat Kumar Maharana, Hemanga Bhattacharyya, Sharajit Saha, Tharmalingam Punniyamurthy
Summary: A Sc(III)-catalyzed domino C-C and C-N bond formation of N-sulfonyl aziridines with quinones has been achieved, leading to the synthesis of functionalized indolines at a moderate temperature. The key practical features of this study include the umpolung reactivity of aziridines, radical pathway, mild reaction conditions, substrate scope, and the coupling of drug molecules in a postsynthetic application.
Article
Chemistry, Organic
Xinyi Wan, Shan Wang, Chengjun Wu, Jianbo Gan, Cunde Wang
Summary: The synthesis of polysubstituted quinolines was investigated through a Yb(OTf)(3)-mediated annulation of cyclopropane-1,1-dicarbonitriles and 2-aminobenzaldehydes, resulting in generally good yields. The cascade reaction involves ring opening, intermolecular nucleophilic addition, intramolecular nucleophilic addition, and demalononitrile aromatization, with the malononitrile group acting as a removable directing group mediated by Yb(OTf)(3).
Article
Chemistry, Multidisciplinary
Peter-Yong Wang, Itai Massad, Ilan Marek
Summary: The facile and modular access to stereodefined disubstituted aldehyde-derived silyl enol ethers allowed for their successful application in a stereoselective aldol reaction, resulting in excellent yields and diastereomeric ratios. The counter-intuitive stereochemical behavior of this Mukaiyama-aldol reaction is explained by a non-classical open transition state.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jiang Nan, Guanjie Huang, Shilei Liu, Jing Wang, Yangmin Ma, Xinjun Luan
Summary: Herein, a new reorganization/cycloaddition between two imine units catalyzed by In(OTf)(3) Lewis acid is disclosed, which is different from the well-known [4 + 2] cycloaddition version through the Povarov reaction. Using this unprecedented imine chemistry, a collection of synthetically useful dihydroacridines has been synthesized. Remarkably, the obtained products result in a series of structurally novel and fine-tuneable acridinium photocatalysts, providing a heuristic paradigm for synthesis and efficiently facilitating several encouraging dihydrogen coupling reactions.
Article
Chemistry, Organic
Sabera Sultana, Peter Yuosef M. Rubio, Hari Datta Khanal, Yong Rok Lee
Summary: This study describes the Sc(OTf)(3)/BF3 center dot OEt2-catalyzed annulation of 3-formylchromones with functionalized alkenes, providing a direct synthetic route to 2-hydroxybenzophenones. The reaction exhibits excellent regio- and chemoselectivities, suitable for late-stage functionalization. Additionally, it proceeds via [3 + 3] and [4 + 2] cycloaddition processes, tolerating various functional groups found in natural terpenes and steroids.
Article
Chemistry, Multidisciplinary
Shanshan Liu, Xianying Zhou, Lin-Yu Jiao, Chao Li, Zheng Wang
Summary: A mild and catalyst-free sunlight induced protocol for the remote meta bromination of electron-deficient indoles is described for the first time. Herein, N-bromosaccharin is activated by sunlight irradiation. Alternately, a synergistic activation model (Sc(OTf)(3)/HFIP) has also been developed for the activation of haloniums, complementary to the light induced strategy. In addition, the cascade C6-H bromination and benzylic C-H oxidation under photocatalytic conditions was also discussed. High regio-and chem-selectivity, mild reaction conditions, and scalability demonstrate great potential of the developed methods in practical applications and further functionalization.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Yu-Qing Xiao, Miao-Miao Li, Zheng-Xin Zhou, Yu-Jie Li, Meng-Yue Cao, Xiao-Peng Liu, Hai-Hua Lu, Li Rao, Liang-Qiu Lu, Andre M. Beauchemin, Wen-Jing Xiao
Summary: This article describes a palladium-catalyzed highly diastereo- and enantioselective (3+2) cycloaddition reaction, which successfully synthesizes a variety of chiral five-membered heterocycles. The key to the success of this reaction is the remote stereoinduction through hydrogen bond, addressing the challenge of generating chiral quaternary stereocenters using substrates with two different acceptors.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Zhenjie Su, Shaozhong Wang
Summary: An atom-economical protocol utilizing Sc(OTf)3 as the catalyst has been developed to synthesize densely substituted 4acyl-2-quinolones. Mechanistic experimental studies suggest the involvement of coordinative interaction between Sc(OTf)3 and the substrate, formation of an oxetene intermediate, and an electrocyclic ring-opening of the oxetene.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Motohiro Yasui, Maki Inoue, Kotone Nakao, Norihiko Takeda, Masafumi Ueda
Summary: A Sc(OTf)(3)-catalyzed iodocyclization/Ritter-type amidation of N-alkoxypropiolamides has been developed for the synthesis of 4-iodoisoxazol-3(2H)-ones bearing an amide group. This domino protocol allows the construction of the valuable heterocycle isoxazol-3(2H)-one and the introduction of two functional groups. The reaction has a broad substrate scope, can be carried out on a large scale, and the N-alkoxy group in the substrate helps to suppress some side reactions.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Yingkun Yan, Min Li, Min Liu, Min Huang, Lianyi Cao, Wenzhe Li, Xiaomei Zhang
Summary: Isoxazolines are important for the development of synthetic methodology and pharmaceutics. In this study, a new method using Sc(OTf) catalyst for the dearomative [3 + 2] annulation of 5-aminoisoxazoles with quinone imine ketals (QIKs) and quinone monoacetals (QMAs) was reported. This method allows for the synthesis of fusion compounds of indolines and 2,3-dihydrobenzofurans with isoxazolines, with good yields and diastereoselectivities.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Zhuo-Ya Mao, Chen Wang, Xiao-Di Nie, Xiao-Li Han, Han-Qing Dong, Chang-Mei Si, Bang-Guo Wei
Summary: An effective approach to access dyadic 1,3-oxazinan-2-ones and 4,4a,5,6-tetrahydro-[1,3]oxazino [3,4-a]quinolin-1(3H)-ones was developed through Sc(OTf)(3)-catalyzed intramolecular cyclization, providing moderate yields with excellent diastereoselectivities. The Lewis acid-catalyzed process yielded 2,5-trans-products.
Article
Chemistry, Organic
Ali Wang, Peizhuo Lv, Yuanhong Liu
Summary: A five-membered N-O heterocycle, 4,5-dihydro-1,2,4-oxadiazole, is discovered to act as a single nitrogen atom transfer reagent through the elimination reaction of a ketone/aldehyde and a nitrile. This reagent is successfully used in the synthesis of isoxazoles from ynones promoted by Sc(OTf)(3) or through Au(I)/Sc(OTf)(3) synergistic catalysis. The efficiency of this protocol is also demonstrated by its application in modifying structurally complex natural products and pharmaceuticals.
