Article
Chemistry, Organic
Braj Gopal, Prasoon Raj Singh, Madan Kumar, Avijit Goswami
Summary: A new methodology for the synthesis of N-haloindole-fused dihydrothiopyrano derivatives has been developed via (3 + 3) -annulation of donor-acceptor cyclopropanes with indoline-2-thiones in the presence of Sc(OTf)3 as a Lewis acid catalyst. This protocol provides a variety of indole-fused dihydrothiopyrano molecules in good to excellent yields, which resemble other indole-fused tricyclic molecules with potential medicinal value. Additionally, a detailed reaction mechanism and transformation of the product into N-fused thiazino indole molecule have been described.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Tsukasa Tawatari, Ritsuki Kato, Riku Kudo, Kiyosei Takasu, Hiroshi Takikawa
Summary: In this study, we report on the intramolecular (3+2) cycloaddition reactions between ynamides and benzyne. These reactions involve the formation of two bonds and are facilitated by using benzyne precursors containing a chlorosilyl group. The intermediate indolium ylide in these reactions exhibits both nucleophilic and electrophilic properties at its C2 atom.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Tao Wang, Bo Huang, You-Qing Wang
Summary: Using chiral phosphoric acids as organocatalysts, a formal asymmetric (4+2) cycloaddition of 3-methylene isoindolinone and in situ-generated ortho-quinone methide substrates is achieved. This reaction allows the construction of spiro chroman-isoindolinones containing spiro-N,O-heterocycles with high enantioselectivity, with a broad substrate scope.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Lihua Xie, Yi Li, Shunxi Dong, Xiaoming Feng, Xiaohua Liu
Summary: The study demonstrates that the chiral amide-guanidine-catalyzed reaction can achieve the synthesis of chiral indolin-3-one derivatives with two contiguous tetrasubstituted stereocenters, yielding moderate to good results with high diastereoselectivities and enantioselectivities. A possible working mode was proposed to explain the chiral control of the process.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Mohammed Anif Pasha, Swamy Peraka, Dhevalapally B. Ramachary
Summary: By utilizing a quinine-thiourea-catalyzed sequential reaction, Lawsone aldehydes were transformed into chiral methanobenzo[f]azulenes/methanodibenzo[a,d][7]annulenes with high diastereomeric ratio and enantiomeric excess. This approach is valuable for the synthesis of important antibiotics due to the nature of the final molecules.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Durga Prasad Hari, Guillaume Pisella, Matthew D. Wodrich, Artem Tsymbal, Farzaneh Fadaei Tirani, Rosario Scopelliti, Jerome Waser
Summary: A new oxyalkynylation/cycloaddition reaction has been reported to synthesize complex polycyclic structures under mild conditions, with high efficiency and atom economy. The obtained products can be applied as chiral ligands for metal catalysis, providing a new method for organic synthesis. Computational studies provided a first rationalization of the low activation energy for the cycloaddition reaction based on counter-intuitive favorable dispersive interactions in the transition state.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Michael P. Doyle, Ming Bao
Summary: This study achieved a highly enantioselective synthesis of substituted pyrrolidines and 1,2-oxazinanes via stereoretentive [3 + 2]/[3 + 3]-cycloaddition of nonracemic donor-acceptor cyclopropanes with imines, triazines, and nitrones. The reactions were conducted under mild conditions and showed good to high yields with broad applicability. Compared to previous approaches using racemic cyclopropane reactants and chiral ligand catalysts, this study utilized enantioenriched donor-acceptor cyclopropanes as reactants with achiral catalysts.
Article
Chemistry, Multidisciplinary
Shengjie Jiang, Yanping Cai, Thayalan Rajeshkumar, Iker del Rosal, Laurent Maron, Xin Xu
Summary: This work presents the synthesis, characterization, and reactivity of the first well-defined zinc α-diazoalkyl complex. The complex reacts with a nickel catalyst to form an α-zincated phosphorus ylide, or undergoes [3+2] cycloaddition with CO2 or CO to produce a five-membered heterocyclic product. The use of CO in the cycloaddition reaction is unprecedented, demonstrating a novel CO reaction mode.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yueyao Chen, Jesse Ling, Angus B. Keto, Yun He, Kam-Hung Low, Elizabeth H. Krenske, Pauline Chiu
Summary: Epoxy and aziridinyl enolsilanes can react as oxyallylic cation equivalents in highly selective and stereoselective intramolecular (3+2) cycloadditions. Computational studies suggest that the stepwise reaction involves the conformational flexibility of the intermediate, which determines the formation of (3+2) cycloadducts. This method can be used for the synthesis of densely functionalized trans-hydrindane scaffolds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Elisa Brambilla, Camilla Pozza, Silvia Rizzato, Giorgio Abbiati, Valentina Pirovano
Summary: This paper describes an enantioselective phosphine-catalyzed [3+2] cycloaddition reaction between aza-aurones and allenoates. The reaction proceeds under mild conditions and offers 2-spirocyclopentyl indolin-3-one derivatives as a single gamma-isomer with high stereocontrol.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Mohit Tyagi, Dan E. Adolfsson, Pardeep Singh, Joergen Aden, Sanduni Wasana Jayaweera, Anna Gharibyan, Jaideep B. Bharate, Anita Kiss, Souvik Sarkar, Anders Olofsson, Fredrik Almqvist
Summary: A novel method for synthesizing cyclobutane fused thiazolino-2-pyridones was discovered, some of which showed inhibitory effects on protein fibril formation, while others were able to bind to different proteins. Several bioactive compounds tolerated this synthetic method, while also providing a potential handle for tuning bioactivity.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Cheng Zhao, Man-Zhen Gu, Yi-Yuan Chen, Xiao-Wei Hu, Yi-Bing Xu, Xiao-Min Lin, Xin-Ni Liu, Long Chen, Guo-Shu Chen, Yun-Lin Liu
Summary: A base-catalyzed divergent synthesis of multisubstituted imidazoles has been developed through TosMIC-based [3 + 2] cyclization reaction, resulting in different substitution patterns of products.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Yi Zhou, Jun-Long Qin, Wenbo Xu, Zhi-Xiang Yu
Summary: In this study, the total synthesis of clovan-2,9-dione was reported using a Rh-catalyzed multi-step reaction. The [3 + 2 + 1] cycloaddition/hydroformylation/aldol reaction sequence was employed to successfully construct the desired structure.
Article
Chemistry, Multidisciplinary
Kaixuan Wang, Chaoran Xu, Xinyue Hu, Yuqiao Zhou, Lili Lin, Xiaoming Feng
Summary: An efficient enantioselective [3+2] cycloaddition was achieved using a chiral N,N'-dioxide/Zn(ii) complex as a Lewis acid, resulting in the synthesis of a series of chiral oxa-bridged 3-spiropiperidines with high yields, excellent dr, and excellent ee values.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Applied
Ping Chen, Wei Cao, Xiangqian Li, Dayong Shi
Summary: This study presents a method for synthesizing polysubstituted five-membered heterocycles, resulting in a variety of polysubstituted furans, thiophenes, and pyrroles. The method is efficient, atom economical, and the products can be used to synthesize other useful compounds.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
