Article
Chemistry, Organic
Jianfeng Zheng, Lin Yang, Xin Dai, Lvli Chen, Luhao Tang, Yuqiao Zhou, Wei-Dong Z. Li
Summary: Magnesium-(II)-catalyzed cascade reactions of N,N'-cyclic azomethine imines with indolyl-substituted isocyanides were conducted. The method showed high tolerance towards different functional groups and had a wide range of substrates. A series of anti-pentacyclic spiroindolines with N,N'-fused heterocycle skeletons were obtained in good yields (up to 82%) with high selectivity (8.5:1 dr) under mild conditions. Interestingly, a sequential HOAc-mediated protonation led to diastereoenriched epimerization, resulting in the formation of exclusively syn-pentacyclic spiroindolines.
Article
Chemistry, Applied
Sloan Ayers, Gregory L. Beutner, Wei Ding, Carolyn Higman, Charles Pathirana, Robert Wethman
Summary: Having reliable methods to monitor catalyst activation processes is crucial for ensuring the reproducibility of catalytic reactions. For asymmetric Diels-Alder reactions, chiral oxazaborolidine or oxazaborolidinium catalysts are powerful reagents that promote these reactions with high yield and selectivity. By investigating the mechanism, several modern analytical methods are compared to quantitate the formation of oxazaborolidine catalyst from amino alcohol and boroxine, leading to useful monitoring methods for this important transformation.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Chemistry, Multidisciplinary
Shohei Furuya, Kenji Muroi, Kazuya Kanemoto, Shin-ichi Fukuzawa
Summary: The stereodivergent asymmetric synthesis of 2,5-trans/cis pyrrolidines by 1,3-dipolar cycloaddition using two different types of activated alkenes is described. The reaction using ylidene-isoxazolones as dipolarophiles produced 2,5-trans pyrrolidines, while the reaction using acyclic enones as activated alkenes afforded 2,5-cis substituted pyrrolidines.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Xingxing Wu, Reto M. Witzig, Rodolphe Beaud, Christian Fischer, Daniel Haeussinger, Christof Sparr
Summary: This study demonstrates that control over sixfold stereogenicity can be achieved through stereoselective catalysis, offering a new approach to address previously unsolvable challenges in stereocontrol. By controlling a configurationally stable stereogenic axis, selective formation of one of the six stereoisomers is achieved.
Article
Chemistry, Organic
Zhibin Yue, Boming Shen, Jie Cao, Xuling Chen, Fang Fang, Pengfei Li, Peiyuan Yu, Wenjun Li
Summary: With the use of chiral phosphoric acid as a catalyst, an enantioselective 1,6-addition of tryptamines to alkynyl 7-methylene-7H-indoles derived from tertiary alpha-(7-indolyl)methanols has been developed. This reaction provides a wide range of axially chiral tetrasubstituted allenes featuring indole and hexahydropyrrolo[2,3-b]indole units in good to high yields and with asymmetric induction. DFT calculations have been performed to elucidate the reaction mechanism and understand the origin of stereoselectivity.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Yulin Han, Anni Qin, Qian Zhang, Xue Zhang, Hui Qian, Shengming Ma
Summary: The Rh-catalyzed reaction allows for the efficient synthesis of cis-fused bicyclic products with excellent selectivity and tolerance towards synthetically useful functional groups. The proposed mechanism involves the rapid racemization of the allene moiety in the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Qiang Xiong, Ji Lu, Liu Shi, Guang-Yao Ran
Summary: In this work, a new method of annulation using phthalide-derived activated alkenes is disclosed. Under Pd(0) catalysis, an unprecedented [5 + 2] cycloaddition/ring-contraction tandem process is developed for activated tetrasubstituted alkenes derived from phthalides or butyrolactone. This method provides an efficient and mechanistically distinct approach to benzo-[5,5]-spiroketal lactones and [5,5]-spiroketal lactones bearing two vicinal tetrasubstituted centers with high diastereoselectivity.
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
Rei Tomifuji, Shunpei Murano, Satoru Teranishi, Daiki Kuroda, Takuya Kurahashr, Seijiro Matsubara
Summary: The enantioselective oxa-Diels-Alder reaction of nonactivated substrates using FeCl3 and a 1,1'-bi-2-naphthol (BINOL) derived chiral phosphoric acid as a multiple activation catalyst was successfully achieved in this study. Various oxygen-containing six-membered heterocycles were synthesized in high yields and in an enantioselective manner. Density functional theory (DFT) calculations revealed the synergistic activation of two lone pairs of an aldehyde by both Lewis acidic and Bronsted acidic moieties in the catalyst system to facilitate enantioselective addition reaction of dienes.
Article
Chemistry, Multidisciplinary
Guanghao Huang, Regis Guillot, Cyrille Kouklovsky, Boris Maryasin, Aurelien de la Torre
Summary: A broadly applicable diastereo- and enantioselective inverse-electron-demand Diels-Alder reaction of 2-pyrones and acyclic enol ethers is reported, leading to the synthesis of bridged bicyclic lactones with high yields and enantioselectivities using a copper(II)-BOX catalytic system. Mechanistic studies suggest a stepwise mechanism, and the synthetic potential of the bridged bicyclic lactones is demonstrated through the enantioselective synthesis of polyfunctional cyclohexenes and cyclohexadienes, as well as a carbasugar unit.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Manda Sathish, Fabiane M. Nachtigall, Leonardo S. Santos
Summary: In this study, an efficient enantioselective imine reduction method was developed using in situ generated Fethiosquaramides catalysts (Fe-TSQs) 3a and 3b, resulting in the synthesis of chiral tetrahydro-beta-carbolines.
Article
Chemistry, Multidisciplinary
Yubiao Hong, Tianjiao Cui, Sergei Ivlev, Xiulan Xie, Eric Meggers
Summary: This study introduces a new chiral-at-iron catalyst that can achieve high enantioselectivities in asymmetric reactions by increasing steric hindrance at the catalytic site. The catalyst was applied to the inverse electron demand hetero-Diels-Alder reaction and showed excellent diastereoselectivities and enantioselectivities. Other electron rich dienophiles, such as vinyl azide, are also suitable for this catalyst.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Mae Feo, Nikki J. Bakas, Aleksa Radovic, William Parisot, Anne Clisson, Lise-Marie Chamoreau, Mansour Haddad, Virginie Ratovelomanana-Vidal, Michael L. Neidig, Guillaume Lefevre
Summary: In this work, the design of stable iron(0) complexes with a phenanthroline-type ligand (phen) for cycloaddition catalysis is explored. The utilization of phen ligand in reduced iron oxidation states is challenging due to its strong noninnocence, resulting in unstable species. However, by strategically protecting the C4 and C7 positions of the phen ring, a stable (N,N)2Fe complex is obtained, which exhibits excellent thermal and kinetic stability and can be easily used as a precursor in catalytic processes. The electronic structure and catalytic activity of this noninnocent complex in alkyne [2 + 2 + 2] cyclizations are discussed.
Article
Chemistry, Applied
Byungjun Kim, Sukwoo Lee, Sarah Yunmi Lee
Summary: In this study, a new method was reported to successfully promote the catalytic asymmetric Diels-Alder reactions using a chiral catalyst in conjunction with a chiral isothiourea catalyst or a Bronsted acid, resulting in the synthesis of densely functionalized cyclohexenes with multiple stereocenters.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Huan Wang, Ying-Na Yue, Rui Xiong, Yu-Ting Liu, Li-Rong Yang, Ying Wang, Jia-Xing Lu
Summary: The study successfully demonstrated an electrochemically promoted asymmetric hydrogen transfer reaction of 2,2,2-trifluoroacetophenone using a chiral Ru complex, yielding high product yield and enantiomeric excess.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Tengfei Li, Fen Xu, Xincheng Li, Chunxiang Wang, Boshun Wan
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2016)
Article
Chemistry, Organic
Tengfei Li, Hao Yan, Xincheng Li, Chunxiang Wang, Boshun Wan
JOURNAL OF ORGANIC CHEMISTRY
(2016)
Article
Chemistry, Organic
Yingying Zhao, Yancheng Hu, Haolong Wang, Xincheng Li, Boshun Wan
JOURNAL OF ORGANIC CHEMISTRY
(2016)
Article
Chemistry, Organic
Yingying Zhao, Haolong Wang, Xincheng Li, Dongping Wang, Xiaoyi Xin, Boshun Wan
ORGANIC & BIOMOLECULAR CHEMISTRY
(2016)
Article
Chemistry, Organic
Yingying Zhao, Yancheng Hu, Chunxiang Wang, Xincheng Li, Boshun Wan
JOURNAL OF ORGANIC CHEMISTRY
(2017)
Article
Chemistry, Organic
Yingying Zhao, Yancheng Hu, Xincheng Li, Boshun Wan
ORGANIC & BIOMOLECULAR CHEMISTRY
(2017)
Article
Chemistry, Organic
Hao Yan, Xincheng Li, Chunxiang Wang, Boshun Wan
ORGANIC CHEMISTRY FRONTIERS
(2017)
Article
Multidisciplinary Sciences
Chunxiang Wang, Gen Luo, Masayoshi Nishiura, Guoyong Song, Atsushi Yamamoto, Yi Luo, Zhaomin Hou
Article
Chemistry, Multidisciplinary
Yingying Zhao, Chunxiang Wang, Yancheng Hu, Boshun Wan
CHEMICAL COMMUNICATIONS
(2018)
Article
Chemistry, Organic
Xiaodong Lu, Xiaoyi Xin, Boshun Wan
TETRAHEDRON LETTERS
(2018)
Article
Chemistry, Applied
Ruxia Yi, Xincheng Li, Boshun Wan
ADVANCED SYNTHESIS & CATALYSIS
(2018)