1
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Ni S, Zhou F, Zhang W, Ma J. Dehydrative Alkylation of Phenols with Alcohols via Formation of Triflate. J Org Chem 2024. [PMID: 38917459 DOI: 10.1021/acs.joc.4c00561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
An efficient synergistic trityl cation ([Ph3C][B(C6F5)4])/triflic anhydride (Tf2O) catalyzed alkylation of phenols with alcohols is reported. Benefiting from the formation of the triflate in situ, cheap and readily available active alcohols can be used as the alkylating reagents, and the reaction proceeds under mild reaction conditions with a broad substrate scope. This protocol enables the synthesis of ortho-selective phenols and 2,4,6-trisubstitued phenols containing three different alkyl groups. tert-Amyl triflate was synthesized, and mechanistic studies support a triflate-mediated alkylation process.
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Affiliation(s)
- Shengjun Ni
- College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang University, Shandong 277160, People's Republic of China
| | - Fengyan Zhou
- College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang University, Shandong 277160, People's Republic of China
| | - Wenzhi Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang University, Shandong 277160, People's Republic of China
| | - Jie Ma
- College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang University, Shandong 277160, People's Republic of China
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2
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He J, Li Z, Li R, Kou X, Liu D, Zhang W. Bimetallic Ru/Ru-Catalyzed Asymmetric One-Pot Sequential Hydrogenations for the Stereodivergent Synthesis of Chiral Lactones. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400621. [PMID: 38509867 PMCID: PMC11187880 DOI: 10.1002/advs.202400621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 02/23/2024] [Indexed: 03/22/2024]
Abstract
Asymmetric sequential hydrogenations of α-methylene γ- or δ-keto carboxylic acids are established in one-pot using a bimetallic Ru/Ru catalyst system, achieving the stereodivergent synthesis of all four stereoisomers of both chiral γ- and δ-lactones with two non-vicinal carbon stereocenters in high yields (up to 99%) and with excellent stereoselectivities (up to >99% ee and >20:1 dr). The compatibility of the two chiral Ru catalyst systems is investigated in detail, and it is found that the basicity of the reaction system plays a key role in the sequential hydrogenation processes. The protocol can be performed on a gram-scale with a low catalyst loading (up to 11000 S/C) and the resulting products allow for many transformations, particularly for the synthesis of several key intermediates useful for the preparation of chiral drugs and natural products.
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Affiliation(s)
- Jingli He
- Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsSchool of PharmacyShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China
| | - Zhaodi Li
- Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsSchool of PharmacyShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China
| | - Ruhui Li
- Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsSchool of PharmacyShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China
| | - Xuezhen Kou
- Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China
| | - Delong Liu
- Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsSchool of PharmacyShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China
| | - Wanbin Zhang
- Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsSchool of PharmacyShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China
- Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China
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3
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Li L, Yang S, Xu Z, Li S, Jiang J, Zhang YQ. Dinuclear Titanium(III)-Catalyzed Radical-Type Kinetic Resolution of Epoxides for the Enantioselective Synthesis of cis-Glycidic Esters. J Am Chem Soc 2024; 146:13546-13557. [PMID: 38690842 DOI: 10.1021/jacs.4c03346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Glycidic esters represent pivotal constituents in synthetic chemistry, offering enhanced versatility for tailoring toward a diverse array of molecular targets in comparison with simple epoxides. While considerable progress has been made in the asymmetric synthesis of trans- and trisubstituted glycidic esters, achieving enantioselective preparation of cis-glycidic esters has remained a long-standing challenge. Here, we demonstrate a selectivity-predictable modular platform for the asymmetric synthesis of cis-glycidic esters via a novel dinuclear (salen)titanium(III)-catalyzed radical-type kinetic resolution (KR) approach. This radical KR protocol operates under mild conditions and demonstrates a wide substrate scope, facilitating the synthesis of alkyl- and aryl-substituted cis-glycidic esters with high levels of regioselectivity and enantioselectivity, along with hydroxy ester byproducts representing synthetically valuable motifs as well. This study presents a unique exploration of radical-type KR applied to epoxides, effectively overcoming the steric challenges inherent in conventional nucleophilic-type methodologies typically employed in epoxide chemistry.
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Affiliation(s)
- Longfei Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Shuo Yang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Zhongyun Xu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Shengxiao Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Jie Jiang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Yong-Qiang Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
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4
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Lindner H, Amberg WM, Martini T, Fischer DM, Moore E, Carreira EM. Photo- and Cobalt-Catalyzed Synthesis of Heterocycles via Cycloisomerization of Unactivated Olefins. Angew Chem Int Ed Engl 2024; 63:e202319515. [PMID: 38415968 DOI: 10.1002/anie.202319515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 02/29/2024]
Abstract
We report a general, intramolecular cycloisomerization of unactivated olefins with pendant nucleophiles. The reaction proceeds under mild conditions and tolerates ethers, esters, protected amines, acetals, pyrazoles, carbamates, and arenes. It is amenable to N-, O-, as well as C-nucleophiles, yielding a number of different heterocycles including, but not limited to, pyrrolidines, piperidines, oxazolidinones, and lactones. Use of both a benzothiazinoquinoxaline as organophotocatalyst and a Co-salen catalyst obviates the need for stoichiometric oxidant or reductant. We showcase the utility of the protocol in late-stage drug diversification and synthesis of several small natural products.
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Affiliation(s)
- Henry Lindner
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Willi M Amberg
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Tristano Martini
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - David M Fischer
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Eléonore Moore
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Erick M Carreira
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
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5
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Höthker S, Plato A, Grimme S, Qu ZW, Gansäuer A. Stereoconvergent Approach to the Enantioselective Construction of α-Quaternary Alcohols by Radical Epoxide Allylation. Angew Chem Int Ed Engl 2024:e202405911. [PMID: 38669602 DOI: 10.1002/anie.202405911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 04/28/2024]
Abstract
We describe a highly stereoconvergent radical epoxide allylation towards diastereomerically and enantiomerically enriched α-quaternary alcohols in two steps from olefins. Our approach combines the stereospecifity and enantioselectivity of the Shi epoxidation with the unprecedented Ti(III)-promoted intramolecular radical group transfer allylation of epoxides. A directional isomerization step via configurationally labile radical intermediates enables the selective preparation of all-carbon quaternary stereocenters in a unique fashion.
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Affiliation(s)
- Sebastian Höthker
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Annika Plato
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstraße 4, 53115, Bonn, Germany
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstraße 4, 53115, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
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6
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Yu X, Xiong C, Liang Y, Zhou X, Xue C. Construction of a highly stable natural silicate-supported molybdenum catalyst for efficient epoxidation of olefins. J Colloid Interface Sci 2024; 660:490-501. [PMID: 38246052 DOI: 10.1016/j.jcis.2024.01.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/13/2024] [Accepted: 01/16/2024] [Indexed: 01/23/2024]
Abstract
Epoxides are important bulk chemicals, playing irreplaceable role in the chemical industry, but facing serious pollution and low productivity in the production process. Therefore, the development of green and efficient epoxidation of olefins by stable catalysts with low prices is of great significance. In this study, a Mo-MATP catalyst was prepared by modifying Mo(CO)₆ on attapulgite through Si-O bonding. Mo-MATP exhibits excellent performance (99% yield of cyclooctane oxide, CYCO) and stability (80% selectivity of CYCO after 17 cycles), highly tert-butyl hydroperoxide (TBHP) utilization, and extensive substrate scalability. Furthermore, the in-situ Fourier Transform Infrared Spectroscopy (FT-IR), Electron Spin-resonance Spectroscopy (ESR) and High Resolution Mass Spectrometry (HRMS) spectra suggest that TBHP would be activated by Mo-MATP to generate peroxyl radicals, which then oxidize alkenes to their corresponding epoxides. In this study, the stable loading of Mo would largely solve the problem of Mo loss during the catalytic process, thus providing a stable and dispersed Mo active center, enabling the catalyst to possess high catalytic performance and recycling stability.
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Affiliation(s)
- Xingrui Yu
- School of Chemical Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China
| | - Chao Xiong
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Institute of Green Petroleum Processing and Light Hydrocarbon Conversion, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yichao Liang
- School of Chemical Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China
| | - Xiantai Zhou
- School of Chemical Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China; Huizhou Research Institute of Sun Yat-sen University, Huizhou 516081, China.
| | - Can Xue
- School of Chemical Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China; Huizhou Research Institute of Sun Yat-sen University, Huizhou 516081, China; Guangdong Provincial Key Laboratory of Optical Chemicals, XinHuaYue Group, Maoming 525000, China.
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7
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Li F, Lan J, Li X, Chung LW. A Synergistic Bimetallic Ti/Co-Catalyzed Isomerization of Epoxides to Allylic Alcohols Enabled by Two-State Reactivity. Inorg Chem 2024; 63:6285-6295. [PMID: 38517250 DOI: 10.1021/acs.inorgchem.4c00011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Isomerization of epoxides into versatile allylic alcohols is an atom-economical synthetic method to afford vicinal bifunctional groups. Comprehensive density functional theory (DFT) calculations were carried out to elucidate the complex mechanism of a bimetallic Ti/Co-catalyzed selective isomerization of epoxides to allyl alcohols by examining several possible pathways. Our results suggest a possible mechanism involving (1) radical-type epoxide ring opening catalyzed by Cp2Ti(III)Cl leading to a Ti(IV)-bound β-alkyl radical, (2) hydrogen-atom transfer (HAT) catalyzed by the Co(II) catalyst to form the Ti(IV)-enolate and Co(III)-H intermediate, (3) protonation to give the alcohols, and (4) proton abstraction to form the Co(I) species followed by electron transfer to regenerate the active Co(II) and Ti(III) species. Moreover, bimetallic catalysis and two-state reactivity enable the key rate-determining HAT step. Furthermore, a subtle balance between dispersion-driven bimetallic processes and entropy-driven monometallic processes determines the most favorable pathway, among which the monometallic process is energetically more favorable in all steps except the vital hydrogen-atom transfer step. Our study should provide an in-depth mechanistic understanding of bimetallic catalysis.
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Affiliation(s)
- Fangfang Li
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jialing Lan
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xin Li
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lung Wa Chung
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China
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8
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Suga T, Takada R, Sakamoto M, Ukaji Y. Directing-Group-Assisted Non-Strained Ether C-O Bond Homolysis Mediated by Low-Valent Titanium. Org Lett 2024; 26:2315-2320. [PMID: 38456776 DOI: 10.1021/acs.orglett.4c00590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Ether C-O bonds are typical constituents of organic molecules that are seldom regarded as reactive functional groups except when highly strained. With the assistance of appropriate directing groups, low-valent titanium was found to homolytically cleave non-strained C-O bonds. In particular, a newly designed catechol monoether directing group rendered a route toward the activation of non-benzylic C(sp3)-O bonds. This method has been applied to conventional radical addition reactions to alkenes.
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Affiliation(s)
- Takuya Suga
- Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University,, Kakuma, Kanazawa, 920-1192, Japan
| | - Ryusei Takada
- Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University,, Kakuma, Kanazawa, 920-1192, Japan
| | - Masaya Sakamoto
- Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University,, Kakuma, Kanazawa, 920-1192, Japan
| | - Yutaka Ukaji
- Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University,, Kakuma, Kanazawa, 920-1192, Japan
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9
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Wan Y, Ramírez E, Ford A, Zhang HK, Norton JR, Li G. Cooperative Fe/Co-Catalyzed Remote Desaturation for the Synthesis of Unsaturated Amide Derivatives. J Am Chem Soc 2024; 146:4985-4992. [PMID: 38320266 DOI: 10.1021/jacs.3c14481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Unsaturated amides represent common functional groups found in natural products and bioactive molecules and serve as versatile synthetic building blocks. Here, we report an iron(II)/cobalt(II) dual catalytic system for the syntheses of distally unsaturated amide derivatives. The transformation proceeds through an iron nitrenoid-mediated 1,5-hydrogen atom transfer (1,5-HAT) mechanism. Subsequently, the radical intermediate undergoes hydrogen atom abstraction from vicinal methylene by a cobaloxime catalyst, efficiently yielding β,γ- or γ,δ-unsaturated amide derivatives under mild conditions. The efficiency of Co-mediated HAT can be tuned by varying different auxiliaries, highlighting the generality of this protocol. Remarkably, this desaturation protocol is also amenable to practical scalability, enabling the synthesis of unsaturated carbamates and ureas, which can be readily converted into various valuable molecules.
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Affiliation(s)
- Yanjun Wan
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322, United States
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Emmanuel Ramírez
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322, United States
| | - Ayzia Ford
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322, United States
| | - Harriet K Zhang
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Jack R Norton
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Gang Li
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322, United States
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10
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Lee WCC, Wang DS, Zhu Y, Zhang XP. Iron(III)-based metalloradical catalysis for asymmetric cyclopropanation via a stepwise radical mechanism. Nat Chem 2023; 15:1569-1580. [PMID: 37679462 PMCID: PMC10842623 DOI: 10.1038/s41557-023-01317-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 08/08/2023] [Indexed: 09/09/2023]
Abstract
Metalloradical catalysis (MRC) exploits the metal-centred radicals present in open-shell metal complexes as one-electron catalysts for the generation of metal-stabilized organic radicals-key intermediates that control subsequent one-electron homolytic reactions. Cobalt(II) complexes of porphyrins, as stable 15e-metalloradicals with a well-defined low-spin d7 configuration, have dominated the ongoing development of MRC. Here, to broaden MRC beyond the use of Co(II)-based metalloradical catalysts, we describe systematic studies that establish the operation of Fe(III)-based MRC and demonstrate an initial application for asymmetric radical transformations. Specifically, we report that five-coordinate iron(III) complexes of porphyrins with an axial ligand, which represent another family of stable 15e-metalloradicals with a d5 configuration, are potent metalloradical catalysts for olefin cyclopropanation with different classes of diazo compounds via a stepwise radical mechanism. This work lays a foundation and mechanistic blueprint for future exploration of Fe(III)-based MRC towards the discovery of diverse stereoselective radical reactions.
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Affiliation(s)
- Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA
| | - Duo-Sheng Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA
| | - Yiling Zhu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA.
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11
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Heinz M, Weiss G, Shizgal G, Panfilova A, Gansäuer A. Coupling Titanium and Chromium Catalysis in a Reaction Network for the Reprogramming of [BH 4 ] - as Electron Transfer and Hydrogen Atom Transfer Reagent for Radical Chemistry. Angew Chem Int Ed Engl 2023; 62:e202308680. [PMID: 37515484 DOI: 10.1002/anie.202308680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 07/31/2023]
Abstract
We describe a unique catalytic system with an efficient coupling of Ti- and Cr-catalysis in a reaction network that allows the use of [BH4 ]- as stoichiometric hydrogen atom and electron donor in catalytic radical chemistry. The key feature is a relay hydrogen atom transfer from [BH4 ]- to Cr generating the active catalysts under mild conditions. This enables epoxide reductions, regiodivergent epoxide opening and radical cyclizations that are not possible with cooperative catalysis with radicals or by epoxide reductions via Meinwald rearrangement and ensuing carbonyl reduction. No typical SN 2-type reactivity of [BH4 ]- salts is observed.
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Affiliation(s)
- Michael Heinz
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Gregor Weiss
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Grigoriy Shizgal
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Anastasia Panfilova
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
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12
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Lee WCC, Wang J, Zhu Y, Zhang XP. Asymmetric Radical Bicyclization for Stereoselective Construction of Tricyclic Chromanones and Chromanes with Fused Cyclopropanes. J Am Chem Soc 2023; 145:11622-11632. [PMID: 37129381 PMCID: PMC10249947 DOI: 10.1021/jacs.3c01618] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Asymmetric radical bicyclization processes have been developed via metalloradical catalysis (MRC) to stereoselectively construct chiral chromanones and chromanes bearing fused cyclopropanes. Through optimization of a versatile D2-symmetric chiral amidoporphyrin ligand platform, a Co(II)-metalloradical system can homolytically activate both diazomalonates and α-aryldiazomethanes containing different alkene functionalities under mild conditions for effective radical bicyclization, delivering cyclopropane-fused tricyclic chromanones and chromanes, respectively, in high yields with excellent control of both diastereoselectivities and enantioselectivities. Combined computational and experimental studies, including the electron paramagnetic resonance (EPR) detection and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) trapping of key radical intermediates, shed light on the working details of the underlying stepwise radical mechanisms of the Co(II)-catalyzed bicyclization processes. The two catalytic radical processes provide effective synthetic tools for stereoselective construction of valuable cyclopropane-fused chromanones and chromanes with newly generated contiguous stereogenic centers. As a specific demonstration of synthetic application, the Co(II)-catalyzed radical bicyclization has been employed as a key step for the first asymmetric total synthesis of the natural product (+)-Radulanin J.
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Affiliation(s)
- Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Jingyi Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Yiling Zhu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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13
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Xu P, Xie J, Wang DS, Zhang XP. Metalloradical approach for concurrent control in intermolecular radical allylic C-H amination. Nat Chem 2023; 15:498-507. [PMID: 36635599 PMCID: PMC10073309 DOI: 10.1038/s41557-022-01119-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 11/28/2022] [Indexed: 01/13/2023]
Abstract
Although they offer great potentials, the high reactivity and diverse pathways of radical chemistry pose difficult problems for applications in organic synthesis. In addition to the differentiation of multiple competing pathways, the control of various selectivities in radical reactions presents both formidable challenges and great opportunities. To regulate chemoselectivity and regioselectivity, as well as diastereoselectivity and enantioselectivity, calls for the formulation of conceptually new approaches and fundamentally different governing principles. Here we show that Co(II)-based metalloradical catalysis enables the radical chemoselective intermolecular amination of allylic C-H bonds through the employment of modularly designed D2-symmetric chiral amidoporphyrins with a tunable pocket-like environment as the supporting ligand. The reaction exhibits a remarkable convergence of regioselectivity, diastereoselectivity and enantioselectivity in a single catalytic operation. In addition to demonstrating the unique opportunities of metalloradical catalysis in controlling homolytic radical reactions, the Co(II)-catalysed convergent C-H amination offers a route to synthesize valuable chiral α-tertiary amines directly from an isomeric mixture of alkenes.
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Affiliation(s)
- Pan Xu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Boston, MA, USA
| | - Jingjing Xie
- Department of Chemistry, Merkert Chemistry Center, Boston College, Boston, MA, USA
| | - Duo-Sheng Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Boston, MA, USA
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Boston, MA, USA.
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14
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Ackerman-Biegasiewicz LKG, Kariofillis SK, Weix DJ. Multimetallic-Catalyzed C-C Bond-Forming Reactions: From Serendipity to Strategy. J Am Chem Soc 2023; 145:6596-6614. [PMID: 36913663 PMCID: PMC10163949 DOI: 10.1021/jacs.2c08615] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
The use of two or more metal catalysts in a reaction is a powerful synthetic strategy to access complex targets efficiently and selectively from simple starting materials. While capable of uniting distinct reactivities, the principles governing multimetallic catalysis are not always intuitive, making the discovery and optimization of new reactions challenging. Here, we outline our perspective on the design elements of multimetallic catalysis using precedent from well-documented C-C bond-forming reactions. These strategies provide insight into the synergy of metal catalysts and compatibility of the individual components of a reaction. Advantages and limitations are discussed to promote further development of the field.
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Affiliation(s)
| | - Stavros K. Kariofillis
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Daniel J. Weix
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, United States
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15
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Lin Q, Tong W, Shu XZ, Chen Y. Ti-Catalyzed Dehydroxylation of Tertiary Alcohols. Org Lett 2022; 24:8459-8464. [DOI: 10.1021/acs.orglett.2c03119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Quan Lin
- School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
- Center for Supramolecular Chemistry and Catalysis and Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
| | - Weiqi Tong
- Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
| | - Xing-Zhong Shu
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, People’s Republic of China
| | - Yunrong Chen
- Center for Supramolecular Chemistry and Catalysis and Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
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16
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Yuan GC, Guo P, Wang ZH, Zhu L, He X, Li Y, Ye KY. Synthesis of Indeno[1,2- c]furans via Cobalt-Catalyzed Radical–Polar Crossover [3 + 2] Cycloaddition of o-Alkynylaryl β-Dicarbonyls. Org Lett 2022; 24:8197-8201. [DOI: 10.1021/acs.orglett.2c03297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Guo-Cai Yuan
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Peng Guo
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Zhi-Hua Wang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Lingyun Zhu
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Xinglei He
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Yuanming Li
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Ke-Yin Ye
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
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17
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Wu X, Gannett CN, Liu J, Zeng R, Novaes LFT, Wang H, Abruña HD, Lin S. Intercepting Hydrogen Evolution with Hydrogen-Atom Transfer: Electron-Initiated Hydrofunctionalization of Alkenes. J Am Chem Soc 2022; 144:17783-17791. [PMID: 36137298 DOI: 10.1021/jacs.2c08278] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hydrogen-atom transfer mediated by earth-abundant transition-metal hydrides (M-Hs) has emerged as a powerful tool in organic synthesis. Current methods to generate M-Hs most frequently rely on oxidatively initiated hydride transfer. Herein, we report a reductive approach to generate Co-H, which allows for canonical hydrogen evolution reactions to be intercepted by hydrogen-atom transfer to an alkene. Electroanalytical and spectroscopic studies provided mechanistic insights into the formation and reactivity of Co-H, which enabled the development of two new alkene hydrofunctionalization reactions.
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Affiliation(s)
- Xiangyu Wu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Cara N Gannett
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jinjian Liu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Rui Zeng
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Luiz F T Novaes
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Hongsen Wang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Héctor D Abruña
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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18
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Zhang K, Ren BH, Liu XF, Wang LL, Zhang M, Ren WM, Lu XB, Zhang WZ. Direct and Selective Electrocarboxylation of Styrene Oxides with CO2 for Accessing β‐Hydroxy Acids. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ke Zhang
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Bai-Hao Ren
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Xiao-Fei Liu
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Lin-Lin Wang
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Min Zhang
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Wei-Min Ren
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Xiao-Bing Lu
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Wen-Zhen Zhang
- Dalian University of Technology State Key Laboratory of Fine Chemicals E-330 West Campus, No.2 Linggong Road, High-Tech Zone 116024 Dalian CHINA
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19
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Zhang K, Ren BH, Liu XF, Wang LL, Zhang M, Ren WM, Lu XB, Zhang WZ. Direct and Selective Electrocarboxylation of Styrene Oxides with CO2 for Accessing β-Hydroxy Acids. Angew Chem Int Ed Engl 2022; 61:e202207660. [PMID: 35862121 DOI: 10.1002/anie.202207660] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Indexed: 11/08/2022]
Abstract
Highly selective and direct electroreductive ring-opening carboxylation of epoxides with CO2 in an undivided cell is reported. This reaction shows broad substrate scopes within styrene oxides under mild conditions, providing practical and scalable access to important synthetic intermediate β-hydroxy acids. Mechanistic studies show that CO2 functions not only as a carboxylative reagent in this reaction but also as a promoter to enable efficient and chemoselective transformation of epoxides under additive-free electrochemical conditions. Cathodically generated α-radical and α-carbanion intermediates lead to the regioselective formation of α-carboxylation products.
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Affiliation(s)
- Ke Zhang
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, CHINA
| | - Bai-Hao Ren
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, CHINA
| | - Xiao-Fei Liu
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, CHINA
| | - Lin-Lin Wang
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, CHINA
| | - Min Zhang
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, CHINA
| | - Wei-Min Ren
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, CHINA
| | - Xiao-Bing Lu
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, CHINA
| | - Wen-Zhen Zhang
- Dalian University of Technology, State Key Laboratory of Fine Chemicals, E-330 West Campus, No.2 Linggong Road, High-Tech Zone, 116024, Dalian, CHINA
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20
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Wu X, Chang Y, Lin S. Titanium radical redox catalysis: Recent innovations in catalysts, reactions, and modes of activation. Chem 2022; 8:1805-1821. [DOI: 10.1016/j.chempr.2022.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Lang K, Hu Y, Cindy Lee WC, Zhang XP. Combined radical and ionic approach for the enantioselective synthesis of β-functionalized amines from alcohols. NATURE SYNTHESIS 2022; 1:548-557. [PMID: 36713299 PMCID: PMC9881596 DOI: 10.1038/s44160-022-00107-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Chiral amines are among the most important organic compounds and have widespread applications. Enantioselective construction of chiral amines is a major aim in organic synthesis. Among synthetic methods, direct functionalization of omnipresent C-H bonds with common organic nitrogen compounds represents one of the most attractive strategies. However, C-H amination strategies are largely limited to constructing a specific type of N-heterocycles or amine derivatives. To maximize the synthetic potential of asymmetric C-H amination, we report here an approach that unites the complementary reactivities of radical and ionic chemistry for streamlined synthesis of functionalized chiral amines. This synthesis merges the development of an enantioselective radical process for 1,5-C(sp 3)-H amination of alkoxysulfonyl azides via Co(II)-based metalloradical catalysis with an enantiospecific ionic process for ring-opening of the resulting five-membered chiral sulfamidates by nucleophiles. Given that alkoxysulfonyl azides are derived from the corresponding alcohols, this approach offers a powerful synthetic tool for enantioselective β-C-H amination of common alcohols while converting the hydroxy group to other functionalities through formal nucleophilic substitution.
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Affiliation(s)
- Kai Lang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA
| | - Yang Hu
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA
| | - X. Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA.,
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22
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Nakagawa M, Matsuki Y, Nagao K, Ohmiya H. A Triple Photoredox/Cobalt/Brønsted Acid Catalysis Enabling Markovnikov Hydroalkoxylation of Unactivated Alkenes. J Am Chem Soc 2022; 144:7953-7959. [PMID: 35476545 DOI: 10.1021/jacs.2c00527] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We demonstrate Markovnikov hydroalkoxylation of unactivated alkenes using alcohols through a triple catalysis consisting of photoredox, cobalt, and Brønsted acid catalysts under visible light irradiation. The triple catalysis realizes three key elementary steps in a single catalytic cycle: (1) Co(III) hydride generation by photochemical reduction of Co(II) followed by protonation, (2) metal hydride hydrogen atom transfer (MHAT) of alkenes by Co(III) hydride, and (3) oxidation of the alkyl Co(III) complex to alkyl Co(IV). The precise control of protons and electrons by the three catalysts allows the elimination of strong acids and external reductants/oxidants that are required in the conventional methods.
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Affiliation(s)
- Masanari Nakagawa
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Yuki Matsuki
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Kazunori Nagao
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Hirohisa Ohmiya
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.,JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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23
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Hong P, Song X, Huang Z, Tan K, Wu A, Lu X. Insights into the Mechanism of Metal-Catalyzed Transformation of Oxime Esters: Metal-Bound Radical Pathway vs Free Radical Pathway. J Org Chem 2022; 87:6014-6024. [PMID: 35389656 DOI: 10.1021/acs.joc.2c00273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Controlling of radical reactivity by binding a radical to the metal center is an elegant strategy to overcome the challenge that radical intermediates are "too reactive to be selective". Yet, its application has seemingly been limited to a few strained-ring substrates, azide compounds, and diazo compounds. Meanwhile, first-row transition-metal-catalyzed (mainly, Fe, Ni, Cu) transformations of oxime esters have been reported recently in which the activation processes are assumed to follow free-radical mechanisms. In this work, we show by means of density functional theory calculations that the activation of oxime esters catalyzed by Fe(II) and Cu(I) catalysts more likely affords a metal-bound iminyl radical, rather than the presumed free iminyl radical, and the whole process follows a metal-bound radical mechanism. The as-formed metal-bound radical intermediates are an Fe(III)-iminyl radical (Stotal = 2, SFe = 5/2, and Siminyl = -1/2) and a Cu(II)-iminyl radical (Stotal = 0, SCu = 1/2, and Siminyl = -1/2). The discovery of such novel substrates affording metal-bound radical intermediates may facilitate the experimental design of metal-catalyzed asymmetric synthesis using oxime esters to achieve the desired enantioselectivity.
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Affiliation(s)
- Pan Hong
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory for Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xiaolin Song
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory for Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Zhengqi Huang
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory for Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Kai Tan
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory for Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Anan Wu
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory for Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xin Lu
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory for Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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24
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Chen M, Wu ZJ, Song J, Xu HC. Electrocatalytic Allylic C-H Alkylation Enabled by a Dual-Function Cobalt Catalyst. Angew Chem Int Ed Engl 2022; 61:e202115954. [PMID: 35129253 DOI: 10.1002/anie.202115954] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Indexed: 12/11/2022]
Abstract
The direct functionalization of allylic C-H bonds with nucleophiles minimizes pre-functionalization and converts inexpensive, abundantly available materials to value-added alkenyl-substituted products but remains challenging. Here we report an electrocatalytic allylic C-H alkylation reaction with carbon nucleophiles employing an easily available cobalt-salen complex as the molecular catalyst. These C(sp3 )-H/C(sp3 )-H cross-coupling reactions proceed through H2 evolution and require no external chemical oxidants. Importantly, the mild conditions and unique electrocatalytic radical process ensure excellent functional group tolerance and substrate compatibility with both linear and branched terminal alkenes. The synthetic utility of the electrochemical method is highlighted by its scalability (up to 200 mmol scale) under low loading of electrolyte (down to 0.05 equiv) and its successful application in the late-stage functionalization of complex structures.
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Affiliation(s)
- Ming Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Innovative Collaboration Center of Chemistry for Energy Materials, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Zheng-Jian Wu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Innovative Collaboration Center of Chemistry for Energy Materials, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Jinshuai Song
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China
| | - Hai-Chao Xu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Innovative Collaboration Center of Chemistry for Energy Materials, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
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25
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Yao C, Williams ADN, Gu Y, Norton JR. Isomerization of Aziridines to Allyl Amines via Titanium and Chromium Cooperative Catalysis. J Org Chem 2022; 87:4991-4997. [PMID: 35303410 DOI: 10.1021/acs.joc.1c03054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A Ti/Cr cooperative catalyst isomerizes aziridines to allyl amines under mild conditions. The reaction tolerates a broad range of aziridines with various nitrogen substituents. The titanium catalyst is most successful in opening 1,2-disubstituted aziridines, forming radical intermediates in a highly regioselective manner. The chromium catalyst appears to abstract an H• from these radical intermediates and then return the H• to the titanium system in the form of an H+ and an electron. The reaction is complementary to previous reports on the isomerization of aziridines to allyl amines.
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Affiliation(s)
- Chengbo Yao
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Alana D N Williams
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Yiting Gu
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Jack R Norton
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
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26
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Wang J, Xie J, Lee WCC, Wang DS, Zhang XP. Radical differentiation of two ester groups in unsymmetrical diazomalonates for highly asymmetric olefin cyclopropanation. CHEM CATALYSIS 2022; 2:330-344. [PMID: 35494099 PMCID: PMC9049825 DOI: 10.1016/j.checat.2021.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Diazomalonates have been demonstrated as effective metalloradicophiles for asymmetric radical olefin cyclopropanation via Co(II)-metalloradical catalysis (MRC). Supported by D 2-symmetric chiral amidoporphyrin ligand, Co(II)-based metalloradical system can efficiently activate unsymmetrical methyl phenyl diazomalonate (MPDM) with effective differentiation of the two ester groups for asymmetric cyclopropanation, enabling stereoselective construction of 1,1-cyclopropanediesters bearing two contiguous chiral centers, including all-carbon quaternary stereogenic center. The Co(II)-catalyzed asymmetric cyclopropanation, which operates at room temperature without slow addition of the diazo compound, is generally applicable to broad-ranging olefins and tolerates various functionalities, providing a streamlined synthesis of chiral 1,1-cyclopropanediesters in high yields with both high diastereoselectivity and enantioselectivity. Combined computational and experimental studies support the underlying stepwise radical mechanism for Co(II)-catalyzed cyclopropanation. In addition to functioning as 1,3-dipoles for forming five-membered structures, enantioenriched (E)-1,1-cyclopropanediesters serve as useful building blocks for stereoselective synthesis of different cyclopropane derivatives. In addition, the enantioenriched (E)-1,1-cyclopropanediesters can be stereoselectively converted to (Z)-diastereomers.
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Affiliation(s)
- Jingyi Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - Jingjing Xie
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - Duo-Sheng Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - X. Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
- Lead contact
- Correspondence:
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27
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Chen M, Wu Z, Song J, Xu H. Electrocatalytic Allylic C−H Alkylation Enabled by a Dual‐Function Cobalt Catalyst**. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ming Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces Innovative Collaboration Center of Chemistry for Energy Materials Key Laboratory of Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Zheng‐Jian Wu
- State Key Laboratory of Physical Chemistry of Solid Surfaces Innovative Collaboration Center of Chemistry for Energy Materials Key Laboratory of Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Jinshuai Song
- Green Catalysis Center, and College of Chemistry Zhengzhou University Zhengzhou 450001 China
| | - Hai‐Chao Xu
- State Key Laboratory of Physical Chemistry of Solid Surfaces Innovative Collaboration Center of Chemistry for Energy Materials Key Laboratory of Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
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28
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Ke J, Lee WCC, Wang X, Wang Y, Wen X, Zhang XP. Metalloradical Activation of In Situ-Generated α-Alkynyldiazomethanes for Asymmetric Radical Cyclopropanation of Alkenes. J Am Chem Soc 2022; 144:2368-2378. [PMID: 35099966 PMCID: PMC9032462 DOI: 10.1021/jacs.1c13154] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
α-Alkynyldiazomethanes, generated in situ from the corresponding sulfonyl hydrazones in the presence of a base, can serve as effective metalloradicophiles in Co(II)-based metalloradical catalysis (MRC) for asymmetric cyclopropanation of alkenes. With D2-symmetric chiral amidoporphyrin 2,6-DiMeO-QingPhyrin as the optimal supporting ligand, the Co(II)-based metalloradical system can efficiently activate different α-alkynyldiazomethanes at room temperature for highly asymmetric cyclopropanation of a broad range of alkenes. This catalytic radical process provides a general synthetic tool for stereoselective construction of alkynyl cyclopropanes in high yields with high both diastereoselectivity and enantioselectivity. Combined computational and experimental studies offer several lines of evidence in support of the underlying stepwise radical mechanism for the Co(II)-catalyzed olefin cyclopropanation involving a unique α-metalloradical intermediate that is associated with two resonance forms of α-Co(III)-propargyl radical and γ-Co(III)-allenyl radical. The resulting enantioenriched alkynyl cyclopropanes, as showcased with several stereospecific transformations, may serve as valuable chiral building blocks for stereoselective organic synthesis.
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Affiliation(s)
- Jing Ke
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Xiaoxu Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Yong Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Xin Wen
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X. Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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29
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Mondal S, Dumur F, Gigmes D, Sibi MP, Bertrand MP, Nechab M. Enantioselective Radical Reactions Using Chiral Catalysts. Chem Rev 2022; 122:5842-5976. [DOI: 10.1021/acs.chemrev.1c00582] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Shovan Mondal
- Department of Chemistry, Syamsundar College, Shyamsundar 713424, West Bengal, India
| | - Frédéric Dumur
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, F-13390e Marseille, France
| | - Didier Gigmes
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, F-13390e Marseille, France
| | - Mukund P. Sibi
- Department of Chemistry and Biochemistry North Dakota State University, Fargo, North Dakota 58108, United States
| | - Michèle P. Bertrand
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, F-13390e Marseille, France
| | - Malek Nechab
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, F-13390e Marseille, France
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30
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Nájera C, Foubelo F, Sansano JM, Yus M. Enantioselective desymmetrization reactions in asymmetric catalysis. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132629] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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31
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Abstract
Selective hydrogenation of epoxides would be a direct and powerful approach for alcohol synthesis, but it has proven to be elusive. Here, electrochemically epoxide hydrogenation using electrons and protons as reductants is reported. A wide range of primary, secondary, and tertiary alcohols can be achieved through selective Markovnikov or anti-Markovnikov ring opening in the absence of transition metals. Mechanistic investigations revealed that the regioselectivity is controlled by the thermodynamic stabilities of the in situ generated benzyl radicals for aryl-substituted epoxides and the kinetic tendency for Markovnikov selective ring opening for alkyl-substituted epoxides.
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Affiliation(s)
- Cheng Huang
- The Institute for Advanced Studies (IAS), Wuhan University, Wuhan 430072, P. R. China
| | - Wan Ma
- The Institute for Advanced Studies (IAS), Wuhan University, Wuhan 430072, P. R. China
| | - Xuelian Zheng
- The Institute for Advanced Studies (IAS), Wuhan University, Wuhan 430072, P. R. China
| | - Minghao Xu
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China
| | - Xiaotian Qi
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China
| | - Qingquan Lu
- The Institute for Advanced Studies (IAS), Wuhan University, Wuhan 430072, P. R. China.,Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University, Wuhan 430062, P. R. China
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32
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Li TZ, Yang XT, Wang JP, Geng CA, Ma YB, Su LH, Zhang XM, Chen JJ. Biomimetic Synthesis of Lavandiolides H, I, and K and Artematrolide F via Diels-Alder Reaction. Org Lett 2021; 23:8380-8384. [PMID: 34634203 DOI: 10.1021/acs.orglett.1c03120] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The biomimetic synthesis of guaianolide dimers lavandiolides H, I, and K and artematrolide F containing a spirolactone moiety has been accomplished for the first time from naturally abundant arglabin in four to six steps with an overall yield up to 60%, and a series of natural product-like guaianolide dimers, trimer, and tetramer were also successfully synthesized. Notably, the trimeric compound exhibited antihepatoma cytotoxicity more potent than that of sorafenib with IC50 values of 6.2 μM (HepG2), 6.8 μM (Huh7), and 7.2 μM (SK-HEP-1).
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Affiliation(s)
- Tian-Ze Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Xiao-Tong Yang
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Jin-Ping Wang
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Chang-An Geng
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Yun-Bao Ma
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Li-Hua Su
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Xue-Mei Zhang
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Ji-Jun Chen
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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33
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Zhang D, Li H, Yi D, Tu S, Qi Z, Wei S, Fu Q, Fu H, Du X. Ti-catalyzed regioselective ring-opening alkynylation of epoxides with haloalkynes. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Younas SL, Streuff J. Kinetic Analysis Uncovers Hidden Autocatalysis and Inhibition Pathways in Titanium(III)-Catalyzed Ketone-Nitrile Couplings. ACS Catal 2021. [DOI: 10.1021/acscatal.1c02870] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Sara L. Younas
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Jan Streuff
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
- Department of Chemistry—BMC, Uppsala University, Husargatan 3, 75237 Uppsala, Sweden
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35
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Xie J, Xu P, Zhu Y, Wang J, Lee WCC, Zhang XP. New Catalytic Radical Process Involving 1,4-Hydrogen Atom Abstraction: Asymmetric Construction of Cyclobutanones. J Am Chem Soc 2021; 143:11670-11678. [PMID: 34292709 PMCID: PMC8399868 DOI: 10.1021/jacs.1c04968] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
While alkyl radicals have been well demonstrated to undergo both 1,5- and 1,6-hydrogen atom abstraction (HAA) reactions, 1,4-HAA is typically a challenging process both entropically and enthalpically. Consequently, chemical transformations based on 1,4-HAA have been scarcely developed. Guided by the general mechanistic principles of metalloradical catalysis (MRC), 1,4-HAA has been successfully incorporated as a key step, followed by 4-exo-tet radical substitution (RS), for the development of a new catalytic radical process that enables asymmetric 1,4-C-H alkylation of diazoketones for stereoselective construction of cyclobutanone structures. The key to success is the optimization of the Co(II)-based metalloradical catalyst through judicious modulation of D2-symmetric chiral amidoporphyrin ligand to adopt proper steric, electronic, and chiral environments that can utilize a network of noncovalent attractive interactions for effective activation of the substrate and subsequent radical intermediates. Supported by an optimal chiral ligand, the Co(II)-based metalloradical system, which operates under mild conditions, is capable of 1,4-C-H alkylation of α-aryldiazoketones with varied electronic and steric properties to construct chiral α,β-disubstituted cyclobutanones in good to high yields with high diastereoselectivities and enantioselectivities, generating dinitrogen as the only byproduct. Combined computational and experimental studies have shed light on the mechanistic details of the new catalytic radical process, including the revelation of facile 1,4-HAA and 4-exo-tet-RS steps. The resulting enantioenriched α,β-disubstituted cyclobutanones, as showcased with several enantiospecific transformations to other types of cyclic structures, may find useful applications in stereoselective organic synthesis.
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Affiliation(s)
- Jingjing Xie
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Pan Xu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Yiling Zhu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Jingyi Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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36
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Wood DP, Guan W, Lin S. Titanium and Cobalt Bimetallic Radical Redox Relay for the Isomerization of N-Bz Aziridines to Allylic Amides. SYNTHESIS-STUTTGART 2021; 53:4213-4220. [PMID: 34764520 PMCID: PMC8579959 DOI: 10.1055/s-0037-1610779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Herein a bimetallic radical redox-relay strategy is employed to generate alkyl radicals under mild conditions with titanium(III) catalysis and terminated via hydrogen atom transfer with cobalt(II) catalysis to enact base-free isomerizations of N-Bz aziridines to N-Bz allylic amides. This reaction provides an alternative strategy for the synthesis of allylic amides from alkenes via a three-step sequence to accomplish a formal transpositional allylic amination.
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Affiliation(s)
- Devin P Wood
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - Weiyang Guan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
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37
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Zhang C, Wang DS, Lee WCC, McKillop AM, Zhang XP. Controlling Enantioselectivity and Diastereoselectivity in Radical Cascade Cyclization for Construction of Bicyclic Structures. J Am Chem Soc 2021; 143:11130-11140. [PMID: 34260202 PMCID: PMC8399859 DOI: 10.1021/jacs.1c04719] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Radical cascade cyclization reactions are highly attractive synthetic tools for the construction of polycyclic molecules in organic synthesis. While it has been successfully implemented in diastereoselective synthesis of natural products and other complex compounds, radical cascade cyclization faces a major challenge of controlling enantioselectivity. As the first application of metalloradical catalysis (MRC) for controlling enantioselectivity as well as diastereoselectivity in radical cascade cyclization, we herein report the development of a Co(II)-based catalytic system for asymmetric radical bicyclization of 1,6-enynes with diazo compounds. Through the fine-tuning of D2-symmetric chiral amidoporphyrins as the supporting ligands, the Co(II)-catalyzed radical cascade process, which proceeds in a single operation under mild conditions, enables asymmetric construction of multisubstituted cyclopropane-fused tetrahydrofurans bearing three contiguous stereogenic centers, including two all-carbon quaternary centers, in high yields with excellent stereoselectivities. Combined computational and experimental studies have shed light on the underlying stepwise radical mechanism for this new Co(II)-based cascade bicyclization that involves the relay of several Co-supported C-centered radical intermediates, including α-, β-, γ-, and ε-metalloalkyl radicals. The resulting enantioenriched cyclopropane-fused tetrahydrofurans that contain a trisubstituted vinyl group at the bridgehead, as showcased in several stereospecific transformations, may serve as useful intermediates for stereoselective organic synthesis. The successful demonstration of this new asymmetric radical process via Co(II)-MRC points out a potentially general approach for controlling enantioselectivity as well as diastereoselectivity in synthetically attractive radical cascade reactions.
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Affiliation(s)
- Congzhe Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Duo-Sheng Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Alexander M McKillop
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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38
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Wang X, Ke J, Zhu Y, Deb A, Xu Y, Zhang XP. Asymmetric Radical Process for General Synthesis of Chiral Heteroaryl Cyclopropanes. J Am Chem Soc 2021; 143:11121-11129. [PMID: 34282613 PMCID: PMC8399893 DOI: 10.1021/jacs.1c04655] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A highly efficient catalytic method has been developed for asymmetric radical cyclopropanation of alkenes with in situ-generated α-heteroaryldiazomethanes via Co(II)-based metalloradical catalysis (MRC). Through fine-tuning the cavity-like environments of newly-synthesized D2-symmetric chiral amidoporphyrins as the supporting ligand, the optimized Co(II)-based metalloradical system is broadly applicable to α-pyridyl and other α-heteroaryldiazomethanes for asymmetric cyclopropanation of wide-ranging alkenes, including several types of challenging substrates. This new catalytic methodology provides a general access to valuable chiral heteroaryl cyclopropanes in high yields with excellent both diastereoselectivities and enantioselectivities. Combined computational and experimental studies further support the underlying stepwise radical mechanism of the Co(II)-based olefin cyclopropanation involving α- and γ-metalloalkyl radicals as the key intermediates.
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Affiliation(s)
- Xiaoxu Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Jing Ke
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Yiling Zhu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Arghya Deb
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Yijie Xu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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39
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Noji M, Baba M, Hirabe R, Hayashi S, Takanami T. Proton-accelerated Lewis acid catalysis for stereo- and regioselective isomerization of epoxides to allylic alcohols. Chem Commun (Camb) 2021; 57:7104-7107. [PMID: 34179905 DOI: 10.1039/d1cc02840e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The isomerization of epoxides to allylic alcohols was developed via proton-accelerated Lewis acid catalysis. The addition of tBuOH as a proton source is the key to the efficient catalytic cycle. Trisubstituted epoxides, including enantioenriched derivatives, were selectively converted to secondary-allylic alcohols without loss of enantiopurity.
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Affiliation(s)
- Masahiro Noji
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
| | - Misako Baba
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
| | - Rina Hirabe
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
| | - Satoshi Hayashi
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
| | - Toshikatsu Takanami
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
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40
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Cai CY, Wu ZJ, Liu JY, Chen M, Song J, Xu HC. Tailored cobalt-salen complexes enable electrocatalytic intramolecular allylic C-H functionalizations. Nat Commun 2021; 12:3745. [PMID: 34145285 PMCID: PMC8213807 DOI: 10.1038/s41467-021-24125-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 06/03/2021] [Indexed: 12/04/2022] Open
Abstract
Oxidative allylic C–H functionalization is a powerful tool to streamline organic synthesis as it minimizes the need for functional group activation and generates alkenyl-substituted products amenable to further chemical modifications. The intramolecular variants can be used to construct functionalized ring structures but remain limited in scope and by their frequent requirement for noble metal catalysts and stoichiometric chemical oxidants. Here we report an oxidant-free, electrocatalytic approach to achieve intramolecular oxidative allylic C–H amination and alkylation by employing tailored cobalt-salen complexes as catalysts. These reactions proceed through a radical mechanism and display broad tolerance of functional groups and alkene substitution patterns, allowing efficient coupling of di-, tri- and even tetrasubstituted alkenes with N- and C-nucleophiles to furnish high-value heterocyclic and carbocyclic structures. Oxidative allylic C–H functionalizations minimise the need for functional group activation and generate alkenyl-substituted products amenable to further chemical modifications. Here the authors report an oxidant-free, electrocatalytic approach to achieve intramolecular oxidative allylic C–H amination and alkylation by employing tailored cobalt-salen complexes as catalysts.
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Affiliation(s)
- Chen-Yan Cai
- Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Zheng-Jian Wu
- Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Ji-Ying Liu
- Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, China
| | - Ming Chen
- Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Jinshuai Song
- Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, China
| | - Hai-Chao Xu
- Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
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41
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Cindy Lee WC, Wang DS, Zhang C, Xie J, Li B, Zhang XP. Asymmetric Radical Cyclopropanation of Dehydroaminocarboxylates: Stereoselective Synthesis of Cyclopropyl α-Amino Acids. Chem 2021; 7:1588-1601. [PMID: 34693072 DOI: 10.1016/j.chempr.2021.03.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A catalytic radical process has been developed for asymmetric cyclopropanation of dehydroaminocarboxylates with in situ-generated α-aryldiazomethanes via Co(II)-based metalloradical catalysis (MRC). Through fine-tuning the environments of D 2-symmetric chiral amidoporphyrin platform as the supporting ligands, the Co(II)-metalloradical system can effectively activate various α-aryldiazomethanes to cyclopropanate different dehydroaminocarboxylates under mild conditions, enabling the stereoselective synthesis of chiral cyclopropyl α-amino acid derivatives. In addition to high yields and excellent enantioselectivities, the Co(II)-catalyzed asymmetric radical cyclopropanation exhibits (Z)-diastereoselectivity, which is the opposite of uncatalyzed thermal reaction. Combined computational and experimental studies support a stepwise radical mechanism for the Co(II)-catalyzed cyclopropanation reaction. The resulting enantioenriched (Z)-α-amino-β-arylcyclopropanecarboxylates, as showcased for the efficient synthesis of dipeptides, may serve as unique non-proteinogenic amino acid building blocks for the design and preparation of novel peptides with restricted conformations.
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Affiliation(s)
- Wan-Chen Cindy Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Duo-Sheng Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Congzhe Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Jingjing Xie
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Bo Li
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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42
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Sumiyama K, Toriumi N, Iwasawa N. Use of Isopropyl Alcohol as a Reductant for Catalytic Dehydoxylative Dimerization of Benzylic Alcohols Utilizing Ti−O Bond Photohomolysis. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100286] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Keiichi Sumiyama
- Department of Chemistry Tokyo Institute of Technology O-okayama, Meguro-ku Tokyo 152-8551 Japan
| | - Naoyuki Toriumi
- Department of Chemistry Tokyo Institute of Technology O-okayama, Meguro-ku Tokyo 152-8551 Japan
| | - Nobuharu Iwasawa
- Department of Chemistry Tokyo Institute of Technology O-okayama, Meguro-ku Tokyo 152-8551 Japan
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43
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Riart-Ferrer X, Sang P, Tao J, Xu H, Jin LM, Lu H, Cui X, Wojtas L, Zhang XP. Metalloradical activation of carbonyl azides for enantioselective radical aziridination. Chem 2021; 7:1120-1134. [PMID: 33869888 DOI: 10.1016/j.chempr.2021.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Organic azides have been increasingly employed as nitrogen sources for catalytic olefine aziridination due to their ease of preparation and generation of benign N2 as the only byproduct. Among common organic azides, carbonyl azides have not been previously demonstrated as effective nitrogen sources for intermolecular olefin aziridination despite the synthetic utilities of N-carbonyl aziridines. As a new application of metalloradical catalysis, we have developed a catalytic system that can effectively employ the carbonyl azide TrocN3 for highly asymmetric aziridination of alkenes at room temperature. The resulting enantioenriched N-Trocaziridines have been shown as valuable chiral synthons for stereoselective synthesis of other chiral aziridines and various chiral amines. The Co(II)-based metalloradical system, which proceeds with distinctive stepwise radical mechanism, may provide a general method for asymmetric synthesis of chiral aziridines from alkenes with organic azides.
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Affiliation(s)
- Xavier Riart-Ferrer
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
- These authors contributed equally
| | - Peng Sang
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
- These authors contributed equally
| | - Jingran Tao
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
- These authors contributed equally
| | - Hao Xu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - Li-Mei Jin
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - Hongjian Lu
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Xin Cui
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Lukasz Wojtas
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
- Lead contact
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44
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Kern C, Selau J, Streuff J. A Titanium-Catalyzed Reductive α-Desulfonylation. Chemistry 2021; 27:6178-6182. [PMID: 33539578 PMCID: PMC8048938 DOI: 10.1002/chem.202005400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/09/2021] [Indexed: 12/14/2022]
Abstract
A titanium(III)-catalyzed desulfonylation gives access to functionalized alkyl nitrile building blocks from α-sulfonyl nitriles, circumventing traditional base-mediated α-alkylation conditions and strong single electron donors. The reaction tolerates numerous functional groups including free alcohols, esters, amides, and it can be applied also to the α-desulfonylation of ketones. In addition, a one-pot desulfonylative alkylation is demonstrated. Preliminary mechanistic studies indicate a catalyst-dependent mechanism involving a homolytic C-S cleavage.
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Affiliation(s)
- Christoph Kern
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
| | - Jan Selau
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
| | - Jan Streuff
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
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45
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Li Q, Liu R, Wei Y, Shi M. Silver/Rhodium Relay Catalysis Enables C−H Functionalization of
In Situ
Generated Isoquinolines with Sulfoxonium Ylides: Construction of Hexahydrodibenzo[
a
,
g
]quinolizine Scaffolds. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100141] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Quanzhe Li
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, School of Chemistry & Molecular Engineering East China University of Science and Technology Meilong Road No.130 Shanghai 200237 People's Republic of China
| | - Ruixing Liu
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 354 Fenglin Lu Shanghai 200032 People's Republic of China
| | - Yin Wei
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 354 Fenglin Lu Shanghai 200032 People's Republic of China
| | - Min Shi
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, School of Chemistry & Molecular Engineering East China University of Science and Technology Meilong Road No.130 Shanghai 200237 People's Republic of China
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 354 Fenglin Lu Shanghai 200032 People's Republic of China
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46
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Li Y, Chen F, Zhu S, Chu L. Photoinduced triiodide-mediated [3 + 2] cycloaddition of N-tosyl aziridines and alkenes. Org Chem Front 2021. [DOI: 10.1039/d1qo00102g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A photoinduced triiodide-mediated [3 + 2] cycloaddition of N-Ts aziridines and alkenes is described herein. This operationally simple protocol enables regioselective access to a wide range of substituted pyrrolidines under mild-free conditions.
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Affiliation(s)
- Yuanbo Li
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials
- Center for Advanced Low-Dimension Materials
- College of Chemistry
- Chemical Engineering and Biotechnology
- Donghua University
| | - Fan Chen
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials
- Center for Advanced Low-Dimension Materials
- College of Chemistry
- Chemical Engineering and Biotechnology
- Donghua University
| | - Shengqing Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials
- Center for Advanced Low-Dimension Materials
- College of Chemistry
- Chemical Engineering and Biotechnology
- Donghua University
| | - Lingling Chu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials
- Center for Advanced Low-Dimension Materials
- College of Chemistry
- Chemical Engineering and Biotechnology
- Donghua University
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Wan Q, Chen L, Li S, Kang Q, Yuan Y, Du Y. Enantioselective Synthesis of Multisubstituted Spirocyclopentane Oxindoles Enabled by Pd/Chiral Rh(III) Complex Synergistic Catalysis. Org Lett 2020; 22:9539-9544. [PMID: 33263254 DOI: 10.1021/acs.orglett.0c03588] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Qian Wan
- College of Chemistry, Fuzhou University, Fuzhou 350108, P. R. China
| | - Liang Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yangqiao Road West, Fuzhou 350002, P. R. China
| | - Shiwu Li
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yangqiao Road West, Fuzhou 350002, P. R. China
| | - Qiang Kang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yangqiao Road West, Fuzhou 350002, P. R. China
| | - Yaofeng Yuan
- College of Chemistry, Fuzhou University, Fuzhou 350108, P. R. China
| | - Yu Du
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yangqiao Road West, Fuzhou 350002, P. R. China
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Lang K, Li C, Kim I, Zhang XP. Enantioconvergent Amination of Racemic Tertiary C-H Bonds. J Am Chem Soc 2020; 142:20902-20911. [PMID: 33249845 DOI: 10.1021/jacs.0c11103] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Racemization is considered to be an intrinsic stereochemical feature of free radical chemistry as can be seen in traditional radical halogenation reactions of optically active tertiary C-H bonds. If the facile process of radical racemization could be effectively combined with an ensuing step of bond formation in an enantioselective fashion, then it would give rise to deracemizative functionalization of racemic tertiary C-H bonds for stereoselective construction of chiral molecules bearing quaternary stereocenters. As a demonstration of this unique potential in radical chemistry, we herein report that metalloradical catalysis can be successfully applied to devise Co(II)-based catalytic system for enantioconvergent radical amination of racemic tertiary C(sp3)-H bonds. The key to the success of the radical process is the development of Co(II)-based metalloradical catalyst with fitting steric, electronic, and chiral environments of the D2-symmetric chiral amidoporphyrin as the supporting ligand. The existence of optimal reaction temperature is recognized as an important factor in the realization of the enantioconvergent radical process. Supported by an optimized chiral ligand, the Co(II)-based metalloradical system can effectively catalyze the enantioconvergent 1,6-amination of racemic tertiary C(sp3)-H bonds at the optimal temperature, affording chiral α-tertiary amines in excellent yields with high enantiocontrol of the newly created quaternary stereocenters. Systematic studies, including experiments utilizing optically active deuterium-labeled C-H substrates as a model system, shed light on the underlying mechanistic details of this new catalytic process for enantioconvergent radical C-H amination. The remarkable power to create quaternary stereocenters bearing multiple functionalities from ubiquitous C-H bonds, as showcased with stereoselective construction of bicyclic N-heterocycles, opens the door for future synthetic applications of this new radical technology.
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Affiliation(s)
- Kai Lang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Chaoqun Li
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Isaac Kim
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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Jin LM, Xu P, Xie J, Zhang XP. Enantioselective Intermolecular Radical C-H Amination. J Am Chem Soc 2020; 142:20828-20836. [PMID: 33238707 DOI: 10.1021/jacs.0c10415] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Radical reactions hold a number of inherent advantages in organic synthesis that may potentially impact the planning and practice for construction of organic molecules. However, the control of enantioselectivity in radical processes remains one of the longstanding challenges. While significant advances have recently been achieved in intramolecular radical reactions, the governing of asymmetric induction in intermolecular radical reactions still poses challenging issues. We herein report a catalytic approach that is highly effective for controlling enantioselectivity as well as reactivity of the intermolecular radical C-H amination of carboxylic acid esters with organic azides via Co(II)-based metalloradical catalysis (MRC). The key to the success lies in the catalyst development to maximize noncovalent attractive interactions through fine-tuning of the remote substituents of the D2-symmetric chiral amidoporphyrin ligand. This noncovalent interaction strategy presents a solution that may be generally applicable in controlling reactivity and enantioselectivity in intermolecular radical reactions. The Co(II)-catalyzed intermolecular C-H amination, which operates under mild conditions with the C-H substrate as the limiting reagent, exhibits a broad substrate scope with high chemoselectivity, providing effective access to valuable chiral amino acid derivatives with high enantioselectivities. Systematic mechanistic studies shed light into the working details of the underlying stepwise radical pathway for the Co(II)-based C-H amination.
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Affiliation(s)
- Li-Mei Jin
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Pan Xu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Jingjing Xie
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - X Peter Zhang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
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Martínez AR, Morales LP, Ojeda ED, Rodríguez MC, Rodríguez-García I. The Proven Versatility of Cp 2TiCl. J Org Chem 2020; 86:1311-1329. [PMID: 33147037 DOI: 10.1021/acs.joc.0c01233] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the last two decades, titanocene monochloride has been postulated as a monoelectronic transfer reagent capable of catalyzing an important variety of chemical transformations. In this Perspective, our contributions to this growing field of research are summarized and analyzed. Especially known have been our contributions in C-C bond formation reactions, hydrogen-atom transfer from water to radicals, and isomerization reactions, as well as the development of a catalytic cycle that has subsequently allowed the preparation of a great variety of natural terpenes. It is also worth mentioning our contribution in the postulation of this single-electron transfer agent (SET) as a new green catalyst with a broad range of applications in organic and organometallic chemistry. The most significant catalytic processes developed by other research groups are also briefly described, with special emphasis on the reaction mechanisms involved. Finally, a reflection is made on the future trends in the research of this SET, aimed at consolidating this chemical as a new green reagent that will be widely used in fine chemistry, green chemistry, and industrial chemical processes.
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Affiliation(s)
- Antonio Rosales Martínez
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
| | - Laura Pozo Morales
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
| | - Emilio Díaz Ojeda
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
| | - María Castro Rodríguez
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
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