1
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Yang Z, Zalessky I, Epton RG, Whitwood AC, Lynam JM, Unsworth WP. Ring Expansion Strategies for the Synthesis of Medium Sized Ring and Macrocyclic Sulfonamides. Angew Chem Int Ed Engl 2023; 62:e202217178. [PMID: 36716014 DOI: 10.1002/anie.202217178] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/16/2023] [Accepted: 01/30/2023] [Indexed: 01/31/2023]
Abstract
Two new ring expansion strategies are reported for the synthesis of medium sized ring and macrocyclic sulfonamides. Both methods can be performed without using classical protecting groups, with the key ring expansion step initiated by nitro reduction and amine conjugate addition respectively. Each method can be used to make diversely functionalised cyclic sulfonamides in good to excellent yields, in a range of ring sizes. The ring size dependency of the synthetic reactions is in good agreement with the outcomes modelled by Density Functional Theory calculations.
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Affiliation(s)
- Zhongzhen Yang
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Illya Zalessky
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Ryan G Epton
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | | | - Jason M Lynam
- Department of Chemistry, University of York, York, YO10 5DD, UK
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2
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Xu H, Ma S. Palladium-Catalyzed [6+2] Double Allene Annulation for Benzazocines Synthesis. Angew Chem Int Ed Engl 2023; 62:e202213676. [PMID: 36372784 DOI: 10.1002/anie.202213676] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/07/2022] [Accepted: 11/11/2022] [Indexed: 11/15/2022]
Abstract
An efficient double allene protocol for the formation of benzazocines has been developed. The reaction constitutes a highly regioselective palladium-catalyzed formal [6+2] annulation of allenyl benzoxazinanones with terminal allenes forming the challenging 8-membered cycles. Decent yields and excellent regioselectivity have been observed under mild conditions with a remarkable Z-stereoselectivity for the exo-cyclic C=C bonds. The synthetic potentials of benzazocine products have been demonstrated.
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Affiliation(s)
- Haibo Xu
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Shengming Ma
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, P. R. China.,Research Center for Molecular Recognition and Synthesis, Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, P. R. China
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3
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Titov AA, Purgatorio R, Obydennik AY, Listratova AV, Borisova TN, de Candia M, Catto M, Altomare CD, Varlamov AV, Voskressensky LG. Synthesis of Isomeric 3-Benzazecines Decorated with Endocyclic Allene Moiety and Exocyclic Conjugated Double Bond and Evaluation of Their Anticholinesterase Activity. Molecules 2022; 27:molecules27196276. [PMID: 36234811 PMCID: PMC9571408 DOI: 10.3390/molecules27196276] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/17/2022] [Accepted: 09/19/2022] [Indexed: 11/29/2022] Open
Abstract
Transformations of 1-methoxymethylethynyl substituted isoquinolines triggered by terminal alkynes in alcohols were studied and new 3-benzazecine-containing compounds synthesized, such as 6-methoxymethyl-3-benzazecines incorporating an endocyclic C6–C8 allene fragment and the -ylidene derivatives 6-methoxymethylene-3-benzazecines. The reaction mechanisms were investigated and a preliminary in vitro screening of their potential inhibitory activities against human acetyl- and butyrylcholinesterases (AChE and BChE) and monoamine oxidases A and B (MAO-A and MAO-B) showed that the allene compounds were more potent than the corresponding -ylidene ones as selective AChE inhibitors. Among the allenes, 3e (R3 = CH2OMe) was found to be a competitive AChE inhibitor with a low micromolar inhibition constant value (Ki = 4.9 μM), equipotent with the corresponding 6-phenyl derivative 3n (R3 = Ph, Ki = 4.5 μM), but 90-fold more water-soluble.
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Affiliation(s)
- Alexander A. Titov
- Organic Chemistry Department, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia
| | - Rosa Purgatorio
- Department of Pharmacy-Pharmaceutical Sciences, University of Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Arina Y. Obydennik
- Organic Chemistry Department, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia
| | - Anna V. Listratova
- Organic Chemistry Department, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia
| | - Tatiana N. Borisova
- Organic Chemistry Department, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia
| | - Modesto de Candia
- Department of Pharmacy-Pharmaceutical Sciences, University of Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Marco Catto
- Department of Pharmacy-Pharmaceutical Sciences, University of Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Cosimo D. Altomare
- Department of Pharmacy-Pharmaceutical Sciences, University of Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
- Correspondence: ; Tel.: +39-080-5442781
| | - Alexey V. Varlamov
- Organic Chemistry Department, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia
| | - Leonid G. Voskressensky
- Organic Chemistry Department, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia
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4
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Rao MS, Hussain S. DABCO-mediated decarboxylative cyclization of isatoic anhydride with aroyl/heteroaroyl/alkoylacetonitriles under microwave conditions: Strategy for the synthesis of substituted 4-quinolones. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Abrams R, Jesani MH, Browning A, Clayden J. Triarylmethanes and their Medium-Ring Analogues by Unactivated Truce-Smiles Rearrangement of Benzanilides. Angew Chem Int Ed Engl 2021; 60:11272-11277. [PMID: 33830592 PMCID: PMC8252078 DOI: 10.1002/anie.202102192] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/01/2021] [Indexed: 12/17/2022]
Abstract
Intramolecular nucleophilic aromatic substitution (Truce–Smiles rearrangement) of the anions of 2‐benzyl benzanilides leads to triarylmethanes in an operationally simple manner. The reaction succeeds even without electronic activation of the ring that plays the role of electrophile in the SNAr reaction, being accelerated instead by the preferred conformation imposed by the tertiary amide tether. The amide substituent of the product may be removed or transformed into alternative functional groups. A ring‐expanding variant (n to n+4) of the reaction provided a route to doubly benzo‐fused medium ring lactams of 10 or 11 members. Hammett analysis returned a ρ value consistent with the operation of a partially concerted reaction mechanism.
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Affiliation(s)
- Roman Abrams
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Mehul H Jesani
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Alex Browning
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Jonathan Clayden
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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6
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Yang G, Ke Y, Zhao Y. Stereoselective Access to Polyfunctionalized Nine‐Membered Heterocycles by Sequential Gold and Palladium Catalysis. Angew Chem Int Ed Engl 2021; 60:12775-12780. [DOI: 10.1002/anie.202102061] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/28/2021] [Indexed: 11/05/2022]
Affiliation(s)
- Guoqiang Yang
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
| | - Ya‐Ming Ke
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
| | - Yu Zhao
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
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7
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Yang G, Ke Y, Zhao Y. Stereoselective Access to Polyfunctionalized Nine‐Membered Heterocycles by Sequential Gold and Palladium Catalysis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102061] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Guoqiang Yang
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
| | - Ya‐Ming Ke
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
| | - Yu Zhao
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
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8
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Abrams R, Jesani MH, Browning A, Clayden J. Triarylmethanes and their Medium‐Ring Analogues by Unactivated Truce–Smiles Rearrangement of Benzanilides. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Roman Abrams
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Mehul H. Jesani
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Alex Browning
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
| | - Jonathan Clayden
- School of Chemistry University of Bristol, Cantock's Close Bristol BS8 1TS UK
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9
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Qiao J, Zhao W, Liang Y, Yao ZJ, Wang S. Diastereoselective Access to Tetracyclic Eight-Membered Lactams through a Dearomative Heck Reaction and an Alkylative Ring-Opening Driven by Photoexcited Spiroindolines. Chemistry 2021; 27:6308-6314. [PMID: 33506517 DOI: 10.1002/chem.202005369] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/25/2021] [Indexed: 11/05/2022]
Abstract
An external-photocatalyst-free, light-driven alkylative ring-opening of stable spiroindolines was developed to construct indolo- and benzoannulated eight-membered lactams. The spiroindolines were prepared from tetrahydro-β-carbolines by a dearomative Heck reaction. Mechanistic experimental studies on the alkylative ring opening suggested that a photoredox pathway was involved, in which the spiroindoline performed as both reagent and photosensitizer. DFT calculations showed that the radical addition toward a cyclic alkene was the key to the diastereoselective formation of tetracyclic medium-sized lactams.
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Affiliation(s)
- Jianhui Qiao
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratoryof Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Wenxuan Zhao
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratoryof Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Yong Liang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratoryof Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Zhu-Jun Yao
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratoryof Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Shaozhong Wang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratoryof Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
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10
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Lawer A, Epton RG, Stephens TC, Palate KY, Lodi M, Marotte E, Lamb KJ, Sangha JK, Lynam JM, Unsworth WP. Evaluating the Viability of Successive Ring-Expansions Based on Amino Acid and Hydroxyacid Side-Chain Insertion. Chemistry 2020; 26:12674-12683. [PMID: 32432817 PMCID: PMC7589337 DOI: 10.1002/chem.202002164] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Indexed: 01/20/2023]
Abstract
The outcome of ring-expansion reactions based on amino/hydroxyacid side-chain insertion is strongly dependent on ring size. This manuscript, which builds upon our previous work on Successive Ring Expansion (SuRE) methods, details efforts to better define the scope and limitations of these reactions on lactam and β-ketoester ring systems with respect to ring size and additional functionality. The synthetic results provide clear guidelines as to which substrate classes are more likely to be successful and are supported by computational results, using a density functional theory (DFT) approach. Calculating the relative Gibbs free energies of the three isomeric species that are formed reversibly during ring expansion enables the viability of new synthetic reactions to be correctly predicted in most cases. The new synthetic and computational results are expected to support the design of new lactam- and β-ketoester-based ring-expansion reactions.
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Affiliation(s)
- Aggie Lawer
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | - Ryan G. Epton
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | | | | | - Mahendar Lodi
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | - Emilie Marotte
- ENSICAEN6 Boulevard Maréchal Juin, CS 4505314050Caen Cedex 04France
| | - Katie J. Lamb
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
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11
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Zhang Z, Qin Z, Chang W, Li J, Fan R, Wu X, Guo R, Xie X, Zhou L. Nickel‐Catalyzed Decarboxylative Cyclization of Isatoic Anhydrides with Carbodiimides: Synthesis of 2,3‐Dihydroquinazolin‐4(1
H
)‐ones. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000047] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Zhen Zhang
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
| | - Ziqiang Qin
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
| | - Wenxu Chang
- Department of Applied ChemistryChina Agricultural University Beijing 100193 People's Republic of China
| | - Jiazhu Li
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
| | - Ruoqian Fan
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
| | - Xing Wu
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
| | - Rongrong Guo
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
| | - Xiangqi Xie
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
| | - Lanxin Zhou
- College of Chemistry and Chemical EngineeringYantai University Yantai 264005, P. R. of People's Republic of China
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12
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Rohrbach S, Smith AJ, Pang JH, Poole DL, Tuttle T, Chiba S, Murphy JA. Concerted Nucleophilic Aromatic Substitution Reactions. Angew Chem Int Ed Engl 2019; 58:16368-16388. [PMID: 30990931 PMCID: PMC6899550 DOI: 10.1002/anie.201902216] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/11/2019] [Indexed: 12/31/2022]
Abstract
Recent developments in experimental and computational chemistry have identified a rapidly growing class of nucleophilic aromatic substitutions that proceed by concerted (cSN Ar) rather than classical, two-step, SN Ar mechanisms. Whereas traditional SN Ar reactions require substantial activation of the aromatic ring by electron-withdrawing substituents, such activating groups are not mandatory in the concerted pathways.
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Affiliation(s)
- Simon Rohrbach
- Department of Pure and Applied ChemistryUniversity of Strathclyde295 Cathedral StreetGlasgowG1 1XLUK
| | - Andrew J. Smith
- Department of Pure and Applied ChemistryUniversity of Strathclyde295 Cathedral StreetGlasgowG1 1XLUK
| | - Jia Hao Pang
- Division of Chemistry and Biological ChemistrySchool of Physical and Mathematical SciencesNanyang Technological UniversitySingapore637371Singapore
| | - Darren L. Poole
- GlaxoSmithKline Medicines Research CentreGunnels Wood RoadStevenageSG1 2NYUK
| | - Tell Tuttle
- Department of Pure and Applied ChemistryUniversity of Strathclyde295 Cathedral StreetGlasgowG1 1XLUK
| | - Shunsuke Chiba
- Division of Chemistry and Biological ChemistrySchool of Physical and Mathematical SciencesNanyang Technological UniversitySingapore637371Singapore
| | - John A. Murphy
- Department of Pure and Applied ChemistryUniversity of Strathclyde295 Cathedral StreetGlasgowG1 1XLUK
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13
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Lawer A, Rossi‐Ashton JA, Stephens TC, Challis BJ, Epton RG, Lynam JM, Unsworth WP. Internal Nucleophilic Catalyst Mediated Cyclisation/Ring Expansion Cascades for the Synthesis of Medium‐Sized Lactones and Lactams. Angew Chem Int Ed Engl 2019; 58:13942-13947. [DOI: 10.1002/anie.201907206] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/23/2019] [Indexed: 12/12/2022]
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14
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Rohrbach S, Smith AJ, Pang JH, Poole DL, Tuttle T, Chiba S, Murphy JA. Konzertierte nukleophile aromatische Substitutionen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902216] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Simon Rohrbach
- Department of Pure and Applied ChemistryUniversity of Strathclyde 295 Cathedral Street Glasgow G1 1XL Großbritannien
| | - Andrew J. Smith
- Department of Pure and Applied ChemistryUniversity of Strathclyde 295 Cathedral Street Glasgow G1 1XL Großbritannien
| | - Jia Hao Pang
- Division of Chemistry and Biological ChemistrySchool of Physical and Mathematical SciencesNanyang Technological University Singapore 637371 Singapur
| | - Darren L. Poole
- GlaxoSmithKline Medicines Research Centre Gunnels Wood Road Stevenage SG1 2NY Großbritannien
| | - Tell Tuttle
- Department of Pure and Applied ChemistryUniversity of Strathclyde 295 Cathedral Street Glasgow G1 1XL Großbritannien
| | - Shunsuke Chiba
- Division of Chemistry and Biological ChemistrySchool of Physical and Mathematical SciencesNanyang Technological University Singapore 637371 Singapur
| | - John A. Murphy
- Department of Pure and Applied ChemistryUniversity of Strathclyde 295 Cathedral Street Glasgow G1 1XL Großbritannien
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15
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Lawer A, Rossi‐Ashton JA, Stephens TC, Challis BJ, Epton RG, Lynam JM, Unsworth WP. Internal Nucleophilic Catalyst Mediated Cyclisation/Ring Expansion Cascades for the Synthesis of Medium‐Sized Lactones and Lactams. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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16
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Wu A, Feng Q, Sung HHY, Williams ID, Sun J. Synthesis of Eight‐Membered Lactams through Formal [6+2] Cyclization of Siloxy Alkynes and Vinylazetidines. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902866] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- An Wu
- Department of ChemistryThe Hong Kong University of Science and Technology Clear Water Bay Kowloon, Hong Kong SAR China
| | - Qiang Feng
- Department of ChemistryThe Hong Kong University of Science and Technology Clear Water Bay Kowloon, Hong Kong SAR China
| | - Herman H. Y. Sung
- Department of ChemistryThe Hong Kong University of Science and Technology Clear Water Bay Kowloon, Hong Kong SAR China
| | - Ian D. Williams
- Department of ChemistryThe Hong Kong University of Science and Technology Clear Water Bay Kowloon, Hong Kong SAR China
| | - Jianwei Sun
- Department of ChemistryThe Hong Kong University of Science and Technology Clear Water Bay Kowloon, Hong Kong SAR China
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17
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Wu A, Feng Q, Sung HHY, Williams ID, Sun J. Synthesis of Eight-Membered Lactams through Formal [6+2] Cyclization of Siloxy Alkynes and Vinylazetidines. Angew Chem Int Ed Engl 2019; 58:6776-6780. [PMID: 30888103 DOI: 10.1002/anie.201902866] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Indexed: 12/31/2022]
Abstract
A new approach for the efficient synthesis of eight-membered lactams through formal [6+2] cyclization of siloxy alkynes and vinylazetidines has been developed. Evidence from a chirality transfer experiment suggests that the reaction proceeds via a [3,3]-sigmatropic rearrangement from a ketene intermediate. This insight led to the development of alternative conditions and use of acyl chlorides as ketene precursors for the [6+2] reaction with vinylazetidines.
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Affiliation(s)
- An Wu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Qiang Feng
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Herman H Y Sung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Ian D Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jianwei Sun
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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18
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Nikitin K, O'Gara R. Mechanisms and Beyond: Elucidation of Fluxional Dynamics by Exchange NMR Spectroscopy. Chemistry 2019; 25:4551-4589. [PMID: 30421834 DOI: 10.1002/chem.201804123] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Indexed: 12/31/2022]
Abstract
Detailed mechanistic information is crucial to our understanding of reaction pathways and selectivity. Dynamic exchange NMR techniques, in particular 2D exchange spectroscopy (EXSY) and its modifications, provide indispensable intricate information on the mechanisms of organic and inorganic reactions and other phenomena, for example, the dynamics of interfacial processes. In this Review, key results from exchange NMR studies of small molecules over the last few decades are systemised and discussed. After a brief introduction to the theory, the key types of dynamic processes are identified and fundamental examples given of intra- and intermolecular reactions, which, in turn, could involve, or not, bond-making and bond-breaking events. Following that logic, internal molecular rotation, intramolecular stereomutation and molecular recognition will first be considered because they do not typically involve bond breaking. Then, rearrangements, substitution-type reactions, cyclisations, additions and other processes affecting chemical bonds will be discussed. Finally, interfacial molecular dynamics and unexpected combinations of different types of fluxional processes will also be highlighted. How exchange NMR spectroscopy helps to identify conformational changes, coordination and molecular recognition processes as well as quantify reaction energy barriers and extract detailed mechanistic information by using reaction rate theory in conjunction with computational techniques will be shown.
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Affiliation(s)
- Kirill Nikitin
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
| | - Ryan O'Gara
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
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19
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Liu Z, Hu X. Palladium‐Catalyzed Propargylic [n+2] Cycloaddition: An Efficient Strategy for Construction of Benzo‐Fused Medium‐Sized Heterocycles. Adv Synth Catal 2018. [DOI: 10.1002/adsc.201801359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Zhen‐Ting Liu
- Dalian Institute of Chemical PhysicsChinese Academy of Sciences 457 Zhongshan Road Dalian 116023 People's Republic of China
- University of Chinese Academy of Sciences Beijing 100049 People's Republic of China
| | - Xiang‐Ping Hu
- Dalian Institute of Chemical PhysicsChinese Academy of Sciences 457 Zhongshan Road Dalian 116023 People's Republic of China
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20
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Zhou Y, Wei YL, Rodriguez J, Coquerel Y. Enantioselective Organocatalytic Four-Atom Ring Expansion of Cyclobutanones: Synthesis of Benzazocinones. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201810184] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Yirong Zhou
- Aix Marseille Université; CNRS; Centrale Marseille, ISM2; 13397 Marseille France
- Key Laboratory of Functional Small Organic Molecules Ministry of Education; Jiangxi Normal University; 330022 Nanchang China
| | - Yun-Long Wei
- Aix Marseille Université; CNRS; Centrale Marseille, ISM2; 13397 Marseille France
| | - Jean Rodriguez
- Aix Marseille Université; CNRS; Centrale Marseille, ISM2; 13397 Marseille France
| | - Yoann Coquerel
- Aix Marseille Université; CNRS; Centrale Marseille, ISM2; 13397 Marseille France
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21
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Zhou Y, Wei YL, Rodriguez J, Coquerel Y. Enantioselective Organocatalytic Four-Atom Ring Expansion of Cyclobutanones: Synthesis of Benzazocinones. Angew Chem Int Ed Engl 2018; 58:456-460. [PMID: 30398303 DOI: 10.1002/anie.201810184] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/15/2018] [Indexed: 01/04/2023]
Abstract
An enantioselective Michael addition- four-atom ring expansion cascade reaction involving cyclobutanones activated by a N-aryl secondary amide group and ortho-amino nitrostyrenes has been developed for the preparation of functionalized eight-membered benzolactams using bifunctional aminocatalysts. Taking advantage of the secondary amide activating group, the eight-membered cyclic products could be further rearranged into their six-membered isomers having a glutarimide core under base catalysis conditions without erosion of optical purity, featuring an overall ring expansion- ring contraction strategy.
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Affiliation(s)
- Yirong Zhou
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France.,Key Laboratory of Functional Small Organic Molecules Ministry of Education, Jiangxi Normal University, 330022, Nanchang, China
| | - Yun-Long Wei
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France
| | - Jean Rodriguez
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France
| | - Yoann Coquerel
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France
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22
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Wang YN, Yang LC, Rong ZQ, Liu TL, Liu R, Zhao Y. Pd-Catalyzed Enantioselective [6+4] Cycloaddition of Vinyl Oxetanes with Azadienes to Access Ten-Membered Heterocycles. Angew Chem Int Ed Engl 2018; 57:1596-1600. [DOI: 10.1002/anie.201711648] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 12/16/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Ya-Nong Wang
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Li-Cheng Yang
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Zi-Qiang Rong
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Tang-Lin Liu
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Ruoyang Liu
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Yu Zhao
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
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23
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Wang YN, Yang LC, Rong ZQ, Liu TL, Liu R, Zhao Y. Pd-Catalyzed Enantioselective [6+4] Cycloaddition of Vinyl Oxetanes with Azadienes to Access Ten-Membered Heterocycles. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201711648] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Ya-Nong Wang
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Li-Cheng Yang
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Zi-Qiang Rong
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Tang-Lin Liu
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Ruoyang Liu
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
| | - Yu Zhao
- Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
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