1
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Badeji AA, Liu Y, Oladipo SD, Osinubi AD. Computational insights into the mechanisms and origins of switchable selectivity in gold(i)-catalyzed annulation of ynamides with isoxazoles via 6π-electrocyclizations of azaheptatrienyl cations. RSC Adv 2023; 13:18025-18037. [PMID: 37323448 PMCID: PMC10265590 DOI: 10.1039/d3ra02839a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 06/05/2023] [Indexed: 06/17/2023] Open
Abstract
Electrocyclizations of acyclic conjugated π-motifs have emerged as a versatile and effective strategy for accessing various ring systems with excellent functional group tolerability and controllable selectivity. Typically, the realization of 6π-electrocyclization of heptatrienyl cations to afford seven-membered motif has proven difficult due to the high-energy state of the cyclizing seven-membered intermediate. Instead, it undergoes the Nazarov cyclization, affording a five-membered pyrrole product. However, the incorporation of a Au(i)-catalyst, a nitrogen atom and tosylamide group in the heptatrienyl cations unexpectedly circumvented the aforementioned high energy state to afford a seven-membered azepine product via 6π-electrocyclization in the annulation of 3-en-1-ynamides with isoxazoles. Therefore, extensive computational studies were carried out to investigate the mechanism of Au(i)-catalyzed [4+3] annulation of 3-en-1-ynamides with dimethylisoxazoles to produce a seven-membered 4H-azepine via the 6π-electrocyclization of azaheptatrienyl cations. Computational results showed that after the formation of the key α-imino gold carbene intermediate, the annulation of 3-en-1-ynamides with dimethylisoxazole occurs via the unusual 6π-electrocyclization to afford a seven-membered 4H-azepine exclusively. However, the annulation of 3-cyclohexen-1-ynamides with dimethylisoxazole occurs via the commonly proposed aza-Nazarov cyclization pathway to majorly generate five-membered pyrrole derivatives. The results from the DFT predictive analysis revealed that the key factors responsible for the different chemo-, and regio-selectivities observed are the cooperating effect of the tosylamide group on C1, the uninterrupted π-conjugation pattern of the α-imino gold(i) carbene and the substitution pattern at the cyclization termini. The Au(i)-catalyst is believed to assist in the stabilization of the azaheptatrienyl cation.
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Affiliation(s)
| | - Yuan Liu
- School of Chemistry and Chemical Engineering, Nantong University 9 Seyuan Road Nantong 226019 China
| | - Segun D Oladipo
- Department of Chemical Sciences, Olabisi Onabanjo University 2002 Ago-Iwoye Nigeria
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2
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Almubayedh S, Green JR. Alkynedicobalt mediated vinylogous Nazarov reactions. Org Biomol Chem 2021; 20:1004-1007. [PMID: 34951440 DOI: 10.1039/d1ob02256c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The SnCl4 mediated reactions of cross conjugated aryl enynone-Co2(CO)6 and dienynone-Co2(CO)6 complexes afford benzocycloheptynone complexes or cycloheptenynone complexes in a thermal vinylogous Nazarov process. The rate of ring closure is strongly dependent on the ketone α-substituent.
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Affiliation(s)
- Somaiah Almubayedh
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, N9B 3P4, Canada.
| | - James R Green
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, N9B 3P4, Canada.
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3
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Kumar K, Kumar P, Singh B, Yadav S, Mishra UK, Ansari AJ, Ramasastry SSV. Hypothesis-Driven Palladium-Catalyzed Transformations for the Construction of New Molecular Architectures. CHEMICAL RECORD (NEW YORK, N.Y.) 2021; 21:3470-3482. [PMID: 33971073 DOI: 10.1002/tcr.202100095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/20/2021] [Accepted: 04/20/2021] [Indexed: 11/09/2022]
Abstract
The development of new synthetic protocols to access diverse molecular scaffolds from readily available starting compounds is of significance in both academia and industry. Towards this, the catalysis by transition metals has been employed as a powerful tool to access molecules with broad structural and functional diversity. An overview of the recent literature manifested the tremendous potential of transition metal-catalyzed processes in advancing organic synthesis in a new direction. This account compiles new conceptual advancements in the palladium-catalyzed Alder-ene type cycloisomerization reactions, C-H functionalizations, and one-pot multicatalytic processes, which have become essential tools to access new classes of molecules.
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Affiliation(s)
- Ketan Kumar
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Prashant Kumar
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Bara Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Sonu Yadav
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Uttam K Mishra
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Arshad J Ansari
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - S S V Ramasastry
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
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4
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Zhu X, Wang Z, Hou B, Zhang H, Deng C, Ye L. Zinc‐Catalyzed Asymmetric Formal [4+3] Annulation of Isoxazoles with Enynol Ethers by 6π Electrocyclization: Stereoselective Access to 2
H
‐Azepines. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201912534] [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]
Affiliation(s)
- Xin‐Qi Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Ze‐Shu Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Bo‐Shang Hou
- State Key Laboratory of Physical Chemistry of Solid Surfaces Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Hao‐Wen Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Chao Deng
- Jiangsu Key Laboratory of Pesticide Science and Department of Chemistry College of Sciences Nanjing Agricultural University Nanjing 210095 China
| | - Long‐Wu Ye
- State Key Laboratory of Physical Chemistry of Solid Surfaces Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
- State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 China
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5
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Zhu XQ, Wang ZS, Hou BS, Zhang HW, Deng C, Ye LW. Zinc-Catalyzed Asymmetric Formal [4+3] Annulation of Isoxazoles with Enynol Ethers by 6π Electrocyclization: Stereoselective Access to 2H-Azepines. Angew Chem Int Ed Engl 2019; 59:1666-1673. [PMID: 31724314 DOI: 10.1002/anie.201912534] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/31/2019] [Indexed: 12/17/2022]
Abstract
6π electrocyclization has attracted interest in organic synthesis because of its high stereospecificity and atom economy in the construction of versatile 5-7-membered cycles. However, examples of asymmetric 6π electrocyclization are quite scarce, and have to rely on the use of chiral organocatalysts, and been limited to pentadienyl-anion- and triene-type 6π electrocyclizations. Described herein is a zinc-catalyzed formal [4+3] annulation of isoxazoles with 3-en-1-ynol ethers via 6π electrocyclization, leading to the site-selective synthesis of functionalized 2H-azepines and 4H-azepines in good to excellent yields with broad substrate scope. Moreover, this strategy has also been used to produce chiral 2H-azepines with high enantioselectivities (up to 97:3 e.r.). This protocol not only is the first asymmetric heptatrienyl-cation-type 6π electrocyclization, but also is the first asymmetric reaction of isoxazoles with alkynes and the first asymmetric catalysis based on ynol ethers.
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Affiliation(s)
- Xin-Qi Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Ze-Shu Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Bo-Shang Hou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Hao-Wen Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Chao Deng
- Jiangsu Key Laboratory of Pesticide Science and Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Long-Wu Ye
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.,State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
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6
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Holt C, Alachouzos G, Frontier AJ. Leveraging the Halo-Nazarov Cyclization for the Chemodivergent Assembly of Functionalized Haloindenes and Indanones. J Am Chem Soc 2019; 141:5461-5469. [DOI: 10.1021/jacs.9b00198] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Connor Holt
- Department of Chemistry, University of Rochester, 414 Hutchison Hall, 100 Trustee Road, Rochester, New York 14627-0216, United States
| | - Georgios Alachouzos
- Department of Chemistry, University of Rochester, 414 Hutchison Hall, 100 Trustee Road, Rochester, New York 14627-0216, United States
| | - Alison J. Frontier
- Department of Chemistry, University of Rochester, 414 Hutchison Hall, 100 Trustee Road, Rochester, New York 14627-0216, United States
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7
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Riveira MJ, Marcarino MO, La-Venia A. Multicomponent Domino Synthesis of Cyclopenta[b]furan-2-ones. Org Lett 2018; 20:4000-4004. [DOI: 10.1021/acs.orglett.8b01567] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Martín J. Riveira
- Instituto de Química Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario-CONICET, Suipacha 531, S2002LRK Rosario, Argentina
| | - Maribel O. Marcarino
- Instituto de Química Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario-CONICET, Suipacha 531, S2002LRK Rosario, Argentina
| | - Agustina La-Venia
- Instituto de Química Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario-CONICET, Suipacha 531, S2002LRK Rosario, Argentina
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8
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Giri SS, Liu RS. Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations. Chem Sci 2018; 9:2991-2995. [PMID: 29732082 PMCID: PMC5915799 DOI: 10.1039/c8sc00232k] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 02/18/2018] [Indexed: 12/22/2022] Open
Abstract
New gold-catalyzed [4+3]-annulations of 3-en-1-ynamides with isoxazoles afford 4H-azepines efficiently; this process involves 6π electrocyclizations of gold-stabilized 3-azaheptatrienyl cations. In the presence of Zn(OTf)2, the resulting 4H-azepines undergo skeletal rearrangement to furnish substituted pyridine derivatives. We subsequently develop new catalytic [4+2]-annulations between the same 3-en-1-ynamides and isoxazoles to deliver substituted pyridine products using Au(i)/Zn(ii) catalysts. This work reports the first success of the 6π electrocyclizations of heptatrienyl cations that are unprecedented in literature reports.
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Affiliation(s)
- Sovan Sundar Giri
- Department of Chemistry , National Tsing-Hua University , Hsinchu , Taiwan , Republic of China .
| | - Rai-Shung Liu
- Department of Chemistry , National Tsing-Hua University , Hsinchu , Taiwan , Republic of China .
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9
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Bankar SK, Singh B, Tung P, Ramasastry SSV. Palladium-Catalyzed Intramolecular Trost-Oppolzer-Type Alder-Ene Reaction of Dienyl Acetates to Cyclopentadienes. Angew Chem Int Ed Engl 2018; 57:1678-1682. [PMID: 29219255 DOI: 10.1002/anie.201711797] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Indexed: 01/17/2023]
Abstract
A new approach to the synthesis of highly substituted cyclopentadienes, indenes, and cyclopentene-fused heteroarenes by means of the Pd-catalyzed Trost-Oppolzer-type intramolecular Alder-ene reaction of 2,4-pentadienyl acetates is described. This unprecedented transformation combines the electrophilic features of the Tsuji-Trost reaction with the nucleophilic features of the Alder-ene reaction. The overall outcome can be perceived as a hitherto unknown "acid-free" iso-Nazarov-type cyclization. The versatility of this strategy was further demonstrated by the formal synthesis of paucifloral F, a resveratrol-based natural product.
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Affiliation(s)
- Siddheshwar K Bankar
- Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Bara Singh
- Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Pinku Tung
- Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - S S V Ramasastry
- Organic Synthesis and Catalysis Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
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10
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Bankar SK, Singh B, Tung P, Ramasastry SSV. Palladium-Catalyzed Intramolecular Trost-Oppolzer-Type Alder-Ene Reaction of Dienyl Acetates to Cyclopentadienes. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201711797] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Siddheshwar K. Bankar
- Organic Synthesis and Catalysis Lab; Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Mohali; Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO Punjab 140306 India
| | - Bara Singh
- Organic Synthesis and Catalysis Lab; Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Mohali; Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO Punjab 140306 India
| | - Pinku Tung
- Organic Synthesis and Catalysis Lab; Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Mohali; Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO Punjab 140306 India
| | - S. S. V. Ramasastry
- Organic Synthesis and Catalysis Lab; Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Mohali; Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO Punjab 140306 India
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11
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Pusch S, Tröster A, Lefrancois D, Farahani P, Dreuw A, Bach T, Opatz T. Mechanism and cis/trans Selectivity of Vinylogous Nazarov-type [6π] Photocyclizations. J Org Chem 2018; 83:964-972. [DOI: 10.1021/acs.joc.7b02982] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stefan Pusch
- Institute
of Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10−14, 55128 Mainz, Germany
| | - Andreas Tröster
- Department
Chemie and Catalysis Research Center (CRC), Technical University Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Daniel Lefrancois
- Interdisciplinary
Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer
Feld 205A, 69120 Heidelberg, Germany
| | - Pooria Farahani
- Instituto
de Química, Departamento de Química Fundamental, Universidade de São Paulo, C. P. 05508-000, São Paulo, SP Brazil
| | - Andreas Dreuw
- Interdisciplinary
Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer
Feld 205A, 69120 Heidelberg, Germany
| | - Thorsten Bach
- Department
Chemie and Catalysis Research Center (CRC), Technical University Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Till Opatz
- Institute
of Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10−14, 55128 Mainz, Germany
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12
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Villar López R, Faza ON, Silva López C. Dynamic Effects Responsible for High Selectivity in a [3,3] Sigmatropic Rearrangement Featuring a Bispericyclic Transition State. J Org Chem 2017; 82:4758-4765. [DOI: 10.1021/acs.joc.7b00425] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Roberto Villar López
- Departamento de Química
Orgánica, Universidade de Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain
| | - Olalla Nieto Faza
- Departamento de Química
Orgánica, Universidade de Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain
| | - Carlos Silva López
- Departamento de Química
Orgánica, Universidade de Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Spain
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13
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Abstract
The acid-promoted cycloisomerization of conjugated dienals and linearly-conjugated dienones for the synthesis of five-membered ring systems is reviewed.
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Affiliation(s)
- Martín J. Riveira
- Departamento de Química Orgánica
- Instituto de Química Rosario (CONICET – UNR)
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- Suipacha 531
| | - Lucía A. Marsili
- Departamento de Química Orgánica
- Instituto de Química Rosario (CONICET – UNR)
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- Suipacha 531
| | - Mirta P. Mischne
- Departamento de Química Orgánica
- Instituto de Química Rosario (CONICET – UNR)
- Facultad de Ciencias Bioquímicas y Farmacéuticas
- Universidad Nacional de Rosario
- Suipacha 531
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14
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Abstract
The first examples of a photochemically induced vinylogous Nazarov-type cyclization forming a cycloheptadienone core are described. The reaction can be included in a three-step cascade consisting of a photochemical isoxazole-azirine ring contraction, cobalt(II)-catalyzed ring expansion, and the photochemical cyclization. Furthermore, the first representative of the hitherto unknown 1-azatricyclo[2.2.0.0(2,6)]hexanes has been identified as a side product of the azirine formation.
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Affiliation(s)
- Stefan Pusch
- Institute of Organic Chemistry, Johannes Gutenberg University , Duesbergweg 10-14, 55128 Mainz, Germany
| | - Dieter Schollmeyer
- Institute of Organic Chemistry, Johannes Gutenberg University , Duesbergweg 10-14, 55128 Mainz, Germany
| | - Till Opatz
- Institute of Organic Chemistry, Johannes Gutenberg University , Duesbergweg 10-14, 55128 Mainz, Germany
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15
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López RV, Faza ON, López CS. Conformational control allows for [3,3]-sigmatropic rearrangements to proceed with torquoselectivity. RSC Adv 2016. [DOI: 10.1039/c6ra10789c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Sigmatropic reactions can proceed through torquoselective-like mechanisms with approppriate structure design.
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16
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Riveira MJ, Mischne MP. An Interrupted Vinylogous Iso-Nazarov Reaction: Cycloisomerization of Conjugated Trienones to Cyclopenta[b]furan Derivatives. J Org Chem 2014; 79:8244-54. [DOI: 10.1021/jo501453b] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Martín J. Riveira
- Instituto
de Química
Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Santa Fe, Argentina
| | - Mirta P. Mischne
- Instituto
de Química
Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Santa Fe, Argentina
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17
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Pérez AG, Álvarez R, de Lera ÁR. Characterization of pericyclic steps in the mechanisms of Gold(I) catalyzed rearrangement of alkynes. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2012. [DOI: 10.1002/wcms.1126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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González-Pérez AB, Vaz B, Nieto Faza O, de Lera AR. Mechanistic and sterochemical insights on the Pt-catalyzed rearrangement of oxiranylpropargylic esters to cyclopentenones. J Org Chem 2012; 77:8733-43. [PMID: 22963654 DOI: 10.1021/jo301651r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A mechanism for the rearrangement of oxiranylpropargylic esters to cyclopentenones catalyzed by PtCl(2) is proposed based on DFT calculations (M06/6-31++G(d,p)). Although the basic steps are coincidental with those proposed by Sarpong et al., who characterized a 2H-pyran as intermediate, calculations have revealed other intricate details of this complex rearrangement. The 2H-pyran is proposed to result from the ring-opening of a bicyclic oxonium ion that follows the nucleophilic capture by the epoxide of a platinum carbene generated by an initial Pt-mediated 1,2-propargylic rearrangement. The key steps in the evolution of this system are the electrocyclic ring-opening of the 2H-pyran to a α-methoxycarbonyl dienone and an iso-Nazarov ring closure. Prior to those, changes in hapticity and in the conformation of the dienone are required in order to produce the helical conformation needed to generate a single diastereomer of the cyclopentenone product obtained experimentally. The metal is needed well beyond the first step of the mechanism, and both electrocyclic reactions are favored by coordination to the metal when compared to their uncomplexed counterparts. Moreover, we have experimentally demonstrated that the rearrangement is stereoconvergent, a feature that is traced back to the initial configuration of the epoxide, which determines the somewhat counterthermodynamic placement of the metal syn to the methyl group of the stereogenic center in the 2H-pyran intermediate. Finally, starting from enantiopure oxiranylpropargylic ester 13, a racemate of cyclopentenone (R*,S*)-16 was obtained. Thus, the sequence does not proceed with memory of chirality, and the absolute stereochemical information is already lost at the stage of the 2H-pyran 14.
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Affiliation(s)
- Adán B González-Pérez
- Departamento de Química Orgánica, Facultade de Química, Universidade de Vigo, 36310 Vigo, Spain
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19
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Varea T, Alcalde A, López de Dicastillo C, Ramírez de Arellano C, Cossío FP, Asensio G. Selective "one-pot" synthesis of functionalized cyclopentenones. J Org Chem 2012; 77:6327-31. [PMID: 22720875 DOI: 10.1021/jo300806y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Double addition (1,2-1,4) of vinyl magnesium bromide to squaric acid derivatives allows the preparation of polyoxygenated cyclopentenones (8) in a "one-pot" procedure. The reaction occurs through the intermediate formation of octatetraenes (6). Protonation of this latter intermediate at -78 °C with TFE occurs selectively at the vinyl CH(2) closer to the metallic centers. DFT studies of the cyclization step justify the observed diastereoselectivity.
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Affiliation(s)
- Teresa Varea
- Departamento de Química Orgánica, Universidad de Valencia, 46100 Burjassot, Valencia, Spain.
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Li WDZ, Duo WG, Zhuang CH. Concise Total Synthesis of (±)-Cephalotaxine via a Transannulation Strategy: Development of a Facile Reductive oxy-Nazarov Cyclization. Org Lett 2011; 13:3538-41. [DOI: 10.1021/ol201390r] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wei-Dong Z. Li
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Wei-Guo Duo
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Cheng-Han Zhuang
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, P. R. China
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21
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Faza ON, López CS, de Lera AR. On the Memory of Chirality in Gold(I)-Catalyzed Intramolecular Carboalkoxylation of Alkynes. J Org Chem 2011; 76:3791-6. [DOI: 10.1021/jo200090j] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Olalla Nieto Faza
- Departamento de Química Orgánica, Facultade de Ciencias, Universidade de Vigo, Campus As Lagoas 32004, Ourense, Spain
| | - Carlos Silva López
- Departamento de Química Orgánica, Facultade de Química, Universidade de Vigo, As Lagoas/Marcosende 36310, Vigo, Spain
| | - Angel R. de Lera
- Departamento de Química Orgánica, Facultade de Química, Universidade de Vigo, As Lagoas/Marcosende 36310, Vigo, Spain
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22
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Faza ON, de Lera AR. DFT-Based Mechanistic Insights into Noble Metal-Catalyzed Rearrangement of Propargylic Derivatives: Chirality Transfer Processes. Top Curr Chem (Cham) 2011; 302:81-130. [DOI: 10.1007/128_2010_117] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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23
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Sanz R, Miguel D, Gohain M, García-García P, Fernández-Rodríguez M, González-Pérez A, Nieto-Faza O, de Lera Á, Rodríguez F. Synthesis of Diverse Indole-Containing Scaffolds by Gold(I)-Catalyzed Tandem Reactions of 3-Propargylindoles Initiated by 1,2-Indole Migrations: Scope and Computational Studies. Chemistry 2010; 16:9818-28. [DOI: 10.1002/chem.201001162] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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