1
|
Chen T, Gong F, Nagaraju S, Liu J, Yang S, Chen X, Fang X. Oxa-Nazarov Cyclization-Michael Addition Sequence for the Rapid Construction of Dihydrofuranones. Org Lett 2022; 24:8837-8842. [PMID: 36417711 DOI: 10.1021/acs.orglett.2c03601] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The Nazarov cyclization has been established as a powerful tool in constructing cyclopentenone skeletons. In sharp contrast, oxa-Nazarov cyclization that affords dihydrofuranones, a new type of product, has been less explored. In this work, we report the I2-catalyzed oxa-Nazarov cyclization-Michael addition cascade between vinyl α-diketones and enones. The protocol allows access to a range of functionalized dihydrofuranones with good to high yields, and diverse further transformations on the products have been achieved. Furthermore, the mechanistic studies reveal that the 1,2-hydride shift occurs simultaneously during the dihydrofuranone formation.
Collapse
Affiliation(s)
- Ting Chen
- College of Chemistry, Fuzhou University, Fuzhou 350116, China
| | - Fan Gong
- College of Chemistry, Fuzhou University, Fuzhou 350116, China
| | - Sakkani Nagaraju
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
| | - Jinggong Liu
- Orthopedics Department, Guangdong Provincial Hospital of Traditional Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Shuang Yang
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
| | - Xingkuan Chen
- Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Department of Chemistry, Jinan University, Guangzhou 510632, China
| | - Xinqiang Fang
- College of Chemistry, Fuzhou University, Fuzhou 350116, China
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
| |
Collapse
|
2
|
Enyne diketones as substrate in asymmetric Nazarov cyclization for construction of chiral allene cyclopentenones. Nat Commun 2022; 13:3146. [PMID: 35672319 PMCID: PMC9174488 DOI: 10.1038/s41467-022-30846-y] [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: 01/12/2022] [Accepted: 05/17/2022] [Indexed: 11/08/2022] Open
Abstract
The Nazarov cyclization is one of the most powerful tools for the stereoselective synthesis of various cyclopentenone scaffolds. Therefore, developing the new classes substrate of Nazarov reaction is an important endeavor in synthetic chemistry. Herein, we report enyne diketones, enables diastereo- and enantioselective construction of chiral allene cyclopentenones in moderate to good yields with good enantioselectivities (up to 97% ee). Importantly, it is a typical example for asymmetric synthesis of cyclopentanones with allene moiety using Nazarov cyclisation. Mechanistic studies indicate that this metal-organo relay catalysis protocol involves a rhodium-catalyzed tandem oxonium ylide formation/[2,3]-sigmatropic rearrangement/reverse benzylic acid rearrangement, followed by organo-catalyzed asymmetric Nazarov cyclization/alkyne-to-allene isomerization to give the final chiral allene cyclopentenones.
Collapse
|
3
|
Tandem acid-promoted intramolecular azide-hydrazone electrocyclization/hydrolysis approach for the synthesis of N-Aminotetrazoles. Tetrahedron 2022. [DOI: 10.1016/j.tet.2021.132563] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
4
|
Recent Advances in Oxa-6π Electrocyclization Reactivity for the Synthesis of Privileged Natural Product Scaffolds. ORGANICS 2021. [DOI: 10.3390/org2040021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The stunning advances in understanding the reactivity and selectivity principles of asymmetric pericyclic reactions have had a profound impact on the synthetic planning of complex natural products. Indeed, electrocyclizations, cycloadditions, and sigmatropic rearrangements enable synthetic chemists to craft highly functionalized scaffolds that would not otherwise be possible with a similar atom-, step-, and redox-economy. In this review, selected examples from the last two decades of research (2003–2020) on tandem processes combining oxa-6π electrocyclic reactions are discussed in terms of reactivity challenges, inherent reversibility, and key structural bond formation in the assembly of natural products. A particular emphasis is given to the electrocyclic ring-closures in the tandem processes featuring Knoevenagel-type condensations, Diels–Alder cycloadditions, Stille couplings, and oxidative dearomatizations. The synthetic manifolds reviewed here illustrate how oxa-6π electrocyclizations are intimately linked to the construction of complex natural product scaffolds and have inspired a number of biomimetic syntheses in the laboratory.
Collapse
|
5
|
Abstract
The defining feature of the Nazarov cyclization is a 4π-conrotatory electrocyclization, resulting in the stereospecific formation of functionalized cyclopentanones. The reaction provides access to structural motifs that are found in many natural products and drug targets. Harnessing the full potential of the Nazarov cyclization broadens its utility by enabling the development of new methodologies and synthetic strategies. To achieve these goals through efficient cyclization design, it is helpful to think of the reaction as a two-stage process. The first stage involves a 4π-electrocyclization leading to the formation of an allylic cation, and the second stage corresponds to the fate of this cationic intermediate. With a complete understanding of the discrete events that characterize the overall process, one can optimize reactivity and control the selectivity of the different Stage 2 pathways.In this Account, we describe the development of methods that render the Nazarov cyclization catalytic and chemoselective, focusing specifically on advances made in our lab between 2002 and 2015. The initial discovery made in our lab involved reactions of electronically asymmetric ("polarized") substrates, which cyclize efficiently in the catalytic regime using mild Lewis acidic reagents. These cyclizations also exhibit selective eliminative behavior, increasing their synthetic utility. Research directed toward catalytic asymmetric Nazarov cyclization led to the serendipitous discovery of a 4π-cyclization coupled to a well-behaved Wagner-Meerwein rearrangement, representing an underexplored Stage 2 process. With careful choice of promoter and loading, it is possible to access either the rearrangement or the elimination pathway. Additional experimental and computational studies provided an effective model for anticipating the migratory behavior of substiutents in the rearrangements. Problem-solving efforts prompted investigation of alternative methods for generating pentadienyl cation intermediates, including oxidation of allenol ethers and addition of nucleophiles to dienyl diketones. These Nazarov cyclization variants afford cyclopentenone products with vicinal stereogenic centers and a different arrangement of substituents around the ring. A nucleophilic addition/cyclization/elimination sequence can be executed enantioselectively using catalytic amounts of a nonracemic chiral tertiary amine.In summary, the discovery and development of several new variations on the Nazarov electrocyclization are described, along with synthetic applications. This work illustrates how strongly substitution patterns can impact the efficiency of the 4π-electrocyclization (Stage 1), allowing for mild Lewis acid catalysis. Over the course of these studies, we have also identified new ways to access the critical pentadienyl cation intermediates and demonstrated strategies that exploit and control the different cationic pathways available post-electrocyclization (Stage 2 processes). These advances in Nazarov chemistry were subsequently employed in the synthesis of natural product targets such as (±)-merrilactone A, (±)-rocaglamide, and (±)-enokipodin B.
Collapse
Affiliation(s)
- Alison J. Frontier
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Jackson J. Hernandez
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| |
Collapse
|
6
|
Haslak ZP, Agopcan Cinar S, Sarigul Ozbek S, Monard G, Dogan I, Aviyente V. Elucidation of the atroposelectivity in the synthesis of axially chiral thiohydantoin derivatives. Org Biomol Chem 2020; 18:2233-2241. [PMID: 32022073 DOI: 10.1039/c9ob02556a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recently, Sarigul and Dogan have synthesized a number of enantiomerically enriched axially chiral atropoisomeric 2-thiohydantoins by the reaction of l-amino acid ester salts and o-aryl isothiocyanates in the presence of triethyl amine (TEA) in dichloromethane. The non-axially chiral derivative 5-methyl-3-phenyl-2-thiohydantoin gave a racemic product whereas the axially chiral 5-methyl-3-o-bromophenyl-2-thiohydantoin was less prone to racemize at C5 of the heterocyclic ring. In this study, we present a computational study (M06-2X/6-311+G(d,p) for C, H, O, N and S; M06-2X/6-311++G(3df,3pd) for Br) in order to propose plausible mechanisms for the racemization and cyclization steps for 2-thiohydantoin derivatives. The study includes rationalization based on steric as well as the electrostatic effects to elucidate the epimerization differences at C5.
Collapse
Affiliation(s)
- Zeynep Pinar Haslak
- Department of Chemistry, Bogaziçi University, Bebek, Istanbul, 34342, Turkey. and Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France and Faculty of Science and Letters, Piri Reis University, Tuzla, Istanbul, 34940, Turkey
| | - Sesil Agopcan Cinar
- Department of Chemistry, Bogaziçi University, Bebek, Istanbul, 34342, Turkey.
| | - Sevgi Sarigul Ozbek
- Faculty of Pharmacy, Acibadem Mehmet Ali Aydinlar University, Atasehir, Istanbul, 34752, Turkey
| | - Gérald Monard
- Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France
| | - Ilknur Dogan
- Department of Chemistry, Bogaziçi University, Bebek, Istanbul, 34342, Turkey.
| | - Viktorya Aviyente
- Department of Chemistry, Bogaziçi University, Bebek, Istanbul, 34342, Turkey.
| |
Collapse
|
7
|
Sugimoto K, Oshiro M, Hada R, Matsuya Y. 2,2'-Biphenol/B(OH) 3 Catalyst System for Nazarov Cyclization. Chem Pharm Bull (Tokyo) 2019; 67:1019-1022. [PMID: 31474725 DOI: 10.1248/cpb.c19-00399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A novel catalyst system-a combination of the readily available 2,2'-biphenol with the inexpensive, nontoxic, and eco-friendly B(OH)3-promoted the Nazarov cyclization of activated and inactivated divinyl ketones to afford the corresponding cyclopentenones up to 96% yield under, in a cis-selective manner. Compared with the conventional harsh conditions with hazardous reagents, user-friendly method was established with bench-stable and easy-to-handle reagents.
Collapse
Affiliation(s)
- Kenji Sugimoto
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Miyu Oshiro
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Ryuhei Hada
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Yuji Matsuya
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| |
Collapse
|
8
|
Tejedor D, Delgado-Hernández S, Diana-Rivero R, Díaz-Díaz A, García-Tellado F. A Domino Strategy for the Synthesis of 2H
-Pyrans from Propargyl Vinyl Ethers. European J Org Chem 2019. [DOI: 10.1002/ejoc.201801847] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- David Tejedor
- Instituto de Productos Naturales y Agrobiología; Consejo Superior de Investigaciones Científicas, Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife; Spain
| | - Samuel Delgado-Hernández
- Instituto de Productos Naturales y Agrobiología; Consejo Superior de Investigaciones Científicas, Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife; Spain
- Doctoral and Postgraduate School; Universidad de La Laguna; Spain
| | - Raquel Diana-Rivero
- Instituto de Productos Naturales y Agrobiología; Consejo Superior de Investigaciones Científicas, Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife; Spain
- Doctoral and Postgraduate School; Universidad de La Laguna; Spain
| | - Abián Díaz-Díaz
- Instituto de Productos Naturales y Agrobiología; Consejo Superior de Investigaciones Científicas, Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife; Spain
- Doctoral and Postgraduate School; Universidad de La Laguna; Spain
| | - Fernando García-Tellado
- Instituto de Productos Naturales y Agrobiología; Consejo Superior de Investigaciones Científicas, Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife; Spain
| |
Collapse
|
9
|
Borowski D, Oechsner RM, Jürgens E, Ziegler T. Carbohydrate-Derived 3,2-Enolones in the Base-Catalyzed Rearrangement to Highly Functionalized C
4-Quaternary 4-Hydroxy-2-cyclopentenones. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Daniel Borowski
- Institute of Organic Chemistry; University of Tuebingen; Auf der Morgenstelle 18 72076 Tuebingen Germany
| | - Regina M. Oechsner
- Institute of Organic Chemistry; University of Tuebingen; Auf der Morgenstelle 18 72076 Tuebingen Germany
| | - Eva Jürgens
- Institute of Inorganic Chemistry; University of Tuebingen; Auf der Morgenstelle 18 72076 Tuebingen Germany
| | - Thomas Ziegler
- Institute of Organic Chemistry; University of Tuebingen; Auf der Morgenstelle 18 72076 Tuebingen Germany
| |
Collapse
|
10
|
Carmichael RA, Chalifoux WA. One-pot synthesis of [6-5-6] tricyclic products via a double Diels-Alder/Nazarov tandem reaction of unsymmetrically substituted cross-conjugated diynones. Tetrahedron 2017. [DOI: 10.1016/j.tet.2016.11.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
11
|
Chang L, Plevová K, Thorimbert S, Dechoux L. Preparation of Substituted 2H-Pyrans via a Cascade Reaction from Methyl Coumalate and Activated Methylene Nucleophiles. J Org Chem 2017; 82:5499-5505. [PMID: 28471191 DOI: 10.1021/acs.joc.7b00761] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of methyl coumalate with a wide range of methylene active compounds, such as keto-esters or keto-sulfones and cyclic or acyclic diketones, afforded more than 30 2,3,5,6-tetrasubstituted 2H-pyrans. The reaction proceeds via a cascade reaction involving a Michael addition-6π-electrocyclic ring opening-proton transfer and 6π electrocyclization, in which a variety of functional groups were tolerated.
Collapse
Affiliation(s)
- Liang Chang
- Sorbonne Universités , UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, F-75005 Paris, France
| | - Kristína Plevová
- Sorbonne Universités , UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, F-75005 Paris, France
| | - Serge Thorimbert
- Sorbonne Universités , UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, F-75005 Paris, France
| | - Luc Dechoux
- Sorbonne Universités , UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, F-75005 Paris, France
| |
Collapse
|
12
|
Carmichael RA, Sophanpanichkul P, Chalifoux WA. β-Silyl-Assisted Tandem Diels–Alder/Nazarov Reaction of 1-Aryl-3-(trimethylsilyl) Ynones. Org Lett 2017; 19:2592-2595. [DOI: 10.1021/acs.orglett.7b00911] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Rachael A. Carmichael
- Department of Chemistry, University of Nevada—Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Punyanuch Sophanpanichkul
- Department of Chemistry, University of Nevada—Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Wesley A. Chalifoux
- Department of Chemistry, University of Nevada—Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| |
Collapse
|
13
|
Hall AJ, Roche SP, West LM. Synthesis of Briarane Diterpenoids: Biomimetic Transannular Oxa-6π electrocyclization Induced by a UVA/UVC Photoswitch. Org Lett 2017; 19:576-579. [PMID: 28080074 DOI: 10.1021/acs.orglett.6b03689] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A biomimetic synthesis of briareolate ester B (3) from briareolate ester L (1) via the intermediate briareolate ester G (2) has been achieved through a unique transannular oxa-6π electrocyclization induced by UVA light. UVC irradiation of 3 triggered a rapid retro-6π electrocyclization to establish an unprecedented photochromic switch. In the ground state, reaction of 1 led to the formation of a polycyclic γ-spiroketal γ-lactone 5, architecturally related to the ether-bridged cembranoids of the cladiellin class.
Collapse
Affiliation(s)
- Andrew J Hall
- Department of Chemistry and Biochemistry, Florida Atlantic University , Boca Raton, Florida 33431, United States
| | - Stéphane P Roche
- Department of Chemistry and Biochemistry, Florida Atlantic University , Boca Raton, Florida 33431, United States
| | - Lyndon M West
- Department of Chemistry and Biochemistry, Florida Atlantic University , Boca Raton, Florida 33431, United States
| |
Collapse
|
14
|
Abstract
The acid-promoted cycloisomerization of conjugated dienals and linearly-conjugated dienones for the synthesis of five-membered ring systems is reviewed.
Collapse
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
| |
Collapse
|
15
|
Huang YW, Frontier AJ. Nazarov Cyclization/Internal Redox Cyclization Sequence for the Synthesis of N-Heterocyclic Bridged Ring Systems. Org Lett 2016; 18:4896-4899. [DOI: 10.1021/acs.orglett.6b02369] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yu-Wen Huang
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, United States
| | - Alison J. Frontier
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, United States
| |
Collapse
|
16
|
Głodek M, Makal A, Kłys A, Zakrzewski J, Plażuk D. Direct Synthesis of Perylene-Fused Cyclic Ketones from Perylene and 2-Alkenoic Acids. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Marta Głodek
- Department of Organic Chemistry; University of Łódź; Faculty of Chemistry; Tamka 12 91-403 Łódź Poland
| | - Anna Makal
- Department of Chemistry; Warsaw University; Pasteura 1 02-093 Warszawa Poland
| | - Arkadiusz Kłys
- Laboratory of Molecular Spectroscopy; University of Łódź; Faculty of Chemistry; Tamka 12 91-403 Łódź Poland
| | - Janusz Zakrzewski
- Department of Organic Chemistry; University of Łódź; Faculty of Chemistry; Tamka 12 91-403 Łódź Poland
| | - Damian Plażuk
- Department of Organic Chemistry; University of Łódź; Faculty of Chemistry; Tamka 12 91-403 Łódź Poland
| |
Collapse
|
17
|
Itoh T, Nokami T, Kawatsura M. Recent Progress on Nazarov Cyclizations: The Use of Iron Salts as Catalysts in Ionic Liquid Solvent Systems. CHEM REC 2016; 16:1676-89. [PMID: 27219324 DOI: 10.1002/tcr.201600021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Indexed: 12/21/2022]
Abstract
Nazarov cyclization is an important and versatile method for the synthesis of five-membered carbocycles, and extensive studies have been conducted to optimize the reaction. Among recent studies, several trends are recognized. One is the combination of different reactions with Nazarov cyclization in a one-pot reaction system which enables the preparation of unique cyclization products. The second is the use of a transition-metal catalyst, though Lewis or Brønsted acids have generally been used for the reaction. The third is the realization of the asymmetric Nazarov cyclization. The fourth is the base-catalyzed Nazarov cyclization. Furthermore, several useful protocols for realizing Nazarov cyclization have also been developed. The recent progress on Nazarov cyclizations is summarized in Section 2. Section 3 is our chronicle in this field. We focused on the use of iron as the catalyst in Nazarov cyclizations and ionic liquids as solvents: Nazarov cyclization of thiophene derivatives using FeCl3 as the catalyst was accomplished and we succeeded in demonstrating the first example of an iron-catalyzed asymmetric Nazarov reaction. We next established Nazarov cyclization of pyrrole or indole derivatives using Fe(ClO4 )3 ·Al2 O3 as the catalyst with high trans selectivities in excellent yields. Since the cyclized product was reacted with a vinyl ketone in the presence of the same iron salt, the system allowed realization of the sequential type of Nazarov/Michael reaction of pyrrole derivatives. Furthermore, we demonstrated the recyclable use of the iron catalyst and obtained the desired Nazarov/Michael reaction products in good yields for five repetitions of the reactions without any addition of the catalyst using an ionic liquid, [bmim][NTf2 ], as the solvent. We expect that the iron-catalyzed Nazarov cyclization, in particular, in an ionic liquid solvent might become a useful method to synthesize functional molecules that include cycloalkene moieties.
Collapse
Affiliation(s)
- Toshiyuki Itoh
- Department of Chemistry and Biotechnology, Graduate School of Engineering and Center for Research on Green Sustainable Chemistry, Tottori University, 4-101 Koyama-minami, Tottori, 680-852, Japan
| | - Toshiki Nokami
- Department of Chemistry and Biotechnology, Graduate School of Engineering and Center for Research on Green Sustainable Chemistry, Tottori University, 4-101 Koyama-minami, Tottori, 680-852, Japan
| | - Motoi Kawatsura
- Department of Chemistry, College of Humanities and Science, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo, 156-8550, Japan
| |
Collapse
|
18
|
Manisha M, Dhiman S, Mathew J, Ramasastry SSV. One-pot relay catalysis: divergent synthesis of furo[3,4-b]indoles and cyclopenta[b]indoles from 3-(2-aminophenyl)-1,4-enynols. Org Biomol Chem 2016; 14:5563-8. [DOI: 10.1039/c6ob00319b] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Described herein a divergent strategy for the synthesis of furo[3,4-b]indoles via a sequential Ag(i)/Bi(iii)/Pd(ii) catalysis and cyclopenta[b]indoles via a one-pot Ag(i)/Brønsted acid relay catalysis, starting from the easily accessible 3-(2 aminophenyl)-4-pentenyn-3-ols.
Collapse
Affiliation(s)
- Manisha Manisha
- Organic Synthesis and Catalysis Lab
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manuali PO
- India
| | - Seema Dhiman
- Organic Synthesis and Catalysis Lab
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manuali PO
- India
| | - Jopaul Mathew
- Organic Synthesis and Catalysis Lab
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manuali PO
- India
| | - S. S. V. Ramasastry
- Organic Synthesis and Catalysis Lab
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manuali PO
- India
| |
Collapse
|
19
|
Huang YW, Frontier AJ. Enantioselective Nazarov Cyclization Catalyzed by a Cinchona Alkaloid Derivative. Tetrahedron Lett 2015; 56:3523-3526. [PMID: 26085696 PMCID: PMC4465120 DOI: 10.1016/j.tetlet.2014.12.136] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nucleophilic catalysts for a 1,6 addition/Nazarov cyclization/elimination sequence were evaluated for their ability to induce enantioselectivity in the electrocyclization step. Of the tertiary amines examined, it was found that a cinchona alkaloid derivative was able to generate substituted 5-hydroxy γ-methylene cyclopentenones with excellent enantioselectivity. The study results suggest that successful cyclization depends upon the ability of the dienyl diketone substrate to readily adopt an s-cis conformation.
Collapse
Affiliation(s)
- Yu-Wen Huang
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Alison J. Frontier
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| |
Collapse
|
20
|
Yadav AK, Yadav LDS. Visible-light-driven electrocyclization of activated allylic amines via azomethine ylide formation. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2014.12.063] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
21
|
|