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Search for "Nazarov reaction" in Full Text gives 8 result(s) in Beilstein Journal of Organic Chemistry.
Recent advancements in the synthesis of Veratrum alkaloids
- Morwenna Mögel,
- David Berger and
- Philipp Heretsch
Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206
- resulted in a hydroxy group, which was oxidized to furnish Nazarov precursor 54 in 52% yield. Key step of this sequence was the photoinduced excited-state Nazarov reaction, which involved irradiation of 54 in dichloroethane at 366 nm for 30 min at room temperature. Remarkably, this method had been
Graphical Abstract
Scheme 1: Representatives of steroid alkaloid classes. Marked in blue is the steroidal cholestane framework, ...
Scheme 2: Subclasses of Veratrum alkaloids: jervanine, veratramine and cevanine-type [8].
Scheme 3: Flow chart presentation of the synthesis of (−)-englerin A developed by the Christmann group [10].
Scheme 4: Structures and year of synthesis of the three types of Veratrum alkaloids reported in the literatur...
Scheme 5: Key step in the synthesis of cyclopamine (6) by the Giannis group [21].
Scheme 6: Overview of the semisynthesis of cyclopamine (6) reported by the Giannis group in 2009 [21].
Scheme 7: Key steps in the synthesis of cyclopamine (6) by the Baran group [23].
Scheme 8: Overview of the total synthesis of cyclopamine (6) by the Baran group in 2023 [23].
Scheme 9: Key steps in the synthesis of cyclopamine (6) by the Zhu/Gao group [25].
Scheme 10: Overview of the total synthesis of cyclopamine (6) by the group of Zhao/Gao in 2023 [25].
Scheme 11: Key steps in the synthesis of cyclopamine (6) by the Liu/Qin group [26].
Scheme 12: Overview of the semisynthesis of cyclopamine (6) by the Liu/Qin group in 2024 [26].
Scheme 13: Key steps in the synthesis of jervine (12) by the Masamune group [14].
Scheme 14: Overview of the total synthesis of jervine (12) by the Masamune group in 1968 [14].
Scheme 15: Color-coded schemes of the presented cyclopamine (6) syntheses by Giannis, Baran, Zhu/Gao, and Liu/...
Scheme 16: Key steps in the total synthesis of veratramine (13) by the Johnson group [15].
Scheme 17: Overview of the total synthesis of veratramine (13) by the Johnson group in 1967 [15].
Scheme 18: Key steps in the synthesis of veratramine (13) by the Zhu/Gao group [25].
Scheme 19: Shortened overview of the total synthesis of veratramine (13) by the Zhu/Gao group in 2023 [25].
Scheme 20: Key steps in the synthesis of veratramine by the Liu/Qin group [26].
Scheme 21: Overview of the semisynthesis of veratramine (13) by the Liu/Qin group in 2024 [26].
Scheme 22: Key steps in the synthesis of veratramine (13) by the Trauner group [27].
Scheme 23: Overview of the total synthesis of veratramine (13) by the Trauner group in 2025 [27].
Scheme 24: Key steps in the synthesis of verarine (14) by the Kutney group [16-19].
Scheme 25: Overview of the total synthesis of verarine (14) by the Kutney group reported 1962–1968 [16-19].
Scheme 26: Color-coded schemes of the presented veratramine-type alkaloid synthesis of Zhu/Gao, Liu/Qin and Tr...
Scheme 27: Structures of veracevine (86), veratridine (87), and cevadine (88).
Scheme 28: Key step in the semisynthesis of verticine (15) by the Kutney group (1977) [20,46].
Scheme 29: Overview of the semisynthesis of verticine (15) by the Kutney group (1977) [20,46].
Scheme 30: Key step of the total synthesis of (±)-4-methylenegermine (17) by the Stork group (2017) [22].
Scheme 31: Overview of the total synthesis of (±)-4-methylenegermine (17) by the Stork group (2017) [22].
Scheme 32: Key step of the total synthesis of heilonine (16) by Cassaidy and Rawal (2021) [24].
Scheme 33: Overview of the total synthesis of heilonine (16) by Cassaidy and Rawal (2021) [24]. FGI: functional gr...
Scheme 34: Key steps of the synthesis of heilonine (16) by Dai and co-workers (2024) [28].
Scheme 35: Overview of the total synthesis of heilonine (16) by Dai and co-workers (2024) [28].
Scheme 36: Key steps of the total synthesis of zygadenine (18) reported by Luo and co-workers [29].
Scheme 37: Overview of the total synthesis of zygadenine (18) by Luo and co-workers (2023) [29].
Scheme 38: Key step of the divergent total syntheses of highly oxidized cevanine-type alkaloids by Luo and co-...
Scheme 39: Divergent syntheses of highly oxidized cevanine-type alkaloids by Luo and co-workers (2024) [30].
Scheme 40: Color-coded overview of the presented cevanine-type alkaloid syntheses [10,20,22,24,28-30,46]. LLS: longest linear sequen...
Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction
- Manoel T. Rodrigues Jr.,
- Aline S. B. de Oliveira,
- Ralph C. Gomes,
- Amanda Soares Hirata,
- Lucas A. Zeoly,
- Hugo Santos,
- João Arantes,
- Catarina Sofia Mateus Reis-Silva,
- João Agostinho Machado-Neto,
- Leticia Veras Costa-Lotufo and
- Fernando Coelho
Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99
- ; indanones; Nazarov reaction; Introduction Natural products are the source of inspiration for several research groups that develop new synthetic methodologies. The chemistry of five-membered rings plays an important role in organic chemistry, both because of the wide occurrence in nature [1][2][3][4][5][6
- [15], and the Nazarov reaction [16][17][18][19][20]. The Nazarov cyclization is one of the most versatile and simple methods for preparing indanones from aryl vinyl ketone derivatives [16][17][18][19][20]. The Nazarov reaction is classically formulated as a 4π conrotatory electrocyclization of a
- pentadienyl cation [1][2][3][4][5][6][7][8][9][10][11][12]. Until the past decade, the conditions used for the Nazarov reaction generally involved the use of a stoichiometric amount of a strong Lewis acid (e.g., BF3, TiCl4, SnCl4, AlCl3) in relation to the divinyl ketone derivative [21][22][23]. However
Graphical Abstract
Figure 1: Examples of different compounds containing the indanone moiety.
Figure 2: Synthesis of unsaturated β-ketoesters (Knoevenagel derivatives). aIsolated yield after purification...
Figure 3: Synthesis of 3-aryl-2-ethoxycarbonyl-1-indanones mediated by bismuth triflate. aIsolated yield afte...
Scheme 1: Previous methods describing decarboxylation reactions of indanones and xanthenones.
Figure 4: Controlled decarboxylation directed by bismuth triflate at 100 °C. Synthesis of 3-aryl-1-indanones. ...
Figure 5: Impact of indanone derivatives on cell viability of tumor cells. Cell viability was determined by M...
Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles
- Bilge Banu Yagci,
- Selin Ezgi Donmez,
- Onur Şahin and
- Yunus Emre Türkmen
Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6
- Research Center, Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Turkey 10.3762/bjoc.19.6 Abstract We have developed a catalytic aza-Nazarov reaction of N-acyliminium salts generated in situ from the reaction of a variety of cyclic and acyclic imines with α,β
- cyclization of 3,4-dihydroisoquinolines with α,β-unsaturated acyl chlorides gives tricyclic lactam products 7 in up to 79% yield with full diastereocontrol (dr = >99:1). The use of acyclic imines in a similar catalytic aza-Nazarov reaction with 20 mol % of AgOTf results in the formation of α-methylene-γ
- on the success of the catalytic aza-Nazarov reaction. Keywords: α-methylene-γ-lactam; aza-Nazarov reaction; β-silicon effect; heterocycles; intramolecular cyclization; Introduction The rapid construction of aliphatic heterocycles from acyclic building blocks via cyclization or cycloaddition
Graphical Abstract
Scheme 1: Examples of aza-Nazarov reactions.
Scheme 2: Aza-Nazarov cyclization on gram scale.
Scheme 3: Scope of the aza-Nazarov cyclization with acyclic imines. aThe syntheses of aza-Nazarov products 19b...
Figure 1: X-ray crystal structure of compound 19l.
Scheme 4: Proposed mechanism for the formation of diastereomers 19 and 22.
Scheme 5: Preparation of acyl chloride 23.
Scheme 6: Aza-Nazarov reaction tested using β-TMS-substituted acyl chloride 23.
Scheme 7: Hydrolysis of N-acyliminium intermediates.
Scheme 8: (a) Two possible pathways for the formation of 7 and (b) investigation of the reaction between imin...
Scheme 9: (a) Preparation of acyl chlorides 6ba and 6bb in diastereomerically pure forms, (b) aza-Nazarov cyc...
Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: a computational study on the crucial role of the nitrogen atom
- Giovanna Zanella,
- Martina Petrović,
- Dina Scarpi,
- Ernesto G. Occhiato and
- Enrique Gómez-Bengoa
Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255
- Studi di Firenze, Via della Lastruccia 13, 50019 Sesto Fiorentino, Florence, Italy 10.3762/bjoc.16.255 Abstract The tandem gold(I)-catalyzed rearrangement/Nazarov reaction of enynyl acetates in which the double bond is embedded in a piperidine ring was computationally and experimentally studied. The
- position 3 was computed to have a deleterious effect on the electronic properties of the molecules, increasing the activation barriers of the Nazarov reaction. The sluggish reactivity of 3-substituted piperidines predicted by the calculations was further confirmed by the results obtained with some designed
- substrates. Keywords: DFT calculations; gold catalysis; Nazarov reaction; N-heterocycles; Introduction In the development of new and effective catalysts, step economy is surely one of the major goals. A reduction of the number of steps in the synthesis of complex compounds can be attained by cascade
Graphical Abstract
Figure 1: Tandem acetate rearrangement/Nazarov cyclization of different substrates.
Figure 2: DFT-computed energy profile of the tandem Au(I)-catalyzed [3,3]-rearrangement/Nazarov reaction of 3...
Figure 3: DFT-computed energy profile of the tandem Au(I)-catalyzed [3,3]-rearrangement/Nazarov reaction of 2...
Figure 4: Computed comparison of the NBO charges of 2- and 3-substituted substrates.
Figure 5: Single-step transformation of IV to IX.
Figure 6: Triflate-promoted hydrogen abstraction and protodeauration with HOTf.
Figure 7: Triflate-mediated abstraction of the hydrogen atom Ha and protodeauration.
Scheme 1: Synthesis of the enynyl acetate starting material 14.
Scheme 2: Synthesis and cyclization of enynyl acetate 20.
Synthesis of 1-indanones with a broad range of biological activity
- Marika Turek,
- Dorota Szczęsna,
- Marek Koprowski and
- Piotr Bałczewski
Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48
- neurodegenerative diseases and as effective insecticides, fungicides and herbicides. Keywords: biological activity; Diels–Alder reaction; Friedel–Crafts reaction; 1-indanones; Nazarov reaction; Introduction In the last few years, 1-indanone derivatives and their structural analogues have been widely used in
- their synthesis (Figure 2). The commonly used reaction in this area is the Nazarov reaction which employs α,β-unsaturated ketones as substrates and is carried out in the presence of Brønsted or Lewis acids. Despite extensive studies on 1-indanones and their biological activity, this group of compounds
- turned out to be particularly interesting because of its application in the synthesis of anticancer compounds [62]. 1.1.6 From 1,3-dienones: The major role in the synthesis of 1-indanones plays the Nazarov reaction of 1,3-dienones in which one of two double bonds is derived from the aromatic system
Graphical Abstract
Figure 1: Biologically active 1-indanones and their structural analogues.
Figure 2: Number of papers about (a) 1-indanones, (b) synthesis of 1-indanones.
Scheme 1: Synthesis of 1-indanone (2) from hydrocinnamic acid (1).
Scheme 2: Synthesis of 1-indanone (2) from 3-(2-bromophenyl)propionic acid (3).
Scheme 3: Synthesis of 1-indanones 5 from 3-arylpropionic acids 4.
Scheme 4: Synthesis of kinamycin (9a) and methylkinamycin C (9b).
Scheme 5: Synthesis of trifluoromethyl-substituted arylpropionic acids 12, 1-indanones 13 and dihydrocoumarin...
Scheme 6: Synthesis of 1-indanones 16 from benzoic acids 15.
Scheme 7: Synthesis of 1-indanones 18 from arylpropionic and 3-arylacrylic acids 17.
Scheme 8: The NbCl5-induced one-step synthesis of 1-indanones 22.
Scheme 9: Synthesis of biologically active 1-indanone derivatives 26.
Scheme 10: Synthesis of enantiomerically pure indatraline ((−)-29).
Scheme 11: Synthesis of 1-indanone (2) from the acyl chloride 30.
Scheme 12: Synthesis of the mechanism-based inhibitors 33 of coelenterazine.
Scheme 13: Synthesis of the indane 2-imidazole derivative 37.
Scheme 14: Synthesis of fluorinated PAHs 41.
Scheme 15: Synthesis of 1-indanones 43 via transition metal complexes-catalyzed carbonylative cyclization of m...
Scheme 16: Synthesis of 6-methyl-1-indanone (46).
Scheme 17: Synthesis of 1-indanone (2) from ester 48.
Scheme 18: Synthesis of benzopyronaphthoquinone 51 from the spiro-1-indanone 50.
Scheme 19: Synthesis of the selective endothelin A receptor antagonist 55.
Scheme 20: Synthesis of 1-indanones 60 from methyl vinyl ketone (57).
Scheme 21: Synthesis of 1-indanones 64 from diethyl phthalate 61.
Scheme 22: Synthesis of 1-indanone derivatives 66 from various Meldrum’s acids 65.
Scheme 23: Synthesis of halo 1-indanones 69.
Scheme 24: Synthesis of substituted 1-indanones 71.
Scheme 25: Synthesis of spiro- and fused 1-indanones 73 and 74.
Scheme 26: Synthesis of spiro-1,3-indanodiones 77.
Scheme 27: Mechanistic pathway for the NHC-catalyzed Stetter–Aldol–Michael reaction.
Scheme 28: Synthesis of 2-benzylidene-1-indanone derivatives 88a–d.
Scheme 29: Synthesis of 1-indanone derivatives 90a–i.
Scheme 30: Synthesis of 1-indanones 96 from o-bromobenzaldehydes 93 and alkynes 94.
Scheme 31: Synthesis of 3-hydroxy-1-indanones 99.
Scheme 32: Photochemical preparation of 1-indanones 103 from ketones 100.
Scheme 33: Synthesis of chiral 3-aryl-1-indanones 107.
Scheme 34: Photochemical isomerization of 2-methylbenzil 108.
Scheme 35: Synthesis of 2-hydroxy-1-indanones 111a–c.
Scheme 36: Synthesis of 1-indanone derivatives 113 and 114 from η6-1,2-dioxobenzocyclobutene complex 112.
Scheme 37: Synthesis of nakiterpiosin (117).
Scheme 38: Synthesis of 2-alkyl-1-indanones 120.
Scheme 39: Synthesis of fluorine-containing 1-indanone derivatives 123.
Scheme 40: Synthesis of 2-benzylidene and 2-benzyl-1-indanones 126, 127 from the chalcone 124.
Scheme 41: Synthesis of 2-bromo-6-methoxy-3-phenyl-1-indanone (130).
Scheme 42: Synthesis of combretastatin A-4-like indanones 132a–s.
Figure 3: Chemical structures of investigated dienones 133 and synthesized cyclic products 134–137.
Figure 4: Chemical structures of 1-indanones and their heteroatom analogues 138–142.
Scheme 43: Synthesis of 2-phosphorylated and 2-non-phosphorylated 1-indanones 147 and 148 from β-ketophosphona...
Scheme 44: Photochemical synthesis of 1-indanone derivatives 150, 153a, 153b.
Scheme 45: Synthesis of polysubstituted-1-indanones 155, 157.
Scheme 46: Synthesis of 1-indanones 159a–g from α-arylpropargyl alcohols 158 using RhCl(PPh3)3 as a catalyst.
Scheme 47: Synthesis of optically active 1-indanones 162 via the asymmetric Rh-catalyzed isomerization of race...
Scheme 48: Mechanism of the Rh-catalyzed isomerization of α-arylpropargyl alcohols 161 to 1-indanones 162.
Figure 5: Chemical structure of abicoviromycin (168) and its new benzo derivative 169.
Scheme 49: Synthesis of racemic benzoabicoviromycin 172.
Scheme 50: Synthesis of [14C]indene 176.
Scheme 51: Synthesis of indanone derivatives 178–180.
Scheme 52: Synthesis of racemic pterosin A 186.
Scheme 53: Synthesis of trans-2,3-disubstituted 1-indanones 189.
Scheme 54: Synthesis of 3-aryl-1-indanone derivatives 192.
Scheme 55: Synthesis of 1-indanone derivatives 194 from 3-(2-iodoaryl)propanonitriles 193.
Scheme 56: Synthesis of 1-indanones 200–204 by cyclization of aromatic nitriles.
Scheme 57: Synthesis of 1,1’-spirobi[indan-3,3’-dione] derivative 208.
Scheme 58: Total synthesis of atipamezole analogues 211.
Scheme 59: Synthesis of 3-[4-(1-piperidinoethoxy)phenyl]spiro[indene-1,1’-indan]-5,5’-diol hydrochloride 216.
Scheme 60: Synthesis of 3-arylindan-1-ones 219.
Scheme 61: Synthesis of 2-hydroxy-1-indanones 222.
Scheme 62: Synthesis of the 1-indanone 224 from the THP/MOM protected chalcone epoxide 223.
Scheme 63: Synthesis of 1-indanones 227 from γ,δ-epoxy ketones 226.
Scheme 64: Synthesis of 2-hydroxy-2-methylindanone (230).
Scheme 65: Synthesis of 1-indanone derivatives 234 from cyclopropanol derivatives 233.
Scheme 66: Synthesis of substituted 1-indanone derivatives 237.
Scheme 67: Synthesis of 7-methyl substituted 1-indanone 241 from 1,3-pentadiene (238) and 2-cyclopentenone (239...
Scheme 68: Synthesis of disubstituted 1-indanone 246 from the siloxydiene 244 and 2-cyclopentenone 239.
Scheme 69: Synthesis of 5-hydroxy-1-indanone (250) via the Diels–Alder reaction of 1,3-diene 248 with sulfoxid...
Scheme 70: Synthesis of halogenated 1-indanones 253a and 253b.
Scheme 71: Synthesis of 1-indanones 257 and 258 from 2-bromocyclopentenones 254.
Scheme 72: Synthesis of 1-indanone 261 from 2-bromo-4-acetoxy-2-cyclopenten-1-one (260) and 1,2-dihydro-4-viny...
Scheme 73: Synthesis of 1-indanone 265 from 1,2-dihydro-7-methoxy-4-vinylnaphthalene (262) and bromo-substitut...
Scheme 74: Synthesis of 1-indanone 268 from dihydro-3-vinylphenanthrene 266 and 4-acetoxy-2-cyclopenten-1-one (...
Scheme 75: Synthesis of 1-indanone 271 from phenylselenyl-substituted cyclopentenone 268.
Scheme 76: Synthesis of 1-indanone 272 from the trienone 270.
Scheme 77: Synthesis of the 1-indanone 276 from the aldehyde 273.
Scheme 78: Synthesis of 1-indanones 278 and 279.
Scheme 79: Synthesis of 1-indanone 285 from octa-1,7-diyne (282) and cyclopentenone 239.
Scheme 80: Synthesis of benz[f]indan-1-one (287) from cyclopentenone 239 and o-bis(dibromomethyl)benzene (286)....
Scheme 81: Synthesis of 3-methyl-substituted benz[f]indan-1-one 291 from o-bis(dibromomethyl)benzene (286) and...
Scheme 82: Synthesis of benz[f]indan-1-one (295) from the anthracene epidioxide 292.
Scheme 83: Synthesis of 1-indanone 299 from homophthalic anhydride 298 and cyclopentynone 297.
Scheme 84: Synthesis of cyano-substituted 1-indanone derivative 301 from 2-cyanomethylbenzaldehyde (300) and c...
Scheme 85: Synthesis of 1-indanone derivatives 303–305 from ketene dithioacetals 302.
Scheme 86: Synthesis of 1-indanones 309–316.
Scheme 87: Mechanism of the hexadehydro-Diels–Alder (HDDA) reaction.
Scheme 88: Synthesis of 1-indenone 318 and 1-indanones 320 and 321 from tetraynes 317 and 319.
Scheme 89: Synthesis of 1-indanone 320 from the triyn 319.
Scheme 90: Synthesis 1-indanone 328 from 2-methylfuran 324.
Scheme 91: Synthesis of 1-indanones 330 and 331 from furans 329.
Scheme 92: Synthesis of 1-indanone 333 from the cycloadduct 332.
Scheme 93: Synthesis of (S)-3-arylindan-1-ones 335.
Scheme 94: Synthesis of (R)-2-acetoxy-1-indanone 338.
Figure 6: Chemical structures of obtained cyclopenta[α]phenanthrenes 339.
Scheme 95: Synthesis of the benzoindanone 343 from arylacetaldehyde 340 with 1-trimethylsilyloxycyclopentene (...
Some aspects of radical chemistry in the assembly of complex molecular architectures
- Béatrice Quiclet-Sire and
- Samir Z. Zard
Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61
- process leading to trans-decalin 104. This compound readily undergoes HWE condensation with an external aldehyde, such as benzaldehyde. It is worth noting that β-elimination of water from the resulting product 105 would lead to dienone 106, an interesting substrate for the Nazarov reaction which, in this
Graphical Abstract
Scheme 1: Key radical step in the total synthesis of (–)-dendrobine.
Scheme 2: Radical cascade in the total synthesis of (±)-13-deoxyserratine (ACCN = 1,1'-azobis(cyclohexanecarb...
Scheme 3: Formation of the complete skeleton of (±)-fortucine.
Scheme 4: Model radical sequence for the synthesis of quadrone.
Scheme 5: Radical cascade using the Barton decarboxylation.
Scheme 6: Simplified mechanism for the xanthate addition to alkenes.
Scheme 7: Synthesis of β-lactam derivatives.
Scheme 8: Sequential additions to three different alkenes (PhthN = phthalimido).
Scheme 9: Key cascade in the total synthesis of (±)-matrine (43).
Scheme 10: Synthesis of complex tetralones.
Scheme 11: Synthesis of functionalised azaindoline and indole derivatives.
Scheme 12: Synthesis of thiochromanones.
Scheme 13: Synthesis of complex benzothiepinones. Conditions: 1) CF3COOH; 2) RCHO / AcOH (PMB = p-methoxybenzy...
Scheme 14: Formation and capture of a cyclic nitrone.
Scheme 15: Synthesis of bicyclic cyclobutane motifs.
Scheme 16: Construction of the CD rings of steroids.
Scheme 17: Rapid assembly of polyquinanes.
Scheme 18: Formation of a polycyclic structure via an allene intermediate.
Scheme 19: A polycyclic structure via the alkylative Birch reduction.
Scheme 20: Synthesis of polycyclic pyrimidines and indoline structures.
Scheme 21: Construction of a trans-decalin derivative.
Scheme 22: Multiple uses of a chloroacetonyl xanthate.
Scheme 23: A convergent route to spiroketals.
Scheme 24: A modular approach to 3-arylpiperidines.
Scheme 25: A convergent route to cyclopentanols and to functional allenes.
Scheme 26: Allylation and vinylation of a xanthate and an iodide.
Scheme 27: Vinyl epoxides as allylating agents.
Scheme 28: Radical allylations using allylic alcohol derivatives.
Scheme 29: Synthesis of variously substituted lactams.
Scheme 30: Nickel-mediated synthesis of unsaturated lactams.
Scheme 31: Total synthesis of (±)-3-demethoxy-erythratidinone.
Scheme 32: Generation and capture of an iminyl radical from an oxime ester.
Solvent- and ligand-induced switch of selectivity in gold(I)-catalyzed tandem reactions of 3-propargylindoles
- Estela Álvarez,
- Delia Miguel,
- Patricia García-García,
- Manuel A. Fernández-Rodríguez,
- Félix Rodríguez and
- Roberto Sanz
Beilstein J. Org. Chem. 2011, 7, 786–793, doi:10.3762/bjoc.7.89
- -indole migration in 3-propargylindoles. Results and Discussion It is an intriguing possibility that the aura-Nazarov reaction may also take place with substrates bearing aromatic substituents at both the propargylic and terminal positions, and thus allow access to new functionalized indole derivatives
Graphical Abstract
Scheme 1: Formation of 3-(inden-2-yl)indoles 3 and 4 from 3-propargylindoles. Energy barriers (kcal/mol) for ...
Scheme 2: Tandem 1,2-indole migration/aura-Nazarov cyclization from 3-propargylindoles bearing an aromatic su...
Figure 1: ORTEP diagram for 4a. Ellipsoids are shown at 30% level (hydrogen atoms are omitted for clarity).
Scheme 3: Comparison of the reactivity of C-2 substituted indoles 1j and 1k. Conditions: a) (Ph3P)AuCl/AgSbF6...
Scheme 4: Reactions of 3-propargylindoles 1l and 1m with bulky alkyl substituents at the propargylic position...
Construction of cyclic enones via gold-catalyzed oxygen transfer reactions
- Leping Liu,
- Bo Xu and
- Gerald B. Hammond
Beilstein J. Org. Chem. 2011, 7, 606–614, doi:10.3762/bjoc.7.71
- the same authors (Scheme 5) [44]. Using enynones 7 as the substrate, the gold-catalyzed tandem alkyne–carbonyl metathesis/Nazarov reaction generated a number of intriguing fused bicyclic, tricyclic and tetracyclic derivatives of 8 in moderate to good yields and excellent diastereoselectivity. In this
Graphical Abstract
Scheme 1: Lewis acid or Brønsted acid-catalyzed alkyne–carbonyl metathesis and a proposed [2 + 2] intermediat...
Scheme 2: Gold-catalyzed cyclization of internal alkynyl ketones.
Scheme 3: Proposed [2 + 2] mechanism for the cyclization of alkynyl ketones.
Scheme 4: Gold-catalyzed cyclization of terminal alkynyl ketones.
Scheme 5: Gold-catalyzed tandem oxygen transfer/Nazarov cyclizations.
Scheme 6: TfOH-mediated cyclization of alkynyl ketones.
Scheme 7: Gold-catalyzed cyclizations of 2-alkynyl-1,5-diketones.
Scheme 8: Designed isotopic labeling experiment for mechanistic studies.
Scheme 9: 18O isotopic experiments.
Scheme 10: B2PLYP/6-311+G(d,p)//B2PLYP/6-31G(d) computed reaction profile, relative energies in kcal/mol.
Scheme 11: Gold-catalyzed cyclization of tethered alkynyl arylaldehydes.
Scheme 12: Gold-catalyzed cyclization of terminal diynes.
Scheme 13: Proposed hydrolysis/cyclization mechanism.
Scheme 14: Gold-catalyzed cyclization of internal diynes.
Scheme 15: Proposed solvolysis/cyclization mechanism.
Scheme 16: Gold-catalyzed cyclization of alkynyl epoxides and the 18O isotopic labeling experiment.
Scheme 17: Proposed oxygen transfer mechanism.
Scheme 18: Gold or silver-catalyzed cyclization of alkynyl epoxides and the corresponding deuterium labeling e...
