Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• formation of products 50–54 (Scheme 10). The ortho-acetoxylation of compounds containing picolinamide and quinoline-8-amine moieties (55 and 56, respectively) with the Pd(OAc)2/PhI(OAc)2 system in a AcOH/Ac2O mixture, resulting in the formation of products 57, 58, was performed at higher temperature (150 °C

• quinoline-8-amine directing moiety was used for copper-catalyzed aerobic ortho-aryloxylation and alkoxylation of arenes 59 with electron donating or electron withdrawing substituents to afford products 60 [66] (Scheme 12). The method is applicable to a wide range of OH-reagents; the molar ratio OH-reagent

One-pot four-component reaction for convenient synthesis of functionalized 1-benzamidospiro[indoline-3,4'-pyridines]

• Chao Wang,
• Yan-Hong Jiang and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2014, 10, 2671–2676, doi:10.3762/bjoc.10.281

• generation of Huisgen’s 1,4-dipoles are aromatic heterocycles such as N-alkylimidazole, pyridine, quinoline, isoquinoline and primary aromatic amines. In recent years, other nitrogen-containing nucleophiles such as hydrazine and arylhydrazines are also used to generate Huisgen’s 1,4-dipoles in domino

Tandem Cu-catalyzed ketenimine formation and intramolecular nucleophile capture: Synthesis of 1,2-dihydro-2-iminoquinolines from 1-(o-acetamidophenyl)propargyl alcohols

• Gadi Ranjith Kumar,
• Yalla Kiran Kumar,
• Ruchir Kant and
• Maddi Sridhar Reddy

Beilstein J. Org. Chem. 2014, 10, 1255–1260, doi:10.3762/bjoc.10.125

• compounds in moderate to good yields under mild reaction conditions. Keywords: alkyne; azide; cycloaddition; cyclization; quinoline; Introduction The synthesis of N-sulfonylketenimines via CuAAC (copper-catalyzed azide–alkyne cycloaddition) between terminal alkynes and sulfonyl azides has staged for a

• found that these 3o-propargyl alcohols were more productive compared to the above 2o-propargyl alcohols. Thus 2c–f were subjected to the standard reaction conditions with various sulfonyl azides to get the corresponding 4-alkyl-substituted quinoline derivatives 9j-o in 48–77% yields. In further

Addition of H-phosphonates to quinine-derived carbonyl compounds. An unexpected C9 phosphonate–phosphate rearrangement and tandem intramolecular piperidine elimination

• Łukasz Górecki,
• Artur Mucha and
• Paweł Kafarski

Beilstein J. Org. Chem. 2014, 10, 883–889, doi:10.3762/bjoc.10.85

• : aromatic quinoline and chiral aliphatic quinuclidine, and a hydroxy function on the stereogenic carbon atom. Such an architecture combined with the presence of nucleophilic and electrophilic centers buried in a hydrophobic environment predestinates the molecule to asymmetric applications, such as: chiral

• ’ protons of the quinoline system. This proximity is achievable only in the case of location of vinyl and quinoline protons at the same side of the double bond. Theoretical prediction of the H12 NMR chemical shift provided an additional confirmation [39]. The δ calculated for the Z arrangement (geminal

Aza-Diels–Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

• Amitabh Jha,
• Ting-Yi Chou,
• Zainab ALJaroudi,
• Bobby D. Ellis and
• T. Stanley Cameron

Beilstein J. Org. Chem. 2014, 10, 848–857, doi:10.3762/bjoc.10.81

• ; cyclization; Diels–Alder; inverse electron demand; N-acyliminium ion; tert-enamide; Introduction Fused indoline, isoindoline, quinoline and isoquinoline substructures are found in many natural products and bioactive synthetic compounds (Figure 1). For example, nuevamine is a naturally-occurring isoindolo[1,2

• ], and is used as a drug in Eastern Europe for the treatment of cerebrovascular disorders and age-related memory impairment [10]. We are interested in the isoindolo[2,1-a]quinoline skeleton (Figure 1) due to its structural similarities with these alkaloids. The most common method of synthesizing

• and strongly basic conditions [19]. Kang et al. achieved a highly enantioselective synthesis of an isoindolo[2,1-a]quinoline derivative by affecting an intramolecular ring closure on (E)-3-(2-(isoindolin-2-yl)phenyl)acrylaldehyde using camphorsulfonic acid and a chiral pyrrolidine organocatalyst [20

Copper–phenanthroline catalysts for regioselective synthesis of pyrrolo[3′,4′:3,4]pyrrolo[1,2-a]furoquinolines/phenanthrolines and of pyrrolo[1,2-a]phenanthrolines under mild conditions

• Rupankar Paira,
• Tarique Anwar,
• Maitreyee Banerjee,
• Yogesh P. Bharitkar,
• Shyamal Mondal,
• Sandip Kundu,
• Abhijit Hazra,
• Prakas R. Maulik and
• Nirup B. Mondal

Beilstein J. Org. Chem. 2014, 10, 692–700, doi:10.3762/bjoc.10.62

• the above catalytic system. To the best of our knowledge, this is the first report of the application of this catalyst for the regioselective 1,3-dipolar cycloaddition reaction, involving azomethine ylides derived from structurally complex quinoline-based N-heterocycles. Results and Discussion Our

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• synthetic strategy, a solution-phase parallel synthesis of 1,2-dihydroisoquinolines has been developed by Larock, providing a 105-membered library for biological assays [58]. Moreover, an extension to γ-ketoalkyne encompassed in diverse heterocyclic frameworks (quinoline, pyridine or benzo[b]thiophene) has

A catalyst-free multicomponent domino sequence for the diastereoselective synthesis of (E)-3-[2-arylcarbonyl-3-(arylamino)allyl]chromen-4-ones

• Pitchaimani Prasanna,
• Pethaiah Gunasekaran,
• Subbu Perumal and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2014, 10, 459–465, doi:10.3762/bjoc.10.43

• allows their application in the synthesis of important heterocycles such as indole [28], dihydropyridine [29], quinoline [30], pyrrole [31] and pyridinone [32]. Furthermore, they can take part in one-pot multicomponent reactions with both nucleophilic and electrophilic reactants, leading to a fast access

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• and quinoline derivatives, and nitro alcohols. Thus, part of the human life and life style is dependent of nitration as a unit reaction. In general, several types of nitrating agents are used for nitration. A literature search covering the last 50 years is presented in Figure 1. One third reports on

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• been reported by numerous authors. Among them, Zhao et al. [18] studied the coupling of non-activated aryl iodides with different alkenes using Pd-MCM-41-NH2. Other examples include Pd-FSM 16 (functionalised with pyridine-carboimine or quinoline-carboimine) [19], oxime carbapalladacycle anchored on

New syntheses of 5,6- and 7,8-diaminoquinolines

• Maroš Bella and
• Viktor Milata

Beilstein J. Org. Chem. 2013, 9, 2669–2674, doi:10.3762/bjoc.9.302

• coupling constants (J) are given in Hz. Elemental analyses were determined using a Thermo Finnigan Flash EA 1112 instrument. 6-Chloro-[1,2,5]selenadiazolo[3,4-h]quinoline (2). A mixture of selenadiazolo[3,4-h]quinolone 1 (5.0 g, 20.0 mmol) and POCl3 (10 mL, 16.4 g, 0.1 mol) was stirred at 90 °C for 15 min

• alkalisation of hydrochloride 5. [1,2,5]Selenadiazolo[3,4-h]quinoline (6). SeO2 (58.6 mg, 0.53 mmol) dissolved in water (1 mL) was added to a stirred solution of hydrochloride 5 (100 mg, 0.51 mmol) in water (1 mL) and stirring was continued for an additional 15 min at room temperature. Next, the reaction

• , 23.17. 9-Chloro-[1,2,5]selenadiazolo[3,4-f]quinoline (10). A mixture of selenadiazolo[3,4-f]quinolone 9 (2.0 g, 8.0 mmol) and POCl3 (4 mL, 6.56 g, 42.8 mmol) was stirred at 90 °C for 3 h. After the reaction was complete, the mixture was cooled to 0 °C in an ice bath followed by the addition of crushed

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• ] and neatly introduces the required chloride substituent at the 5-position. While isolated pyridines are a vital component in numerous drugs the related quinoline/quinolone scaffolds are becoming increasingly common. One such example is nalidixic acid (1.101, in fact a naphthyridone, Figure 2

Gold-catalyzed regioselective oxidation of propargylic carboxylates: a reliable access to α-carboxy-α,β-unsaturated ketones/aldehydes

• Kegong Ji,
• Jonathan Nelson and
• Liming Zhang

Beilstein J. Org. Chem. 2013, 9, 1925–1930, doi:10.3762/bjoc.9.227

• carboxylate; Introduction We reported in 2010 [1] that α-oxo gold carbenes could be conveniently generated as reactive intermediates in gold-catalyzed intermolecular oxidation of alkynes. By using pyridine N-oxides [1] and later 8-substituted quinoline N-oxides [2] as the external oxidants, this approach

Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues

• Xu-Wen Li,
• Jennifer Herrmann,
• Yi Zang,
• Philippe Grellier,
• Soizic Prado,
• Rolf Müller and
• Bastien Nay

Beilstein J. Org. Chem. 2013, 9, 1551–1558, doi:10.3762/bjoc.9.176

• class of compounds is characterized by a quinolone or quinoline nucleus substituted in position 3 or 4 by a farnesyl chain. In addition, aurachins can further be functionalized by biosynthetic oxidative processes [2][3][4][5]. Since then, additional members of this natural product family were discovered

• nonselectively oxidized products. The crude product 21a was then submitted to benzyl group hydrogenolysis. As expected upon completion of the reaction, the 4,5-dihydrofuro[3,2-c]quinoline N-oxide ring system 22 was obtained as a racemic pair of diastereoisomers in a 1:1 ratio, supposedly formed through the

• epoxidation conditions, i.e., the 4,5-dihydrofuro[2,3-c]quinoline N-oxide, and thus to synthesize chain analogues of 6. Biological investigations demonstrated the superiority of the natural product 4 regarding its inhibitory effect on Gram-positive bacteria, human cancer cell lines, and above all on the

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

• Todd J. Eckroat,
• Abdelrahman S. Mayhoub and
• Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

• (9) and diphenyl-1,3,4-oxadiazole (10); and thioflavin-T analogues such as benzothiazole (11), benzoxazole (12), benzofuran (13), imidazopyridine (14), and benzimidazole (15); as well as quinoline (16) and naphthalene (17) derivatives (Figure 1B). In this review, we provide an overview of these AD

• /g at 60 min). In vitro labeling of Aβ plaques in AD brain sections showed a strong signal with low background, and in vivo plaque labeling in transgenic mice was also successful. However, this scaffold is lacking in detailed SAR analysis compared to the imidazopyridine scaffold. Quinoline and

• naphthalene analogues Quinolines Investigation of the quinoline scaffold for imaging in AD has yielded some interesting results, despite there only being a few examples in the literature. The [18F]-labeled 2-fluoroquinolin-8-ol [18F]CABS13 (149) has recently been reported (Figure 5) [98]. The straightforward

Simple synthesis of pyrrolo[3,2-e]indole-1-carbonitriles

• Adam Trawczyński,
• Robert Bujok,
• Zbigniew Wróbel and
• Krzysztof Wojciechowski

Beilstein J. Org. Chem. 2013, 9, 934–941, doi:10.3762/bjoc.9.107

• ketone 5d upon reduction with SnCl2 cyclized to pyrrolo[3,2-f]quinoline-9-carbonitrile 7 [17]. The removal of the benzyloxymethyl group from 1-(benzyloxymethyl)pyrrolo[3,2-e]indoles by catalytic hydrogenation has been described by Macor [6]. The hydroxy group from the N-hydroxypyrrole fragment can be

3-Pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes, and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides, and ring contraction to cyanopyrroles and cyanoindoles

• Curt Wentrup,
• Nguyen Mong Lan,
• Adelheid Lukosch,
• Pawel Bednarek and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 743–753, doi:10.3762/bjoc.9.84

• -quinoline (44): The azide was sublimed at 80 °C and deposited with Ar at 22 K to form a matrix. Principal absorptions of the azide at 11 K: 2100, 1590, 1420, 1340, 1270, 1100 cm−1. Irradiation of the azide 44 at 308 nm or at 310–390 nm for 30 s afforded the nitrile ylide 47 together with a smaller amount of

• ascribed to 46 and reformation of the IR and UV–vis bands ascribed to the nitrile ylide 47. It was possible to cycle several times between these two species by using λ > 550 nm and λ = 310–390 nm, respectively (Figure 2 and Figure 3). FVT of 3-azido-2-phenyl-3-quinoline (44): (a) A sample of the azide (0.2

• g, 0.8 mmol) was sublimed at 60–80 °C and pyrolysed at 500 °C/10−4 mbar in the course of 3 h. The products were separated by flash chromatography on silica gel, eluting with chloroform. Indolo[3,2-b]quinoline (50) was obtained in 56–65% yield in different experiments: mp 250–251 °C (lit. [43] 248 °C

Synthesis of SF₅-containing benzisoxazoles, quinolines, and quinazolines by the Davis reaction of nitro-(pentafluorosulfanyl)benzenes

• Petr Beier and
• Tereza Pastýříková

Beilstein J. Org. Chem. 2013, 9, 411–416, doi:10.3762/bjoc.9.43

• observed compared to unsubstituted ortho-aminoacetophenone, but it could be overcome by using an excess of the condensation reagent and longer reaction times. Quinoline 12 was prepared in high yield by the Friedländer annulation reaction of 10a with excess ethyl acetoacetate in the presence of catalytic

• CAN using modified literature conditions (Scheme 3) [32]. Similarly, aminoketone 11a was condensed in good yield with cyclohexanone to provide quinoline 13 in good yield (Scheme 4). Finally, quinazoline 14 was synthesized by the reaction of aminoketone 11a with benzylamine in the presence of t-BuOOH

• Wipf and co-workers [29][30]. Synthesis of quinoline 12. Synthesis of quinoline 13. Synthesis of quinazoline 14. Synthesis of SF5-containing benzisoxazoles 7–9. Synthesis of ortho-aminobenzophenones 10 and 11. Supporting Information Supporting Information File 84: Experimental details

Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

• Yan Sun,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 8–14, doi:10.3762/bjoc.9.2

• three-component reaction of arylamine, isatin and cyclopentane-1,3-dione. Results and Discussion Recently we found that the four-component reactions of arylamine, acetylenedicarboxylate, isatin and dimedone in acetic acid resulted in the novel functionalized tetrahydrospiro[indoline-3,2’-quinoline

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

An efficient access to the synthesis of novel 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives

• Wentao Gao,
• Guihai Lin,
• Yang Li,
• Xiyue Tao,
• Rui Liu and
• Lianjie Sun

Beilstein J. Org. Chem. 2012, 8, 1849–1857, doi:10.3762/bjoc.8.213

• Wentao Gao Guihai Lin Yang Li Xiyue Tao Rui Liu Lianjie Sun Institute of Superfine Chemicals, Bohai University, Jinzhou 121000, China 10.3762/bjoc.8.213 Abstract An efficient access to the tetracyclic-fused quinoline systems, 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives 4a–l

• three-step route, offers easy access to tetracyclic-fused quinoline systems in short reaction times, and the products are obtained in moderate to good yields. Keywords: Eaton’s reagent; Friedel–Crafts acylation; Friedländer reaction; one-pot; PPA; quinoline; tetracyclic-fused; Introduction Polycyclic

• heterocycle-fused quinoline systems as important group compounds can be found in many biologically active natural products as well as in pharmacologically significant molecules, and have wide applications in medicinal chemistry [1][2][3][4]. It has been well-established that planar heterocycle-fused tri- or

A Wittig-olefination–Claisen-rearrangement approach to the 3-methylquinoline-4-carbaldehyde synthesis

• Mukund G. Kulkarni,
• Mayur P. Desai,
• Deekshaputra R. Birhade,
• Yunus B. Shaikh,
• Ajit N. Dhatrak and
• Ramesh Gannimani

Beilstein J. Org. Chem. 2012, 8, 1725–1729, doi:10.3762/bjoc.8.197

• Quinoline aldehydes are important synthetic intermediates in the synthesis of heterocyclic compounds that are used in the manufacturing of dyes [1] and pharmaceuticals [2][3]. 3-Substituted and 2,3-di-substituted quinoline-4-carbaldehyde derivatives are used in the synthesis of immunosuppressant KF20444 [4

• ] and 5-HT3 receptor antagonists [5]. Quinoline mevalonolactones, prepared from 3-methylquinoline-4-carbaldehyde, act as inhibitors of HMG-CoA reductase [6]. 3-Substituted quinoline-4-carbaldehyde derivatives are used in the development of molecular probes for the identification of extra interaction

• methods for the preparation of quinoline-4-carbaldehyde [12][13][14][15][16][17][18][19][20][21][22][23][24], only a few methods [6][9] are available for the preparation of 3-methylquinoline-4-carbaldehyde derivatives. In connection with the synthesis of camptothecin, we needed a general, high-yielding

Organocatalytic tandem Michael addition reactions: A powerful access to the enantioselective synthesis of functionalized chromenes, thiochromenes and 1,2-dihydroquinolines

• Chittaranjan Bhanja,
• Satyaban Jena,
• Sabita Nayak and
• Seetaram Mohapatra

Beilstein J. Org. Chem. 2012, 8, 1668–1694, doi:10.3762/bjoc.8.191

• reaction as the key step, reaction of aldehyde 56 with α,β-unsaturated aldehyde 57, catalyzed by chiral prolinol ethers Ie/HOAc in acetonitrile, provided quinoline derivative 58 with high yield and with high enantioselectivity (Scheme 29). In contrary to the work of Li, the presence of 4Å MS had a negative

Organocatalytic asymmetric addition of malonates to unsaturated 1,4-diketones

• Sergei Žari,
• Tiiu Kailas,
• Marina Kudrjashova,
• Mario Öeren,
• Ivar Järving,
• Toomas Tamm,
• Margus Lopp and
• Tõnis Kanger

Beilstein J. Org. Chem. 2012, 8, 1452–1457, doi:10.3762/bjoc.8.165

• the nucleophile to the tertiary amino group between the side chains of the catalysts. The re-face of the Michael acceptor is shielded by the flat quinoline unit and the si-attack of the malonate is preferred, affording R-selectivity (Figure 3). Determination of the absolute configuration The absolute

An intramolecular inverse electron demand Diels–Alder approach to annulated α-carbolines

• Zhiyuan Ma,
• Feng Ni,
• Grace H. C. Woo,
• Sie-Mun Lo,
• Philip M. Roveto,
• Scott E. Schaus and
• John K. Snyder

Beilstein J. Org. Chem. 2012, 8, 829–840, doi:10.3762/bjoc.8.93

• ], isolated from roots of the West African plant Cryptolepis sanguinolenta [7]. Cryptotackieine, a member of the indolo[2,3-b]quinoline class of heterocycles [8], has been shown to be a strong inhibitor of Plasmodium falciparum growth [9]. 2-Amino-α-carbolines have also been identified as mutagens produced in