A novel and facile synthesis of 3-(2-benzofuroyl)- and 3,6-bis(2-benzofuroyl)carbazole derivatives

• Wentao Gao,
• Meiru Zheng and
• Yang Li

Beilstein J. Org. Chem. 2011, 7, 1533–1540, doi:10.3762/bjoc.7.180

• benzofuroyl-based compounds [39][40][41][42][43]. We have recently reported the synthesis of quinolyl-substituted carbazoles [44] and benzofuranyl-substituted quinoline [45]. Thus, in light of the above findings and in the context of our ongoing work on the synthesis of new heterocyclic compounds, we found it

Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

• Paul Knochel,
• Matthias A. Schade,
• Sebastian Bernhardt,
• Georg Manolikakes,
• Albrecht Metzger,
• Fabian M. Piller,
• Christoph J. Rohbogner and
• Marc Mosrin

Beilstein J. Org. Chem. 2011, 7, 1261–1277, doi:10.3762/bjoc.7.147

• -group are able to direct the zincation. Thus, the diiodoquinoline 22 is regioselectively zincated (25 °C, 12 h) to intermediate 23 leading to the polyfunctional quinoline 24 in 78% yield after copper(I)-mediated acylation (Scheme 4 and Supporting Information File 1, Procedure 1) [8]. This

• exchange reaction for the regioselective functionalization of quinolines. Thus, the 2,3-dibromoquinoline (65) is regioselectively converted to the 3-magnesiated quinoline derivative 66. Using the same exchange reagent, iPrMgCl·LiCl (64) and 2,4-dibromoquinoline (68), it is now possible to obtain the 4

• -magnesiated quinoline 69. All these magnesiations proceed at low temperature (−50 °C to −78 °C) and are complete within 2 h reaction time. After reaction with TsCN, the corresponding nitriles 67 and 70 were obtained in 84–85% yield (Scheme 12 and Supporting Information File 1, Procedure 5) [36]. The rate of

Multicomponent reaction access to complex quinolines via oxidation of the Povarov adducts

• Esther Vicente-García,
• Rosario Ramón,
• Sara Preciado and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2011, 7, 980–987, doi:10.3762/bjoc.7.110

• tetrahydroquinolines obtained through the Povarov multicomponent reaction have been oxidized to the corresponding quinoline, giving access to a single product through a two-step sequence. Several oxidizing agents were studied and manganese dioxide proved to be the reagent of choice, affording higher yields, cleaner

• reactions and practical protocols. Keywords: manganese dioxide; multicomponent reactions; oxidation; Povarov; quinolines; tetrahydroquinolines; Introduction Heterocycles are ubiquitous scaffolds in pharmaceuticals, natural products and biologically active compounds. Quinoline systems in particular

• , Thompson et al. described the oxidation of fused pyrrolohydroquinolines (type 6) using MnO2 obtained from batteries. A kinetic competition between two processes was observed, and the desired double oxidation to the corresponding fused quinoline 7 took place, along with the oxidation–elimination sequence

Gold-catalyzed regioselective oxidation of terminal allenes: formation of α-methanesulfonyloxy methyl ketones

• Yingdong Luo,
• Guozhu Zhang,
• Erik S. Hwang,
• Thomas A. Wilcoxon and
• Liming Zhang

Beilstein J. Org. Chem. 2011, 7, 596–600, doi:10.3762/bjoc.7.69

• ][13][14][15][16][17] or via allenes generated in situ [18][19][20][21]. We have recently shown that highly reactive gold carbenes can be generated from alkynes via gold-promoted intermolecular oxidation by pyridine/quinoline N-oxides [22][23][24][25], making benign alkynes effective surrogates of

First synthesis of 2-(benzofuran-2-yl)-6,7-methylene dioxyquinoline-3-carboxylic acid derivatives

• Wentao Gao,
• Jia Liu,
• Yun Jiang and
• Yang Li

Beilstein J. Org. Chem. 2011, 7, 210–217, doi:10.3762/bjoc.7.28

• Wentao Gao Jia Liu Yun Jiang Yang Li Institute of Superfine Chemicals, Bohai University, Jinzhou 121000, China 10.3762/bjoc.7.28 Abstract A facile and inexpensive synthesis of a series of novel methylenedioxy-bearing 2-(benzofuran-2-yl)-quinoline-3-carboxylic acid derivatives 3a–h via the one-pot

• ; methylenedioxy-bearing; one-pot; quinoline-3-carboxylic acid; salicylaldehyde; Introduction Heterocyclic systems containing a quinoline nucleus are an important group of compounds in medicinal chemistry, and are ubiquitous sub-structures associated with biologically active natural products [1][2][3][4]. Some

• quinoline compounds especially those containing heterocyclic systems at 2-position have been shown to display a wide spectrum of biological activities such as cytotoxic, anti-inflammatory and antifungal behavior [5][6]. For example, 2-(furan-2-yl)quinoline-4-carboxylic acid (and analogues) (1, Figure 1) was

Synthesis of 3-(quinolin-2-yl)- and 3,6-bis(quinolin-2-yl)-9H-carbazoles

• Yang Li and
• Wentao Gao

Beilstein J. Org. Chem. 2010, 6, 966–972, doi:10.3762/bjoc.6.108

• : acetylcarbazole; β-aminoaldehyde; β-aminoketone; Friedländer condensation; sodium ethoxide; Introduction Nitrogen-containing heterocycles are a very important group of organic compounds because of their wide application in medicine, agriculture, and technology. Among these, quinoline and carbazole derivatives

• are of significant synthetic interest due to their diverse range of biological activities. Compounds containing a quinoline framework have been found applications as pharmaceuticals and agrochemicals, as well as being general synthetic building blocks [1][2][3]. Industrial, biological, and synthetic

• significance places this scaffold in a prestigious position. Studies on new quinoline derivatives appear frequently in the chemical literature. Therefore, significant effort continues to be directed toward the development of new quinolines . In particular, there is much current interest in the quinoline ring

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• heterocyclic compounds using trifluoromethylthiocopper (Scheme 23). The reaction is carried out by heating in a polar solvent (e.g. DMF, quinoline or N-methyl pyrrolidone) and the substrate can contain electron-donating or electron-withdrawing groups. Electron-withdrawing groups activate the iodo atom and

Synthesis of gem-difluoromethylenated analogues of boronolide

• Jing Lin,
• Xiao-Long Qiu and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2010, 6, No. 37, doi:10.3762/bjoc.6.37

• attempts to convert the triple bond in compound 12a into the cis double bond via hydrogenation in the presence of Lindlar catalyst were unsuccessful. Even with the addition of quinoline, these reactions only resulted in inseparable mixtures. Fortunately, hydrogenation proceeded well by means of Pd–BaSO4

• –quinoline system [26], leading to the expected alcohol 13a in 96% yield. Subsequent selective removal of the primary TBS group in 13a with D-camphor-10-sulfonic acid (CSA) yielded the diol 14a in 80% yield. As expected, treatment of compound 14a with 0.2 equiv of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO

Fused bicyclic piperidines and dihydropyridines by dearomatising cyclisation of the enolates of nicotinyl-substituted esters and ketones

• Heloise Brice,
• Jonathan Clayden and
• Stuart D. Hamilton

Beilstein J. Org. Chem. 2010, 6, No. 22, doi:10.3762/bjoc.6.22

• : bicyclic; cyclisation; dearomatisation; enol ether; heterocycle; pyridine; quinoline; Introduction Oxidative [1][2][3] or reductive (nucleophilic) [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] dearomatising cyclisation reactions are effective strategies for rapidly building complexity

An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III) ions

• Markus Albrecht,
• Olga Osetska,
• Thomas Abel,
• Gebhard Haberhauer and
• Eva Ziegler

Beilstein J. Org. Chem. 2009, 5, No. 78, doi:10.3762/bjoc.5.78

• peptidic scaffold and the final ligand 1a-H3 is obtained in good yield (90%). Successive Cope rearrangement of the spacers to the 5-position of the quinoline moiety is not observed under the chosen reaction conditions. 1H NMR spectra of 4 and 1a-H3 show pronounced differences for the resonances of the 8

Regioselective alkynylation followed by Suzuki coupling of 2,4-dichloroquinoline: Synthesis of 2-alkynyl- 4-arylquinolines

• Ellanki A. Reddy,
• Aminul Islam,
• K. Mukkanti,
• Venkanna Bandameedi,
• Dipal R. Bhowmik and
• Manojit Pal

Beilstein J. Org. Chem. 2009, 5, No. 32, doi:10.3762/bjoc.5.32

• -dichloroquinoline; palladium; water; Introduction 2-Alkynyl pyridine and its benzo (i.e. quinoline) derivative possessing an aryl group at the C-4 position (A, Figure 1) have attracted considerable interest due to their utility in the development of compounds of potential pharmacological interest [1][2][3]. 2

• -Alkenyl/alkynylquinolines, have been reported to possess anti-retroviral properties [4]. Only few methods are known for the synthesis of A. Considering the possible C–C bond forming reactions on a pyridine/quinoline ring (Figure 1), the synthesis of A can be carried out following two main strategies e.g

• . (a) arylation at C-4 followed by alkynylation at C-2 or (b) alkynylation at C-2 followed by arylation at C-4. Methodologies based on strategy ‘a’ have been reported earlier. For example, Sonogashira coupling of a terminal alkyne with 2-chloro-4-aryl substituted quinoline [3] in the presence of (PPh3

Quinoline based receptor in fluorometric discrimination of carboxylic acids

• Kumaresh Ghosh,
• Suman Adhikari,
• Asoke P. Chattopadhyay and
• Purnendu Roy Chowdhury

Beilstein J. Org. Chem. 2008, 4, No. 52, doi:10.3762/bjoc.4.52

• Kumaresh Ghosh Suman Adhikari Asoke P. Chattopadhyay Purnendu Roy Chowdhury Department of Chemistry, University of Kalyani, Kalyani, Nadia-741235, India Chembiotek Research International Pvt. Ltd., Salt Lake City, Kolkata-700 091, India 10.3762/bjoc.4.52 Abstract Quinoline and naphthalene-based

• value and did not form any excimer upon complexation with the same acids under similar conditions. This established the role of quinoline ring nitrogen in binding with the acids. Keywords: carboxylic acid recognition; excimer emission; naphthalene; quinoline; Introduction The sensing and monitoring of

• - and dicarboxylic acids by a large number of receptors of different architectures is known [11][12][13][14]. We have also reported a series of synthetic receptors for carboxylic acids of various types [15][16][17][18]. In continuation, we report here a new quinoline based sensor 1 (Figure 1) which is

New modification of the Perkow reaction: halocarboxylate anions as leaving groups in 3-acyloxyquinoline- 2,4(1H,3H)-dione compounds

• Oldřich Paleta,
• Karel Pomeisl,
• Stanislav Kafka,
• Antonín Klásek and
• Vladislav Kubelka

Beilstein J. Org. Chem. 2005, 1, No. 17, doi:10.1186/1860-5397-1-17

• 72 Zlín, Czech Republic Zentiva, U Kabelovny 130, 10237 Prague 10, Czech Republic 10.1186/1860-5397-1-17 Abstract Substituted 3-(fluoroacyloxy)quinoline-2,4(1H,3H)-diones including 3-(fluoroiodoacetoxy) derivatives react with triethyl phosphite to afford either the product of the Perkow reaction or

• the corresponding 4-ethoxyquinolin-2(1H)-one. In both reactions, the fluorocarboxylate anion acts as the first observed leaving group. This observation restricts the application of the intramolecular Horner-Wadsworth-Emmons synthesis to modify quinoline-2,4(1H,3H)-diones by the annulation of

• the sugar skeleton and its multiple acetoxy groups. In this communication we would like to report on the ability of halocarboxylate anions to act as leaving groups in the reactions of 3-(haloacyloxy)-quinoline-2,4(1H,3H)-diones with triethyl phosphite to afford 8 and 9, the products of the Perkow