Papers

With Tag: Heterocyclic Compounds (more Than One Hetero Atom)

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Synthesis of Fluorous and Nonfluorous Polycyclic Systems by One-Pot, Double Intramolecular 1,3-Dipolar Cycloaddition of Azomethine Ylides

Yimin Lu, Steven Geib, Wei Zhang
Org. Lett. | 2005 | 10.1021/ol0507773

Under microwave irradiation, a one-pot, double intramolecular [3 + 2]-cycloaddition reaction of azomethine ylides leads to formation of a novel hexacyclic ring system. The major diastereomer is isolated, and its stereochemistry is determined by X-ray crystal...

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Nickel-Catalyzed Direct Arylation of Azoles with Aryl Bromides

Masahiro Miura, Hitoshi Hachiya, Tetsuya Satoh, Koji Hirano
Org. Lett. | 2009 | 10.1021/ol900159a

Nickel catalyst systems for the direct C2 arylation of oxazoles and thiazoles have been developed. The catalyst systems are cost-efficient and allow the use of various aryl bromides in the C−H arylation of azoles.

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Isoxazole → Benzisoxazole Rearrangement Promoted Cascade Reactions Affording Stereodefined Polycycles

Hidehiro Uesuka, Keisuke Suzuki, Jeffrey W. Bode
Org. Lett. | 2003 | 10.1021/ol0272848

A new chemo-, regio-, and stereoselective cascade reaction features a novel isoxazole → benzisoxazole rearrangement and affords highly functionalized, differentially protected compounds. The products of this reaction are directly converted to a number of...

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Cobalt- and Iron-Catalyzed Redox Condensation of o-Substituted Nitrobenzenes with Alkylamines: A Step- and Redox-Economical Synthesis of Diazaheterocycles

Ludmila Ermolenko, Julie Le Bescont, Ali Al-Mourabit, Thanh Binh Nguyen
Org. Lett. | 2013 | 10.1021/ol403064z

A wide variety of functionalized 2-aryl benzimidazoles can be prepared by a solvent-free cobalt- or iron-catalyzed redox condensation of 2-nitroanilines and benzylamines. The cascade including benzylamine oxidation, nitro reduction, condensation, and...

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Stereoselective Synthesis of Protected 1,2-Diols and 1,2,3-Triols by a Tandem Hydroboration−Coupling Sequence

Manmohan Kapur, Martin E. Maier, Anton Khartulyari
Org. Lett. | 2006 | 10.1021/ol0602194

A new approach to complex chiral diols and polyols is described utilizing a tandem hydroboration/Suzuki cross-coupling reaction. This method utilizes the versatility of a glycolate-derived chiral template.

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Cyclic Sulfamidates as Vehicles for the Synthesis of Poly- and Diversely Substituted Benzosultams via Unusual S(O)2−O Bond Cleavage

Eric Deniau, Axel Couture, Magali Lorion, Vangelis Agouridas, Pierre Grandclaudon
Org. Lett. | 2010 | 10.1021/ol100288k

1,2-Cyclic sulfamidates undergo novel, efficient, and regiospecific intramolecular nucleophilic cleavage with aryllithiated species to provide an entry to poly-, diversely, and enantiopure N-substituted benzosultams.

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Palladium-Catalyzed Direct C–H Bond Alkynylations of Heteroarenes Using gem-Dichloroalkenes

Lutz Ackermann, Yingjun Zhu, Christoph Kornhaass
Org. Lett. | 2012 | 10.1021/ol300514d

Palladium-catalyzed direct alkynylations of heteroarenes were accomplished with inexpensive gem-dichloroalkenes as user-friendly electrophiles, which set the stage for a modular, step-economical synthesis of diversely decorated heteroaryl alkynes with ample...

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A Modular Sydnone Cycloaddition/Suzuki−Miyaura Cross-Coupling Strategy to Unsymmetrical 3,5-Bis(hetero)aromatic Pyrazoles

Nuno Monteiro, Jean-Pierre Vors, Geneviève Balme, Pierre Genix, Mazen Es-Sayed, Thierry Delaunay
Org. Lett. | 2010 | 10.1021/ol101087j

The [3 + 2] dipolar cycloaddition of 4-halosydnones with 1-haloalkynes opens a straightforward access to 3,5-dihalopyrazoles, valuable scaffolds for the elaboration of unsymmetrically 3,5-substituted pyrazole derivatives via site-selective Pd-catalyzed...

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Enantioselective Synthesis of a Dual Orexin Receptor Antagonist

Ian K. Mangion, Benjamin D. Sherry, Jingjun Yin, Fred J. Fleitz
Org. Lett. | 2012 | 10.1021/ol3014123

A concise, enantioselective synthesis of the potent dual orexin inhibitor suvorexant (1) is reported. Key features of the synthesis include a mild copper-catalyzed amination, a highly chemoselective conjugate addition, and a tandem enantioselective...

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Synthesis of 3-Substituted Indazoles from Arynes and N-Tosylhydrazones

Pan Li, Richard C. Larock, Feng Shi, Jingjing Zhao, Chunrui Wu
Org. Lett. | 2011 | 10.1021/ol201086g

Readily available, stable, and inexpensive N-tosylhydrazones react with arynes under mild reaction conditions to afford 3-substituted indazoles in moderate to good yields. The reaction appears to involve a dipolar cycloaddition of in situ generated diazo...

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Generation of Nitrile Oxides from Oximes Using t-BuOI and Their Cycloaddition

Satoshi Minakata, Youhei Takeda, Toshiki Nagamachi, Sota Okumura
Org. Lett. | 2011 | 10.1021/ol2010616

tert-Butyl hypoiodite (t-BuOI) was found to be a powerful reagent for the cycloaddition of oximes and alkenes/alkynes, leading to the formation of a variety of isoxazolines or isoxazoles under mild conditions.

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Catalytic Generation of Cesium Acetylide by CsF: Synthesis of 1,3-Benzothiazines from Cyclic Sulfenamides

Vincent Reboul, Cédric Spitz, Patrick Metzner, Jean-François Lohier
Org. Lett. | 2009 | 10.1021/ol9009333

An efficient synthesis of enantiopure 1,3-benzothiazines has been achieved by reaction of cyclic sulfenamides and alkylpropiolate or tosylacetylene catalyzed by cesium fluoride.

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Enantioselective Intramolecular Formal [2 + 4] Annulation of Acrylates and α,β-Unsaturated Imines Catalyzed by Amino Acid Derived Phosphines

Rakesh Ganguly, Yonggui Robin Chi, Zhichao Jin, Yu Du, Ruojie Yang, Bhoopendra Tiwari
Org. Lett. | 2012 | 10.1021/ol3013588

The first chiral phosphine-catalyzed activation of acrylates for intramolecular formal [2 + 4] reactions with unsaturated imines is described. The catalytic reactions afford N-heterocycles with exceptionally high diastereo- and enantioselectivities. The [2 +...

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Microwave-Assisted Fluorination of 2-Acylpyrroles: Synthesis of Fluorohymenidin

Thomas Lindel, Benjamin Troegel
Org. Lett. | 2011 | 10.1021/ol2029993

Treatment of mono- and nonbrominated 2-acylpyrroles with Selectfluor under microwave conditions leads to fluorination of the pyrrole ring in the 5-position. In particular, 2-trichloroacetylated pyrrole can be fluorinated. As an example, dihydrofluorohymenidin...

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Synthesis of 2-Imidazolones and 2-Iminoimidazoles

Carl J. Lovely, Heather M. Lima
Org. Lett. | 2011 | 10.1021/ol2022438

Convenient methods for the direct conversion of imidazolium salts to the corresponding 2-imidazolone or 2-imino imidazole derivatives have been developed. Treatment of the salt with commercial bleach leads to effective oxidation at C2 and the formation of the...

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Practical Synthesis of 1-Aryl-6-(hydroxymethyl)-2-ketopiperazines via a 6-exo Amide−Epoxide Cyclization

Daniel D. Holsworth, Wayne L. Cody, Noel A. Powell, Jeremy J. Edmunds, Emma C. Clay, Peter G. Blazecka, Dennis M. Downing, Fred L. Ciske
Org. Lett. | 2004 | 10.1021/ol048235t

Chiral 1-aryl-6-(hydroxymethyl)-2-ketopiperazines can be prepared via an operationally simple, 6-exo epoxide ring-opening cyclization to form the ketopiperazine C6−N1 bond in high yields and with excellent enantiomeric purity.

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Intramolecular Cycloaddition Reactions of Silyl Nitronate Tethered to Vinylsilyl Group:  2-Nitroalkanols as Precursors for Amino Polyols

Seiki Saito, Yoshihiro Shimizu, Teruhiko Ishikawa, Takayuki Kudoh
Org. Lett. | 2003 | 10.1021/ol035423v

A method for converting 2-nitroalkanols to precursors for stereodefined amino polyols is described. Diphenylvinylsilylation of the 2-nitroalkanols' hydroxy groups and subsequent silyl nitronate generation by using TMS-Cl and Et 3 N in CH 3 CN at 0 °C to room...

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Samarium Barbier Reactions of α-Iodomethyloxazoles and Thiazoles with Aliphatic Aldehydes

Michael P. Clark, David R. Williams, Partha P. Nag, Bryan W. Stroup, Martin A. Berliner
Org. Lett. | 2005 | 10.1021/ol051345v

The reductive coupling of substituted α-iodomethyloxazoles and thiazoles with aliphatic aldehydes under Barbier conditions provides an effective method for the direct incorporation of intact heterocyclic systems.

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Copper-Catalyzed Intramolecular Cyclization to N-Substituted 1,3-Dihydrobenzimidazol-2-ones

Hongbin Sun, Hong Liu, Hualiang Jiang, Zhaoguang Li
Org. Lett. | 2008 | 10.1021/ol8011106

An efficient and convenient method was developed for preparing N-substituted 1,3-dihydrobenzimidazol-2-ones from N′-substituted N-(2-halophenyl)ureas via a CuI/DBU-catalyzed cyclization in DMSO under microwave heating. High yields were obtained and a...

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A New β-Carbolinone Synthesis Using a Rh(II)-Promoted [3 + 2]-Cycloaddition and Pd(0) Cross-Coupling/Heck Cyclization Chemistry

Albert Padwa, Joel M. Harris
Org. Lett. | 2003 | 10.1021/ol0356338

A short and efficient synthesis of the β-carbolinone ring system was achieved using a rhodium(II)-catalyzed [3 + 2]-cycloaddition, a Pd(0)-catalyzed C−N amination reaction, and a subsequent intramolecular Heck reaction as the key synthetic steps.

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