نتایج جستجو برای: pyrroles

تعداد نتایج: 1881  

Journal: :Organic letters 2006
Jeffrey D Winkler Justin R Ragains

Irradiation of vinylogous amide or imide 5 (R = H, alkyl, or Ac) leads to the selective formation of either crossed photoadduct 7 (R = Ac) or parallel photoadduct 8 (R = H or alkyl) as a function of the nature of the group R. The latter result leads to a novel approach to the synthesis of pyrroles, that is, 8'.

Journal: :Chemical communications 2015
Julian Wippich Ingo Schnapperelle Thorsten Bach

A total of 19 alkylated heterocycles (thiophenes, benzothiophenes, pyrroles, furans) were prepared (36-99% yield) from the respective pyridin-2-yl-substituted precursors employing alkylboronic acids as the C-H alkylating reagents in an oxidative (Ag2CO3 and 2,6-dimethyl-1,4-benzoquinone as oxidants) Pd-catalysed coupling reaction.

Journal: :Chemical communications 2014
Jia Meng Yi-Jin Li Yu-Long Zhao Xiu-Bin Bu Qun Liu

A base-catalyzed cycloisomerization of 5-cyano-pentyne bearing a terminal alkyne group has been developed under metal-free conditions. This reaction involves a tandem process providing efficient access to 3-cyano-4,5-dihydro-1H-pyrroles in good to excellent yields in an atom-economic manner with 1,3-cyano migration as the key transformation.

Journal: :Dalton transactions 2008
Julien Bachmann Thomas S Teets Daniel G Nocera

The reaction of zirconium(IV) porphyrinogen with water yields a dinuclear complex in which one mu-oxo ligand bridges two Zr(IV) centres, and two protons are bound to the alpha carbons of two porphyrinogen pyrroles. The reaction establishes the utility of the porphyrinogen macrocycle as a storage site for protons as well as electrons.

Journal: :Journal of the American Chemical Society 2004
David Tejedor David González-Cruz Fernando García-Tellado José Juan Marrero-Tellado Matías López Rodríguez

A new microwave-assisted rearrangement of 1,3-oxazolidines scaffolds is the basis for a new, metal-free, direct, and modular construction of tetrasubstituted pyrroles from terminal-conjugated alkynes, aldehydes, and primary amines. This new reaction manifold entails two linked domino processes in a one-pot manner with both atom- and bond-efficiency and under very simple and environment-friendly...

Journal: :Chemical communications 2012
Jingchao Feng Wenjin Yan Dong Wang Peng Li Quantao Sun Rui Wang

The first asymmetric aza-Friedel-Crafts reaction of indoles and pyrroles with isatin-derived N-Boc ketimines catalyzed by chiral phosphoric acids is reported. In general, derivatives of substituted 3-amino-2-oxindoles were obtained with excellent enantioselectivities and high yields.

Journal: :Tetrahedron letters 2007
Mohammed Abid Liliana Teixeira Béla Török

A novel one-pot synthesis of N-substituted heterocycles via successive cyclization/annelation starting from primary sulfonamides is described. This process leads directly to N-sulfonyl pyrroles, indoles and carbazoles. The selection of appropriate reactant/triflic acid ratio successfully controls the formation of the desired product.

Journal: :The Journal of organic chemistry 2007
Liangbo Zhu Peng Guo Gaocan Li Jingbo Lan Rugang Xie Jingsong You

Relatively mild and highly efficient CuI-catalyzed N-arylation procedures for nitrogen-containing heterocycles (e.g., imidazoles, benzimidazoles, pyrroles, pyrazoles, indoles, triazoles, etc.) with aryl and heteroaryl halides have been developed. The protocols can be performed easily and tolerate a number of functional groups, such as ester, nitrile, nitro, ketone, free hydroxyl, and free prima...

2010
S. Ourahou M. Chammache H. Zouihri El Mokhtar Essassi Seik Weng Ng

The title compound, C(16)H(18)N(2)O(5), consists of a benzodiazepinedione system fused to a pyrrole system. The seven-membered ring adopts a boat-shaped conformation (with the methine C atom as the prow); the five-membered ring adopts an enveloped-shaped conformation (with the hydr-oxy-bearing C atom as the flap). The hydr-oxy group is hydrogen bonded to the carbonyl O atom of an adjacent mol-e...

Journal: :Canadian Journal of Chemistry 1969

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