نتایج جستجو برای: n substituted pyrrole

تعداد نتایج: 1009615  

Journal: :Chemical communications 2007
Kazuyuki Maeda Yuji Mito Tetsuya Yanagase Sarah Haraguchi Tsutomu Yamazaki Takeyuki Suzuki

Organosilyl groups were successfully incorporated in AFI and VFI aluminophosphate frameworks using organoalkoxysilanes to modify hydrophobicity and acidity of the molecular sieves.

Journal: :Organic letters 2010
Balaji Purushothaman Sean R Parkin John E Anthony

The synthesis of new silylethyne-substituted hexacene derivatives to investigate their solubility, stability, and pi-stacking is reported. It was found that "butterfly" dimerization, rather than photooxidation, is the dominant decomposition pathway for these molecules and that stability can be enhanced by functionalization to prevent close contact between specific regions of the aromatic core. ...

Journal: :Dalton transactions 2004
Stephan Hartmann Rainer F Winter Biprajit Sarkar Falk Lissner

Pyrrolyl and indolyl substituted allenylidene complexes of ruthenium have been prepared from the trapping of cationic trans-[Cl(dppm)(2)Ru=C=C=C=CH(2)](+) with various pyrroles or N-methylindole. The reaction is rationalized as involving regioselective attack of the organometallic electrophile on the electron-rich heterocycle followed by proton migration to the terminal =CH(2) entity of the int...

Journal: :The Journal of organic chemistry 2001
Y Chen C J Medforth K M Smith J Alderfer T J Dougherty R K Pandey

To investigate the effects of electron-donating and electron-withdrawing substituents upon the reaction of porphyrins with osmium tetraoxide, and the pinacol-pinacolone rearrangement of the resulting diols, a series of meso-substituted porphyrins were prepared by total synthesis. Porphyrins with electron-donating substitutents at the meso-positions gave vic-dihydroxychlorins in which the adjace...

Journal: :European Journal of Organic Chemistry 2022

Easy accessible isoxazol-5(4 H )-ones are useful precursors of heterocycles. In this context we report the ruthenium-catalyzed transformation 4-alkenyl-substituted isoxazol-5-ones to afford 1 -pyrrole derivatives. The operative conditions were proven be effective also on cyclohexane-fused isoxazolones giving 4,5,6,7-tetrahydroindoles. Reactions, which allow access tri-and tetra-substituted pyrr...

Journal: :Chemistry, an Asian journal 2013
Yoshiaki Miyamoto Norihiro Wada Takahiro Soeta Shuhei Fujinami Katsuhiko Inomata Yutaka Ukaji

The stereoselective direct transformation of N-(propargylic)hydroxylamines into cis-2-acylaziridines was achieved by the combined use of AgBF4 and CuCl. Copper salts were found to promote the transformation of the intermediary 4-isoxazolines into 2-acylaziridines and both 3-aryl- and 3-alkyl-substituted 2-acylaziridines could be prepared by using this method. Furthermore, subsequent 1,3-dipolar...

Journal: :Dalton transactions 2008
Gareth W Bates Philip A Gale Mark E Light Mark I Ogden Colin N Warriner

Metal complexes of 2,5-dicarboxamidopyrroles and 2,5-dicarbothioamidopyrroles have been structurally characterised for the first time, complementing the significant amount of work that has been reported for the analogous pyridine ligands. N,N'-Bis(3,5-dinitrophenyl)-3,4-diphenyl-1H-pyrrole-2,5-dicarboxamide forms octahedral bis(tridentate) complexes with cobalt(III) and nickel(II), where the li...

2013
Sudipta Pathak Kamalesh Debnath Animesh Pramanik

A convenient and efficient methodology for the synthesis of densely substituted pyrrole-fused isocoumarins, which employs solid-supported silica sulfuric acid (SSA) as catalyst, has been developed. When the mixture of ninhydrin adducts of acetylacetone/ethyl acetoacetate and primary amines was heated on the solid surface of SSA under solvent-free conditions, the pyrrole-fused isocoumarins were ...

2011
Elena Borsini Gianluigi Broggini Andrea Fasana Chiara Baldassarri Angelo M Manzo Alcide D Perboni

In a simple procedure, the intramolecular hydroarylation of N-propargyl-pyrrole-2-carboxamides was accomplished with the aid of gold(III) catalysis. The reaction led to differently substituted pyrrolo[2,3-c]pyridine and pyrrolo[3,2-c]pyridine derivatives arising either from direct cyclization or from a formal rearrangement of the carboxamide group. Terminal alkynes are essential to achieve bicy...

Journal: :Magnetic resonance in chemistry : MRC 2008
Lenka Grycová Dagmar Hulová Lukás Maier Stanislav Standara Marek Necas Filip Lemière Radovan Kares Jirí Dostál Radek Marek

Adducts of the quaternary protoberberine alkaloids (QPA) berberine, palmatine, and coptisine were prepared with nucleophiles derived from pyrrole, pyrazole, imidazole, and 1,2,4-triazole. The products, 8-substituted 7,8-dihydroprotoberberines, were identified by mass spectrometry and 1D and 2D NMR spectroscopy, including (1)H--(15)N shift correlations at natural abundance. In addition, two addu...

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