نتایج جستجو برای: heterocyclic

تعداد نتایج: 9423  

Journal: :Dalton transactions 2010
George C Fortman Alexandra M Z Slawin Steven P Nolan

The use of two metal systems cis-Pt(NHC)(2)Me(2) and cis-Ir(NHC)(CO)(2)Cl help to highlight the flexibility of a series of cycloalkyl-substituted N-heterocyclic carbene ligands (ICy, ICy(7), ICy(8), ICy(12)). Bond dissociation enthalpies of several N-heterocyclic carbenes (NHCs) in cis-Pt(NHC)(2)Me(2) are estimated. Electronic and steric parameters of the ICy(n) ligands are quantified and discu...

2016
Belakavadi K. Sagar Hemmige S. Yathirajan Jerry P. Jasinski Christopher Glidewell

In the title compound, C15H12N4O4, the dihedral angle between the heterocyclic rings is 12.60 (8)°, and that between the benzene ring and the adjacent heterocyclic ring is 85.14 (6)°. In the crystal, a combination of N-H⋯O and O-H⋯O hydrogen bonds link mol-ecules related by a glide plane into a C(5) C(6)[R (2) 2(9)] chain of rings, which is a distinctly different packing motif to those observed...

2017
Walid Fathalla Ibrahim A I Ali Pavel Pazdera

In this paper, we introduce a novel and convenient method for the transformation of heterocyclic amides into heteocyclic thioamides. A two-step approach was applied for this transformation: Firstly, we applied a chlorination of the heterocyclic amides to afford the corresponding chloroheterocycles. Secondly, the chloroherocycles and N-cyclohexyl dithiocarbamate cyclohexylammonium salt were heat...

Journal: :Molecules 2010
Yan Zhang Xin Li Chih-Kang Lo Shun-Tang Guo

In this study, the flavor substances of soypaste were extracted by a simultaneous distillation method and identified by GC-MS. The characteristic aroma components of soypaste were determined by the GC-O technique and the FD value of the characteristic aroma components was determined by AEDA method. It could be inferred that the aroma of the soypaste should be attributed to the presence of heter...

Journal: :Chemical communications 2015
M Therkelsen M T Rasmussen A T Lindhardt

Two decarboxylative methods providing access to N-alkylated α-trihalomethylated heterocyclic amines have been developed. A batch protocol in which methyl trifluoroacetate acts both as a methylating reagent and subsequently as a nucleophilic trifluoromethyl anion precursor upon its addition to (iso)quinoline derivatives. Next, a telescoped continuous flow process, forming the corresponding α-tri...

Journal: :Chemistry 2012
Prakash T Parvatkar Perunninakulath S Parameswaran Santosh G Tilve

Heterocyclic scaffolds represent the key structural subunits of many biologically active compounds. Over the last few years iodine-mediated reactions have been extensively studied due to their low cost and eco-friendliness. This Review covers advances in the field of iodine-mediated synthesis of heterocyclic compounds since 2006, especially with an emphasis on mechanisms of ring formation. In t...

Journal: :Journal of the American Chemical Society 2014
Ming Wang Zhijian Huang Jianfeng Xu Yonggui Robin Chi

The first N-heterocyclic carbene (NHC)-catalyzed [3+4] cycloaddition of azomethine imines and enals is disclosed. Oxidative catalytic remote activation of enals affords 1,4-dipolarophile intermediates that react with 1,3-dipolar azomethine imines to generate dinitrogen-fused seven-membered heterocyclic products with high optical purities. Our approach also provides effective kinetic resolution ...

Journal: :Organic & biomolecular chemistry 2014
Huamin Wang Hui Chen Ya Chen Guo-Jun Deng

The palladium catalytic system was first applied to 2-arylquinazoline synthesis via hydrogen transfer methodology. Various (E)-2-nitrobenzaldehyde O-methyl oximes reacted easily with alcohols or benzyl amines to provide N-heterocyclic compounds in good to high yields. Similarly, the heterocyclic products could be prepared by the reaction of 1-(2-nitrophenyl)ethanone, urea and benzyl alcohols. I...

2017
Mohammad Asif

Heterocycles have vital interest in the pharmaceuticals and agrochemicals. Synthetic chemistry provides wealth of heterocyclic systems. More than 90% of drugs contain heterocycles ring and the interface between chemistry and biology. Scientific insight, discovery and applications are taking place by heterocyclic compounds. This review article covers theactive heterocycles that have shown consid...

Journal: :Dalton transactions 2015
Jessica L Drake Hilan Z Kaplan Matthew J T Wilding Bo Li Jeffery A Byers

In contrast to high spin pyridyl diimine iron(ii) dichloride complexes, analogous bis(amidinato)-N-heterocyclic carbene iron(ii) and iron(iii) complexes demonstrate complex magnetic behaviour. In the solid state, they are best described as intermediate spin complexes at low temperatures that demonstrate gradual spin transitions beginning near or below room temperature. Treating the bis(amidinat...

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