نتایج جستجو برای: halogen exchange fluorination

تعداد نتایج: 195602  

Journal: :Chemistry 2015
Jan Strueben Matthias Lipfert Jan-Ole Springer Colin A Gould Paul J Gates Frank D Sönnichsen Anne Staubitz

The lithiation of halogenated azobenzenes by halogen-lithium exchange commonly leads to substantial degradation of the azo group to give hydrazine derivatives besides the desired aryl lithium species. Yields of quenching reactions with electrophiles are therefore low. This work shows that a transmetalation reaction of easily accessible stannylated azobenzenes with methyllithium leads to a near-...

Journal: :Journal of chemical information and modeling 2014
Zhijian Xu Zhuo Yang Yingtao Liu Yunxiang Lu Kaixian Chen Weiliang Zhu

Halogen bond has attracted a great deal of attention in the past years for hit-to-lead-to-candidate optimization aiming at improving drug-target binding affinity. In general, heavy organohalogens (i.e., organochlorines, organobromines, and organoiodines) are capable of forming halogen bonds while organofluorines are not. In order to explore the possible roles that halogen bonds could play beyon...

Journal: :Physical chemistry chemical physics : PCCP 2016
Vytor Oliveira Elfi Kraka Dieter Cremer

36 halogen-bonded complexes YXARm (X: F, Cl, Br; Y: donor group; ARm acceptor group) have been investigated at the CCSD(T)/aug-cc-pVTZ level of theory. Binding energies, geometries, NBO charges, charge transfer, dipole moments, electrostatic potential, electron and energy density distributions, difference density distributions, vibrational frequencies, local stretching and bending force constan...

Journal: :Angewandte Chemie 2021

Abstract A new family of carbon‐bound boron enolates, generated by a kinetically controlled halogen exchange between chlorocatecholborane and silylketene acetals, is described. These C−boron enolates are demonstrated to activate 1,3‐enyne substrates in the presence Pd 0 /Senphos ligand complex, resulting first examples carboboration reaction an alkyne with enolate‐equivalent nucleophiles. Highl...

2012
Joseph C. Sloop Paul D. Boyle Augustus W. Fountain Cristina Gomez James L. Jackson William F. Pearman Robert D. Schmidt Jonathan Weyand

Several fluorinated and trifluoromethylated indanone, tetralone and naphthone derivatives have been prepared via Claisen condensations and selective fluorinations in yields ranging from 22–60%. In addition, we report the synthesis of new, selectively fluorinated bindones in yields ranging from 72–92%. Of particular interest is the fluorination and trifluoroacetylation regiochemistry observed in...

Journal: :Bioresource technology 2011
Faisal I Hai Nichanan Tadkaew James A McDonald Stuart J Khan Long D Nghiem

This study investigated the relationship between physicochemical properties (namely halogen content and hydrophobicity) of halogenated trace organics and their removal efficiencies by a laboratory scale membrane bioreactor (MBR) under stable operating conditions. The reported results demonstrated a combined effect of halogen content and hydrophobicity on the removal. Compounds with high halogen...

MP2 calculations with cc-pVTZ basis set were used to analyze intermolecular interactions in F3CX···YLi···NCCN and F3CX···NCCN···LiY triads (X = Cl, Br; Y = CN, NC) which are connected via halogen and lithium bonds. Those complexes with the role of LiY as halogen acceptor and lithium donor show cooperativity with energy values ranging between -1.97 and -2.92 kJ mol...

Journal: :Chemical communications 2012
Shu-Bin Zhao Rui-Yao Wang Ha Nguyen Jennifer J Becker Michel R Gagné

The electrophilic fluorination of several (triphos)Pt-aryl(+) establishes the first example of aryl-F coupling from a Pt center.

Journal: :Synfacts 2023

Key words fluorination - dienes hypervalent iodine difunctionalization

Journal: :Science China. Materials 2021

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) bring new opportunities for portable power generation due to their outstanding advantages such as high tolerance fuel/air impurities and simplified heat/water management. However, carbon-supported nanostructured Pt-based catalysts running at temperatures over 150°C are challenged by the severe aggregation carbon corrosion, thus le...

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