نتایج جستجو برای: fluorination

تعداد نتایج: 1361  

Journal: :Chemical communications 2015
Matthew B Nodwell Abhimanyu Bagai Shira D Halperin Rainer E Martin Henner Knust Robert Britton

The late-stage fluorination of common synthetic building blocks and drug leads is an appealing reaction for medicinal chemistry. In particular, fluorination of benzylic C-H bonds provides a means to attenuate drug metabolism at this metabolically labile position. Here we report two complimentary strategies for the direct fluorination of benzylic C-H bonds using N-fluorobenzenesulfonimide and ei...

Journal: :Angewandte Chemie 2017
Xinghua Ma Mohamed Diane Glenn Ralph Christine Chen Mark R Biscoe

We report the use of isolable primary and secondary alkylcarbastannatrane nucleophiles in site-specific fluorination reactions. These reactions occur without the need for transition metal catalysis or in situ activation of the nucleophile. In the absence of the carbastannatrane backbone, alkyltin nucleophiles exhibit no activity towards fluorination. When enantioenriched alkylcarbastannatranes ...

Journal: :Journal of the American Chemical Society 2011
Piotr Kwiatkowski Teresa D Beeson Jay C Conrad David W C MacMillan

The first highly enantioselective α-fluorination of ketones using organocatalysis has been accomplished. The long-standing problem of enantioselective ketone α-fluorination via enamine activation has been overcome via high-throughput evaluation of a new library of amine catalysts. The optimal system, a primary amine functionalized Cinchona alkaloid, allows the direct and asymmetric α-fluorinati...

2009
Alexander P. Kharitonov Larisa N. Kharitonova

The fundamental features and industrial applications of the direct fluorination of polymers are reviewed. Direct fluorination of polymers (i.e., treatment of a polymer surface with gaseous fluorine mixtures) proceeds spontaneously at room temperature and is a surface modification process. More than 25 polymers have been studied with the aid of a variety of analytical and spectroscopic technique...

Journal: :ACS catalysis 2015
Kenichi Hiramatsu Takashi Honjo Vivek Rauniyar F Dean Toste

Stereoselective synthesis of two fluorine-bearing drug-like scaffolds, dihydroquinazolone and benzooxazinone, has been accomplished through asymmetric fluorocyclization reactions initiated by the fluorination process. The reaction employs double axially chiral anionic phase-transfer catalysts to achieve high diastereo- and enantioselectivities, and a wide range of fluorine-containing dihydroqui...

Journal: :Molecules 2017
Taras M Sokolenko Maya I Dronkina Emmanuel Magnier Lev M Yagupolskii Yurii L Yagupolskii

The "chlorination/fluorination" technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

2004
L. K. Pan Y. K. Ee C. Q. Sun G. Q. Yu B. K. Tay

The effect of plasma fluorination on the band gap, 2p core-level energy, and the dielectric behavior of porous silicon ~PS! prepared under constant conditions has been examined using Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, photoluminescence, and reflection. It has been found that with increasing extent of fluorination, the band gap expands, and the 2p level an...

2015
Bin Yin Shinsuke Inagi Toshio Fuchigami

Anodic fluorination of dithioacetals bearing electron-withdrawing ester, acetyl, amide, and nitrile groups at their α-positions was comparatively studied using various supporting poly(HF) salts like Et3N·nHF (n = 3-5) and Et4NF·nHF (n = 3-5). In the former two cases, the corresponding α-fluorination products or fluorodesulfurization products were obtained selectively depending on supporting pol...

Journal: :Journal of Synthetic Organic Chemistry, Japan 1958

Journal: :Angewandte Chemie 2013
Theresa Liang Constanze N Neumann Tobias Ritter

Over the past decade, the most significant, conceptual advances in the field of fluorination were enabled most prominently by organo- and transition-metal catalysis. The most challenging transformation remains the formation of the parent C-F bond, primarily as a consequence of the high hydration energy of fluoride, strong metal-fluorine bonds, and highly polarized bonds to fluorine. Most fluori...

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